int (*rename2) (struct inode *, struct dentry *,
struct inode *, struct dentry *, unsigned int);
int (*readlink) (struct dentry *, char __user *,int);
- void * (*follow_link) (struct dentry *, struct nameidata *);
- void (*put_link) (struct dentry *, struct nameidata *, void *);
+ const char *(*follow_link) (struct dentry *, void **);
+ void (*put_link) (struct inode *, void *);
void (*truncate) (struct inode *);
int (*permission) (struct inode *, int, unsigned int);
int (*get_acl)(struct inode *, int);
-Support is available for filesystems that wish to do automounting support (such
-as kAFS which can be found in fs/afs/). This facility includes allowing
-in-kernel mounts to be performed and mountpoint degradation to be
-requested. The latter can also be requested by userspace.
+Support is available for filesystems that wish to do automounting
+support (such as kAFS which can be found in fs/afs/ and NFS in
+fs/nfs/). This facility includes allowing in-kernel mounts to be
+performed and mountpoint degradation to be requested. The latter can
+also be requested by userspace.
======================
IN-KERNEL AUTOMOUNTING
======================
-A filesystem can now mount another filesystem on one of its directories by the
-following procedure:
-
- (1) Give the directory a follow_link() operation.
-
- When the directory is accessed, the follow_link op will be called, and
- it will be provided with the location of the mountpoint in the nameidata
- structure (vfsmount and dentry).
-
- (2) Have the follow_link() op do the following steps:
-
- (a) Call vfs_kern_mount() to call the appropriate filesystem to set up a
- superblock and gain a vfsmount structure representing it.
-
- (b) Copy the nameidata provided as an argument and substitute the dentry
- argument into it the copy.
-
- (c) Call do_add_mount() to install the new vfsmount into the namespace's
- mountpoint tree, thus making it accessible to userspace. Use the
- nameidata set up in (b) as the destination.
-
- If the mountpoint will be automatically expired, then do_add_mount()
- should also be given the location of an expiration list (see further
- down).
-
- (d) Release the path in the nameidata argument and substitute in the new
- vfsmount and its root dentry. The ref counts on these will need
- incrementing.
+See section "Mount Traps" of Documentation/filesystems/autofs4.txt
Then from userspace, you can just do something like:
===========================
Automatic expiration of mountpoints is easy, provided you've mounted the
-mountpoint to be expired in the automounting procedure outlined above.
+mountpoint to be expired in the automounting procedure outlined separately.
To do expiration, you need to follow these steps:
- (3) Create at least one list off which the vfsmounts to be expired can be
- hung. Access to this list will be governed by the vfsmount_lock.
+ (1) Create at least one list off which the vfsmounts to be expired can be
+ hung.
- (4) In step (2c) above, the call to do_add_mount() should be provided with a
- pointer to this list. It will hang the vfsmount off of it if it succeeds.
+ (2) When a new mountpoint is created in the ->d_automount method, add
+ the mnt to the list using mnt_set_expiry()
+ mnt_set_expiry(newmnt, &afs_vfsmounts);
- (5) When you want mountpoints to be expired, call mark_mounts_for_expiry()
+ (3) When you want mountpoints to be expired, call mark_mounts_for_expiry()
with a pointer to this list. This will process the list, marking every
vfsmount thereon for potential expiry on the next call.
--
[mandatory]
->aio_read/->aio_write are gone. Use ->read_iter/->write_iter.
+---
+[recommended]
+ for embedded ("fast") symlinks just set inode->i_link to wherever the
+ symlink body is and use simple_follow_link() as ->follow_link().
+--
+[mandatory]
+ calling conventions for ->follow_link() have changed. Instead of returning
+ cookie and using nd_set_link() to store the body to traverse, we return
+ the body to traverse and store the cookie using explicit void ** argument.
+ nameidata isn't passed at all - nd_jump_link() doesn't need it and
+ nd_[gs]et_link() is gone.
+--
+[mandatory]
+ calling conventions for ->put_link() have changed. It gets inode instead of
+ dentry, it does not get nameidata at all and it gets called only when cookie
+ is non-NULL. Note that link body isn't available anymore, so if you need it,
+ store it as cookie.
int (*rename2) (struct inode *, struct dentry *,
struct inode *, struct dentry *, unsigned int);
int (*readlink) (struct dentry *, char __user *,int);
- void * (*follow_link) (struct dentry *, struct nameidata *);
- void (*put_link) (struct dentry *, struct nameidata *, void *);
+ const char *(*follow_link) (struct dentry *, void **);
+ void (*put_link) (struct inode *, void *);
int (*permission) (struct inode *, int);
int (*get_acl)(struct inode *, int);
int (*setattr) (struct dentry *, struct iattr *);
follow_link: called by the VFS to follow a symbolic link to the
inode it points to. Only required if you want to support
- symbolic links. This method returns a void pointer cookie
- that is passed to put_link().
+ symbolic links. This method returns the symlink body
+ to traverse (and possibly resets the current position with
+ nd_jump_link()). If the body won't go away until the inode
+ is gone, nothing else is needed; if it needs to be otherwise
+ pinned, the data needed to release whatever we'd grabbed
+ is to be stored in void * variable passed by address to
+ follow_link() instance.
put_link: called by the VFS to release resources allocated by
- follow_link(). The cookie returned by follow_link() is passed
- to this method as the last parameter. It is used by
- filesystems such as NFS where page cache is not stable
- (i.e. page that was installed when the symbolic link walk
- started might not be in the page cache at the end of the
- walk).
+ follow_link(). The cookie stored by follow_link() is passed
+ to this method as the last parameter; only called when
+ cookie isn't NULL.
permission: called by the VFS to check for access rights on a POSIX-like
filesystem.
#endif
-
-/*
- * After 3.1, kernel's nameidata.intent.open.flags is different
- * with lustre's lookup_intent.it_flags, as lustre's it_flags'
- * lower bits equal to FMODE_xxx while kernel doesn't transliterate
- * lower bits of nameidata.intent.open.flags to FMODE_xxx.
- * */
#include <linux/version.h>
-static inline int ll_namei_to_lookup_intent_flag(int flag)
-{
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 1, 0)
- flag = (flag & ~O_ACCMODE) | OPEN_FMODE(flag);
-#endif
- return flag;
-}
-
#include <linux/fs.h>
# define ll_umode_t umode_t
#define VM_FAULT_RETRY 0
#endif
-/* Kernel 3.1 kills LOOKUP_CONTINUE, LOOKUP_PARENT is equivalent to it.
- * seem kernel commit 49084c3bb2055c401f3493c13edae14d49128ca0 */
-#ifndef LOOKUP_CONTINUE
-#define LOOKUP_CONTINUE LOOKUP_PARENT
-#endif
-
/** Only used on client-side for indicating the tail of dir hash/offset. */
#define LL_DIR_END_OFF 0x7fffffffffffffffULL
#define LL_DIR_END_OFF_32BIT 0x7fffffffUL
return rc;
}
-static void *ll_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *ll_follow_link(struct dentry *dentry, void **cookie)
{
struct inode *inode = d_inode(dentry);
struct ptlrpc_request *request = NULL;
char *symname = NULL;
CDEBUG(D_VFSTRACE, "VFS Op\n");
- /* Limit the recursive symlink depth to 5 instead of default
- * 8 links when kernel has 4k stack to prevent stack overflow.
- * For 8k stacks we need to limit it to 7 for local servers. */
- if (THREAD_SIZE < 8192 && current->link_count >= 6) {
- rc = -ELOOP;
- } else if (THREAD_SIZE == 8192 && current->link_count >= 8) {
- rc = -ELOOP;
- } else {
- ll_inode_size_lock(inode);
- rc = ll_readlink_internal(inode, &request, &symname);
- ll_inode_size_unlock(inode);
- }
+ ll_inode_size_lock(inode);
+ rc = ll_readlink_internal(inode, &request, &symname);
+ ll_inode_size_unlock(inode);
if (rc) {
ptlrpc_req_finished(request);
- request = NULL;
- symname = ERR_PTR(rc);
+ return ERR_PTR(rc);
}
- nd_set_link(nd, symname);
/* symname may contain a pointer to the request message buffer,
* we delay request releasing until ll_put_link then.
*/
- return request;
+ *cookie = request;
+ return symname;
}
-static void ll_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
+static void ll_put_link(struct inode *unused, void *cookie)
{
ptlrpc_req_finished(cookie);
}
extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d);
extern int v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry);
-extern void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd,
- void *p);
extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses,
struct p9_fid *fid,
struct super_block *sb, int new);
}
/**
- * v9fs_readlink - read a symlink's location (internal version)
+ * v9fs_vfs_follow_link - follow a symlink path
* @dentry: dentry for symlink
- * @buffer: buffer to load symlink location into
- * @buflen: length of buffer
- *
+ * @cookie: place to pass the data to put_link()
*/
-static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
+static const char *v9fs_vfs_follow_link(struct dentry *dentry, void **cookie)
{
- int retval;
-
- struct v9fs_session_info *v9ses;
- struct p9_fid *fid;
+ struct v9fs_session_info *v9ses = v9fs_dentry2v9ses(dentry);
+ struct p9_fid *fid = v9fs_fid_lookup(dentry);
struct p9_wstat *st;
+ char *res;
+
+ p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
- p9_debug(P9_DEBUG_VFS, " %pd\n", dentry);
- retval = -EPERM;
- v9ses = v9fs_dentry2v9ses(dentry);
- fid = v9fs_fid_lookup(dentry);
if (IS_ERR(fid))
- return PTR_ERR(fid);
+ return ERR_CAST(fid);
if (!v9fs_proto_dotu(v9ses))
- return -EBADF;
+ return ERR_PTR(-EBADF);
st = p9_client_stat(fid);
if (IS_ERR(st))
- return PTR_ERR(st);
+ return ERR_CAST(st);
if (!(st->mode & P9_DMSYMLINK)) {
- retval = -EINVAL;
- goto done;
+ p9stat_free(st);
+ kfree(st);
+ return ERR_PTR(-EINVAL);
}
+ res = st->extension;
+ st->extension = NULL;
+ if (strlen(res) >= PATH_MAX)
+ res[PATH_MAX - 1] = '\0';
- /* copy extension buffer into buffer */
- retval = min(strlen(st->extension)+1, (size_t)buflen);
- memcpy(buffer, st->extension, retval);
-
- p9_debug(P9_DEBUG_VFS, "%pd -> %s (%.*s)\n",
- dentry, st->extension, buflen, buffer);
-
-done:
p9stat_free(st);
kfree(st);
- return retval;
-}
-
-/**
- * v9fs_vfs_follow_link - follow a symlink path
- * @dentry: dentry for symlink
- * @nd: nameidata
- *
- */
-
-static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- int len = 0;
- char *link = __getname();
-
- p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
-
- if (!link)
- link = ERR_PTR(-ENOMEM);
- else {
- len = v9fs_readlink(dentry, link, PATH_MAX);
-
- if (len < 0) {
- __putname(link);
- link = ERR_PTR(len);
- } else
- link[min(len, PATH_MAX-1)] = 0;
- }
- nd_set_link(nd, link);
-
- return NULL;
-}
-
-/**
- * v9fs_vfs_put_link - release a symlink path
- * @dentry: dentry for symlink
- * @nd: nameidata
- * @p: unused
- *
- */
-
-void
-v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
-{
- char *s = nd_get_link(nd);
-
- p9_debug(P9_DEBUG_VFS, " %pd %s\n",
- dentry, IS_ERR(s) ? "<error>" : s);
- if (!IS_ERR(s))
- __putname(s);
+ return *cookie = res;
}
/**
return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
}
+#define U32_MAX_DIGITS 10
+
/**
* v9fs_vfs_link - create a hardlink
* @old_dentry: dentry for file to link to
struct dentry *dentry)
{
int retval;
- char *name;
+ char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
struct p9_fid *oldfid;
p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
if (IS_ERR(oldfid))
return PTR_ERR(oldfid);
- name = __getname();
- if (unlikely(!name)) {
- retval = -ENOMEM;
- goto clunk_fid;
- }
-
sprintf(name, "%d\n", oldfid->fid);
retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
- __putname(name);
if (!retval) {
v9fs_refresh_inode(oldfid, d_inode(old_dentry));
v9fs_invalidate_inode_attr(dir);
}
-clunk_fid:
p9_client_clunk(oldfid);
return retval;
}
{
struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
int retval;
- char *name;
+ char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
u32 perm;
p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n",
if (!new_valid_dev(rdev))
return -EINVAL;
- name = __getname();
- if (!name)
- return -ENOMEM;
/* build extension */
if (S_ISBLK(mode))
sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
else if (S_ISCHR(mode))
sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
- else if (S_ISFIFO(mode))
- *name = 0;
- else if (S_ISSOCK(mode))
+ else
*name = 0;
- else {
- __putname(name);
- return -EINVAL;
- }
perm = unixmode2p9mode(v9ses, mode);
retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
- __putname(name);
return retval;
}
static const struct inode_operations v9fs_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = v9fs_vfs_follow_link,
- .put_link = v9fs_vfs_put_link,
+ .put_link = kfree_put_link,
.getattr = v9fs_vfs_getattr,
.setattr = v9fs_vfs_setattr,
};
/**
* v9fs_vfs_follow_link_dotl - follow a symlink path
* @dentry: dentry for symlink
- * @nd: nameidata
- *
+ * @cookie: place to pass the data to put_link()
*/
-static void *
-v9fs_vfs_follow_link_dotl(struct dentry *dentry, struct nameidata *nd)
+static const char *
+v9fs_vfs_follow_link_dotl(struct dentry *dentry, void **cookie)
{
- int retval;
- struct p9_fid *fid;
- char *link = __getname();
+ struct p9_fid *fid = v9fs_fid_lookup(dentry);
char *target;
+ int retval;
p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
- if (!link) {
- link = ERR_PTR(-ENOMEM);
- goto ndset;
- }
- fid = v9fs_fid_lookup(dentry);
- if (IS_ERR(fid)) {
- __putname(link);
- link = ERR_CAST(fid);
- goto ndset;
- }
+ if (IS_ERR(fid))
+ return ERR_CAST(fid);
retval = p9_client_readlink(fid, &target);
- if (!retval) {
- strcpy(link, target);
- kfree(target);
- goto ndset;
- }
- __putname(link);
- link = ERR_PTR(retval);
-ndset:
- nd_set_link(nd, link);
- return NULL;
+ if (retval)
+ return ERR_PTR(retval);
+ return *cookie = target;
}
int v9fs_refresh_inode_dotl(struct p9_fid *fid, struct inode *inode)
const struct inode_operations v9fs_symlink_inode_operations_dotl = {
.readlink = generic_readlink,
.follow_link = v9fs_vfs_follow_link_dotl,
- .put_link = v9fs_vfs_put_link,
+ .put_link = kfree_put_link,
.getattr = v9fs_vfs_getattr_dotl,
.setattr = v9fs_vfs_setattr_dotl,
.setxattr = generic_setxattr,
#include "autofs_i.h"
-static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *autofs4_follow_link(struct dentry *dentry, void **cookie)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
if (ino && !autofs4_oz_mode(sbi))
ino->last_used = jiffies;
- nd_set_link(nd, d_inode(dentry)->i_private);
- return NULL;
+ return d_inode(dentry)->i_private;
}
const struct inode_operations autofs4_symlink_inode_operations = {
static struct inode *befs_alloc_inode(struct super_block *sb);
static void befs_destroy_inode(struct inode *inode);
static void befs_destroy_inodecache(void);
-static void *befs_follow_link(struct dentry *, struct nameidata *);
-static void *befs_fast_follow_link(struct dentry *, struct nameidata *);
+static const char *befs_follow_link(struct dentry *, void **);
static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
char **out, int *out_len);
static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
.bmap = befs_bmap,
};
-static const struct inode_operations befs_fast_symlink_inode_operations = {
- .readlink = generic_readlink,
- .follow_link = befs_fast_follow_link,
-};
-
static const struct inode_operations befs_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = befs_follow_link,
inode->i_op = &befs_dir_inode_operations;
inode->i_fop = &befs_dir_operations;
} else if (S_ISLNK(inode->i_mode)) {
- if (befs_ino->i_flags & BEFS_LONG_SYMLINK)
+ if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
inode->i_op = &befs_symlink_inode_operations;
- else
- inode->i_op = &befs_fast_symlink_inode_operations;
+ } else {
+ inode->i_link = befs_ino->i_data.symlink;
+ inode->i_op = &simple_symlink_inode_operations;
+ }
} else {
befs_error(sb, "Inode %lu is not a regular file, "
"directory or symlink. THAT IS WRONG! BeFS has no "
* The data stream become link name. Unless the LONG_SYMLINK
* flag is set.
*/
-static void *
-befs_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *
+befs_follow_link(struct dentry *dentry, void **cookie)
{
struct super_block *sb = dentry->d_sb;
struct befs_inode_info *befs_ino = BEFS_I(d_inode(dentry));
if (len == 0) {
befs_error(sb, "Long symlink with illegal length");
- link = ERR_PTR(-EIO);
- } else {
- befs_debug(sb, "Follow long symlink");
-
- link = kmalloc(len, GFP_NOFS);
- if (!link) {
- link = ERR_PTR(-ENOMEM);
- } else if (befs_read_lsymlink(sb, data, link, len) != len) {
- kfree(link);
- befs_error(sb, "Failed to read entire long symlink");
- link = ERR_PTR(-EIO);
- } else {
- link[len - 1] = '\0';
- }
+ return ERR_PTR(-EIO);
}
- nd_set_link(nd, link);
- return NULL;
-}
-
-
-static void *
-befs_fast_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- struct befs_inode_info *befs_ino = BEFS_I(d_inode(dentry));
+ befs_debug(sb, "Follow long symlink");
- nd_set_link(nd, befs_ino->i_data.symlink);
- return NULL;
+ link = kmalloc(len, GFP_NOFS);
+ if (!link)
+ return ERR_PTR(-ENOMEM);
+ if (befs_read_lsymlink(sb, data, link, len) != len) {
+ kfree(link);
+ befs_error(sb, "Failed to read entire long symlink");
+ return ERR_PTR(-EIO);
+ }
+ link[len - 1] = '\0';
+ return *cookie = link;
}
/*
#include <linux/string.h>
#include <linux/uaccess.h>
#include <linux/kernel.h>
-#include <linux/namei.h>
#include <linux/writeback.h>
#include <linux/vmalloc.h>
#include <linux/posix_acl.h>
else
kfree(sym); /* lost a race */
}
+ inode->i_link = ci->i_symlink;
break;
case S_IFDIR:
inode->i_op = &ceph_dir_iops;
/*
* symlinks
*/
-static void *ceph_sym_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- struct ceph_inode_info *ci = ceph_inode(d_inode(dentry));
- nd_set_link(nd, ci->i_symlink);
- return NULL;
-}
-
static const struct inode_operations ceph_symlink_iops = {
.readlink = generic_readlink,
- .follow_link = ceph_sym_follow_link,
+ .follow_link = simple_follow_link,
.setattr = ceph_setattr,
.getattr = ceph_getattr,
.setxattr = ceph_setxattr,
#endif
/* Functions related to symlinks */
-extern void *cifs_follow_link(struct dentry *direntry, struct nameidata *nd);
+extern const char *cifs_follow_link(struct dentry *direntry, void **cookie);
extern int cifs_readlink(struct dentry *direntry, char __user *buffer,
int buflen);
extern int cifs_symlink(struct inode *inode, struct dentry *direntry,
return rc;
}
-void *
-cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
+const char *
+cifs_follow_link(struct dentry *direntry, void **cookie)
{
struct inode *inode = d_inode(direntry);
int rc = -ENOMEM;
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink)) {
- rc = PTR_ERR(tlink);
- tlink = NULL;
- goto out;
+ free_xid(xid);
+ return ERR_CAST(tlink);
}
tcon = tlink_tcon(tlink);
server = tcon->ses->server;
full_path = build_path_from_dentry(direntry);
- if (!full_path)
- goto out;
+ if (!full_path) {
+ free_xid(xid);
+ cifs_put_tlink(tlink);
+ return ERR_PTR(-ENOMEM);
+ }
cifs_dbg(FYI, "Full path: %s inode = 0x%p\n", full_path, inode);
&target_path, cifs_sb);
kfree(full_path);
-out:
+ free_xid(xid);
+ cifs_put_tlink(tlink);
if (rc != 0) {
kfree(target_path);
- target_path = ERR_PTR(rc);
+ return ERR_PTR(rc);
}
-
- free_xid(xid);
- if (tlink)
- cifs_put_tlink(tlink);
- nd_set_link(nd, target_path);
- return NULL;
+ return *cookie = target_path;
}
int
}
-static void *configfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *configfs_follow_link(struct dentry *dentry, void **cookie)
{
- int error = -ENOMEM;
unsigned long page = get_zeroed_page(GFP_KERNEL);
+ int error;
- if (page) {
- error = configfs_getlink(dentry, (char *)page);
- if (!error) {
- nd_set_link(nd, (char *)page);
- return (void *)page;
- }
- }
-
- nd_set_link(nd, ERR_PTR(error));
- return NULL;
-}
+ if (!page)
+ return ERR_PTR(-ENOMEM);
-static void configfs_put_link(struct dentry *dentry, struct nameidata *nd,
- void *cookie)
-{
- if (cookie) {
- unsigned long page = (unsigned long)cookie;
- free_page(page);
+ error = configfs_getlink(dentry, (char *)page);
+ if (!error) {
+ return *cookie = (void *)page;
}
+
+ free_page(page);
+ return ERR_PTR(error);
}
const struct inode_operations configfs_symlink_inode_operations = {
.follow_link = configfs_follow_link,
.readlink = generic_readlink,
- .put_link = configfs_put_link,
+ .put_link = free_page_put_link,
.setattr = configfs_setattr,
};
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/pagemap.h>
-#include <linux/namei.h>
#include <linux/debugfs.h>
#include <linux/io.h>
#include <linux/slab.h>
.llseek = noop_llseek,
};
-static void *debugfs_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- nd_set_link(nd, d_inode(dentry)->i_private);
- return NULL;
-}
-
-const struct inode_operations debugfs_link_operations = {
- .readlink = generic_readlink,
- .follow_link = debugfs_follow_link,
-};
-
static int debugfs_u8_set(void *data, u64 val)
{
*(u8 *)data = val;
truncate_inode_pages_final(&inode->i_data);
clear_inode(inode);
if (S_ISLNK(inode->i_mode))
- kfree(inode->i_private);
+ kfree(inode->i_link);
}
static const struct super_operations debugfs_super_operations = {
return failed_creating(dentry);
}
inode->i_mode = S_IFLNK | S_IRWXUGO;
- inode->i_op = &debugfs_link_operations;
- inode->i_private = link;
+ inode->i_op = &simple_symlink_inode_operations;
+ inode->i_link = link;
d_instantiate(dentry, inode);
return end_creating(dentry);
}
* @directory_inode: inode of the new file's dentry's parent in ecryptfs
* @ecryptfs_dentry: New file's dentry in ecryptfs
* @mode: The mode of the new file
- * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
*
* Creates the underlying file and the eCryptfs inode which will link to
* it. It will also update the eCryptfs directory inode to mimic the
* ecryptfs_lookup
* @ecryptfs_dir_inode: The eCryptfs directory inode
* @ecryptfs_dentry: The eCryptfs dentry that we are looking up
- * @ecryptfs_nd: nameidata; may be NULL
+ * @flags: lookup flags
*
* Find a file on disk. If the file does not exist, then we'll add it to the
* dentry cache and continue on to read it from the disk.
return rc ? ERR_PTR(rc) : buf;
}
-static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *ecryptfs_follow_link(struct dentry *dentry, void **cookie)
{
size_t len;
char *buf = ecryptfs_readlink_lower(dentry, &len);
if (IS_ERR(buf))
- goto out;
+ return buf;
fsstack_copy_attr_atime(d_inode(dentry),
d_inode(ecryptfs_dentry_to_lower(dentry)));
buf[len] = '\0';
-out:
- nd_set_link(nd, buf);
- return NULL;
+ return *cookie = buf;
}
/**
libore-y := ore.o ore_raid.o
obj-$(CONFIG_ORE) += libore.o
-exofs-y := inode.o file.o symlink.o namei.o dir.o super.o sys.o
+exofs-y := inode.o file.o namei.o dir.o super.o sys.o
obj-$(CONFIG_EXOFS_FS) += exofs.o
extern const struct inode_operations exofs_dir_inode_operations;
extern const struct inode_operations exofs_special_inode_operations;
-/* symlink.c */
-extern const struct inode_operations exofs_symlink_inode_operations;
-extern const struct inode_operations exofs_fast_symlink_inode_operations;
-
/* exofs_init_comps will initialize an ore_components device array
* pointing to a single ore_comp struct, and a round-robin view
* of the device table.
inode->i_fop = &exofs_dir_operations;
inode->i_mapping->a_ops = &exofs_aops;
} else if (S_ISLNK(inode->i_mode)) {
- if (exofs_inode_is_fast_symlink(inode))
- inode->i_op = &exofs_fast_symlink_inode_operations;
- else {
- inode->i_op = &exofs_symlink_inode_operations;
+ if (exofs_inode_is_fast_symlink(inode)) {
+ inode->i_op = &simple_symlink_inode_operations;
+ inode->i_link = (char *)oi->i_data;
+ } else {
+ inode->i_op = &page_symlink_inode_operations;
inode->i_mapping->a_ops = &exofs_aops;
}
} else {
oi = exofs_i(inode);
if (l > sizeof(oi->i_data)) {
/* slow symlink */
- inode->i_op = &exofs_symlink_inode_operations;
+ inode->i_op = &page_symlink_inode_operations;
inode->i_mapping->a_ops = &exofs_aops;
memset(oi->i_data, 0, sizeof(oi->i_data));
goto out_fail;
} else {
/* fast symlink */
- inode->i_op = &exofs_fast_symlink_inode_operations;
+ inode->i_op = &simple_symlink_inode_operations;
+ inode->i_link = (char *)oi->i_data;
memcpy(oi->i_data, symname, l);
inode->i_size = l-1;
}
+++ /dev/null
-/*
- * Copyright (C) 2005, 2006
- * Avishay Traeger (avishay@gmail.com)
- * Copyright (C) 2008, 2009
- * Boaz Harrosh <ooo@electrozaur.com>
- *
- * Copyrights for code taken from ext2:
- * Copyright (C) 1992, 1993, 1994, 1995
- * Remy Card (card@masi.ibp.fr)
- * Laboratoire MASI - Institut Blaise Pascal
- * Universite Pierre et Marie Curie (Paris VI)
- * from
- * linux/fs/minix/inode.c
- * Copyright (C) 1991, 1992 Linus Torvalds
- *
- * This file is part of exofs.
- *
- * exofs is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation. Since it is based on ext2, and the only
- * valid version of GPL for the Linux kernel is version 2, the only valid
- * version of GPL for exofs is version 2.
- *
- * exofs is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with exofs; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <linux/namei.h>
-
-#include "exofs.h"
-
-static void *exofs_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- struct exofs_i_info *oi = exofs_i(d_inode(dentry));
-
- nd_set_link(nd, (char *)oi->i_data);
- return NULL;
-}
-
-const struct inode_operations exofs_symlink_inode_operations = {
- .readlink = generic_readlink,
- .follow_link = page_follow_link_light,
- .put_link = page_put_link,
-};
-
-const struct inode_operations exofs_fast_symlink_inode_operations = {
- .readlink = generic_readlink,
- .follow_link = exofs_follow_link,
-};
inode->i_mapping->a_ops = &ext2_aops;
} else if (S_ISLNK(inode->i_mode)) {
if (ext2_inode_is_fast_symlink(inode)) {
+ inode->i_link = (char *)ei->i_data;
inode->i_op = &ext2_fast_symlink_inode_operations;
nd_terminate_link(ei->i_data, inode->i_size,
sizeof(ei->i_data) - 1);
} else {
/* fast symlink */
inode->i_op = &ext2_fast_symlink_inode_operations;
- memcpy((char*)(EXT2_I(inode)->i_data),symname,l);
+ inode->i_link = (char*)EXT2_I(inode)->i_data;
+ memcpy(inode->i_link, symname, l);
inode->i_size = l-1;
}
mark_inode_dirty(inode);
#include "ext2.h"
#include "xattr.h"
-#include <linux/namei.h>
-
-static void *ext2_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- struct ext2_inode_info *ei = EXT2_I(d_inode(dentry));
- nd_set_link(nd, (char *)ei->i_data);
- return NULL;
-}
const struct inode_operations ext2_symlink_inode_operations = {
.readlink = generic_readlink,
const struct inode_operations ext2_fast_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = ext2_follow_link,
+ .follow_link = simple_follow_link,
.setattr = ext2_setattr,
#ifdef CONFIG_EXT2_FS_XATTR
.setxattr = generic_setxattr,
inode->i_op = &ext3_fast_symlink_inode_operations;
nd_terminate_link(ei->i_data, inode->i_size,
sizeof(ei->i_data) - 1);
+ inode->i_link = (char *)ei->i_data;
} else {
inode->i_op = &ext3_symlink_inode_operations;
ext3_set_aops(inode);
}
} else {
inode->i_op = &ext3_fast_symlink_inode_operations;
- memcpy((char*)&EXT3_I(inode)->i_data,symname,l);
+ inode->i_link = (char*)&EXT3_I(inode)->i_data;
+ memcpy(inode->i_link, symname, l);
inode->i_size = l-1;
}
EXT3_I(inode)->i_disksize = inode->i_size;
* ext3 symlink handling code
*/
-#include <linux/namei.h>
#include "ext3.h"
#include "xattr.h"
-static void * ext3_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- struct ext3_inode_info *ei = EXT3_I(d_inode(dentry));
- nd_set_link(nd, (char*)ei->i_data);
- return NULL;
-}
-
const struct inode_operations ext3_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = page_follow_link_light,
const struct inode_operations ext3_fast_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = ext3_follow_link,
+ .follow_link = simple_follow_link,
.setattr = ext3_setattr,
#ifdef CONFIG_EXT3_FS_XATTR
.setxattr = generic_setxattr,
unsigned nr_pages);
/* symlink.c */
+extern const struct inode_operations ext4_encrypted_symlink_inode_operations;
extern const struct inode_operations ext4_symlink_inode_operations;
extern const struct inode_operations ext4_fast_symlink_inode_operations;
inode->i_op = &ext4_dir_inode_operations;
inode->i_fop = &ext4_dir_operations;
} else if (S_ISLNK(inode->i_mode)) {
- if (ext4_inode_is_fast_symlink(inode) &&
- !ext4_encrypted_inode(inode)) {
+ if (ext4_encrypted_inode(inode)) {
+ inode->i_op = &ext4_encrypted_symlink_inode_operations;
+ ext4_set_aops(inode);
+ } else if (ext4_inode_is_fast_symlink(inode)) {
+ inode->i_link = (char *)ei->i_data;
inode->i_op = &ext4_fast_symlink_inode_operations;
nd_terminate_link(ei->i_data, inode->i_size,
sizeof(ei->i_data) - 1);
goto err_drop_inode;
sd->len = cpu_to_le16(ostr.len);
disk_link.name = (char *) sd;
+ inode->i_op = &ext4_encrypted_symlink_inode_operations;
}
if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
- inode->i_op = &ext4_symlink_inode_operations;
+ if (!encryption_required)
+ inode->i_op = &ext4_symlink_inode_operations;
ext4_set_aops(inode);
/*
* We cannot call page_symlink() with transaction started
} else {
/* clear the extent format for fast symlink */
ext4_clear_inode_flag(inode, EXT4_INODE_EXTENTS);
- inode->i_op = encryption_required ?
- &ext4_symlink_inode_operations :
- &ext4_fast_symlink_inode_operations;
+ if (!encryption_required) {
+ inode->i_op = &ext4_fast_symlink_inode_operations;
+ inode->i_link = (char *)&EXT4_I(inode)->i_data;
+ }
memcpy((char *)&EXT4_I(inode)->i_data, disk_link.name,
disk_link.len);
inode->i_size = disk_link.len - 1;
#include "xattr.h"
#ifdef CONFIG_EXT4_FS_ENCRYPTION
-static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *ext4_follow_link(struct dentry *dentry, void **cookie)
{
struct page *cpage = NULL;
char *caddr, *paddr = NULL;
int res;
u32 plen, max_size = inode->i_sb->s_blocksize;
- if (!ext4_encrypted_inode(inode))
- return page_follow_link_light(dentry, nd);
-
ctx = ext4_get_fname_crypto_ctx(inode, inode->i_sb->s_blocksize);
if (IS_ERR(ctx))
- return ctx;
+ return ERR_CAST(ctx);
if (ext4_inode_is_fast_symlink(inode)) {
caddr = (char *) EXT4_I(inode)->i_data;
cpage = read_mapping_page(inode->i_mapping, 0, NULL);
if (IS_ERR(cpage)) {
ext4_put_fname_crypto_ctx(&ctx);
- return cpage;
+ return ERR_CAST(cpage);
}
caddr = kmap(cpage);
caddr[size] = 0;
/* Null-terminate the name */
if (res <= plen)
paddr[res] = '\0';
- nd_set_link(nd, paddr);
ext4_put_fname_crypto_ctx(&ctx);
if (cpage) {
kunmap(cpage);
page_cache_release(cpage);
}
- return NULL;
+ return *cookie = paddr;
errout:
ext4_put_fname_crypto_ctx(&ctx);
if (cpage) {
return ERR_PTR(res);
}
-static void ext4_put_link(struct dentry *dentry, struct nameidata *nd,
- void *cookie)
-{
- struct page *page = cookie;
-
- if (!page) {
- kfree(nd_get_link(nd));
- } else {
- kunmap(page);
- page_cache_release(page);
- }
-}
+const struct inode_operations ext4_encrypted_symlink_inode_operations = {
+ .readlink = generic_readlink,
+ .follow_link = ext4_follow_link,
+ .put_link = kfree_put_link,
+ .setattr = ext4_setattr,
+ .setxattr = generic_setxattr,
+ .getxattr = generic_getxattr,
+ .listxattr = ext4_listxattr,
+ .removexattr = generic_removexattr,
+};
#endif
-static void *ext4_follow_fast_link(struct dentry *dentry, struct nameidata *nd)
-{
- struct ext4_inode_info *ei = EXT4_I(d_inode(dentry));
- nd_set_link(nd, (char *) ei->i_data);
- return NULL;
-}
-
const struct inode_operations ext4_symlink_inode_operations = {
.readlink = generic_readlink,
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
- .follow_link = ext4_follow_link,
- .put_link = ext4_put_link,
-#else
.follow_link = page_follow_link_light,
.put_link = page_put_link,
-#endif
.setattr = ext4_setattr,
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
const struct inode_operations ext4_fast_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = ext4_follow_fast_link,
+ .follow_link = simple_follow_link,
.setattr = ext4_setattr,
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
return err;
}
-static void *f2fs_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *f2fs_follow_link(struct dentry *dentry, void **cookie)
{
- struct page *page = page_follow_link_light(dentry, nd);
-
- if (IS_ERR_OR_NULL(page))
- return page;
-
- /* this is broken symlink case */
- if (*nd_get_link(nd) == 0) {
- page_put_link(dentry, nd, page);
- return ERR_PTR(-ENOENT);
+ const char *link = page_follow_link_light(dentry, cookie);
+ if (!IS_ERR(link) && !*link) {
+ /* this is broken symlink case */
+ page_put_link(NULL, *cookie);
+ link = ERR_PTR(-ENOENT);
}
- return page;
+ return link;
}
static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
/* vxfs_fshead.c */
extern int vxfs_read_fshead(struct super_block *);
-/* vxfs_immed.c */
-extern const struct inode_operations vxfs_immed_symlink_iops;
-
/* vxfs_inode.c */
extern const struct address_space_operations vxfs_immed_aops;
extern struct kmem_cache *vxfs_inode_cachep;
*/
#include <linux/fs.h>
#include <linux/pagemap.h>
-#include <linux/namei.h>
#include "vxfs.h"
#include "vxfs_extern.h"
#include "vxfs_inode.h"
-static void * vxfs_immed_follow_link(struct dentry *, struct nameidata *);
-
static int vxfs_immed_readpage(struct file *, struct page *);
-/*
- * Inode operations for immed symlinks.
- *
- * Unliked all other operations we do not go through the pagecache,
- * but do all work directly on the inode.
- */
-const struct inode_operations vxfs_immed_symlink_iops = {
- .readlink = generic_readlink,
- .follow_link = vxfs_immed_follow_link,
-};
-
/*
* Address space operations for immed files and directories.
*/
.readpage = vxfs_immed_readpage,
};
-/**
- * vxfs_immed_follow_link - follow immed symlink
- * @dp: dentry for the link
- * @np: pathname lookup data for the current path walk
- *
- * Description:
- * vxfs_immed_follow_link restarts the pathname lookup with
- * the data obtained from @dp.
- *
- * Returns:
- * Zero on success, else a negative error code.
- */
-static void *
-vxfs_immed_follow_link(struct dentry *dp, struct nameidata *np)
-{
- struct vxfs_inode_info *vip = VXFS_INO(d_inode(dp));
- nd_set_link(np, vip->vii_immed.vi_immed);
- return NULL;
-}
-
/**
* vxfs_immed_readpage - read part of an immed inode into pagecache
* @file: file context (unused)
#include <linux/pagemap.h>
#include <linux/kernel.h>
#include <linux/slab.h>
+#include <linux/namei.h>
#include "vxfs.h"
#include "vxfs_inode.h"
ip->i_op = &page_symlink_inode_operations;
ip->i_mapping->a_ops = &vxfs_aops;
} else {
- ip->i_op = &vxfs_immed_symlink_iops;
- vip->vii_immed.vi_immed[ip->i_size] = '\0';
+ ip->i_op = &simple_symlink_inode_operations;
+ ip->i_link = vip->vii_immed.vi_immed;
+ nd_terminate_link(ip->i_link, ip->i_size,
+ sizeof(vip->vii_immed.vi_immed) - 1);
}
} else
init_special_inode(ip, ip->i_mode, old_decode_dev(vip->vii_rdev));
return err;
}
-static char *read_link(struct dentry *dentry)
+static const char *fuse_follow_link(struct dentry *dentry, void **cookie)
{
struct inode *inode = d_inode(dentry);
struct fuse_conn *fc = get_fuse_conn(inode);
link = ERR_PTR(ret);
} else {
link[ret] = '\0';
+ *cookie = link;
}
fuse_invalidate_atime(inode);
return link;
}
-static void free_link(char *link)
-{
- if (!IS_ERR(link))
- free_page((unsigned long) link);
-}
-
-static void *fuse_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- nd_set_link(nd, read_link(dentry));
- return NULL;
-}
-
-static void fuse_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
-{
- free_link(nd_get_link(nd));
-}
-
static int fuse_dir_open(struct inode *inode, struct file *file)
{
return fuse_open_common(inode, file, true);
static const struct inode_operations fuse_symlink_inode_operations = {
.setattr = fuse_setattr,
.follow_link = fuse_follow_link,
- .put_link = fuse_put_link,
+ .put_link = free_page_put_link,
.readlink = generic_readlink,
.getattr = fuse_getattr,
.setxattr = fuse_setxattr,
* Returns: 0 on success or error code
*/
-static void *gfs2_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *gfs2_follow_link(struct dentry *dentry, void **cookie)
{
struct gfs2_inode *ip = GFS2_I(d_inode(dentry));
struct gfs2_holder i_gh;
error = gfs2_glock_nq(&i_gh);
if (error) {
gfs2_holder_uninit(&i_gh);
- nd_set_link(nd, ERR_PTR(error));
- return NULL;
+ return ERR_PTR(error);
}
size = (unsigned int)i_size_read(&ip->i_inode);
brelse(dibh);
out:
gfs2_glock_dq_uninit(&i_gh);
- nd_set_link(nd, buf);
- return NULL;
+ if (!IS_ERR(buf))
+ *cookie = buf;
+ return buf;
}
/**
.setattr = hostfs_setattr,
};
-static void *hostfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *hostfs_follow_link(struct dentry *dentry, void **cookie)
{
char *link = __getname();
if (link) {
}
if (err < 0) {
__putname(link);
- link = ERR_PTR(err);
+ return ERR_PTR(err);
}
} else {
- link = ERR_PTR(-ENOMEM);
+ return ERR_PTR(-ENOMEM);
}
- nd_set_link(nd, link);
- return NULL;
+ return *cookie = link;
}
-static void hostfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
+static void hostfs_put_link(struct inode *unused, void *cookie)
{
- char *s = nd_get_link(nd);
- if (!IS_ERR(s))
- __putname(s);
+ __putname(cookie);
}
static const struct inode_operations hostfs_link_iops = {
buflen);
}
-static void *hppfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *hppfs_follow_link(struct dentry *dentry, void **cookie)
{
struct dentry *proc_dentry = HPPFS_I(d_inode(dentry))->proc_dentry;
- return d_inode(proc_dentry)->i_op->follow_link(proc_dentry, nd);
+ return d_inode(proc_dentry)->i_op->follow_link(proc_dentry, cookie);
}
-static void hppfs_put_link(struct dentry *dentry, struct nameidata *nd,
- void *cookie)
+static void hppfs_put_link(struct inode *inode, void *cookie)
{
- struct dentry *proc_dentry = HPPFS_I(d_inode(dentry))->proc_dentry;
+ struct inode *proc_inode = d_inode(HPPFS_I(inode)->proc_dentry);
- if (d_inode(proc_dentry)->i_op->put_link)
- d_inode(proc_dentry)->i_op->put_link(proc_dentry, nd, cookie);
+ if (proc_inode->i_op->put_link)
+ proc_inode->i_op->put_link(proc_inode, cookie);
}
static const struct inode_operations hppfs_dir_iops = {
inode->i_pipe = NULL;
inode->i_bdev = NULL;
inode->i_cdev = NULL;
+ inode->i_link = NULL;
inode->i_rdev = 0;
inode->dirtied_when = 0;
* This function automatically handles read only file systems and media,
* as well as the "noatime" flag and inode specific "noatime" markers.
*/
-void touch_atime(const struct path *path)
+bool atime_needs_update(const struct path *path, struct inode *inode)
{
struct vfsmount *mnt = path->mnt;
- struct inode *inode = d_inode(path->dentry);
struct timespec now;
if (inode->i_flags & S_NOATIME)
- return;
+ return false;
if (IS_NOATIME(inode))
- return;
+ return false;
if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode))
- return;
+ return false;
if (mnt->mnt_flags & MNT_NOATIME)
- return;
+ return false;
if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))
- return;
+ return false;
now = current_fs_time(inode->i_sb);
if (!relatime_need_update(mnt, inode, now))
- return;
+ return false;
if (timespec_equal(&inode->i_atime, &now))
+ return false;
+
+ return true;
+}
+
+void touch_atime(const struct path *path)
+{
+ struct vfsmount *mnt = path->mnt;
+ struct inode *inode = d_inode(path->dentry);
+ struct timespec now;
+
+ if (!atime_needs_update(path, inode))
return;
if (!sb_start_write_trylock(inode->i_sb))
return;
- if (__mnt_want_write(mnt))
+ if (__mnt_want_write(mnt) != 0)
goto skip_update;
/*
* File systems can error out when updating inodes if they need to
* We may also fail on filesystems that have the ability to make parts
* of the fs read only, e.g. subvolumes in Btrfs.
*/
+ now = current_fs_time(inode->i_sb);
update_time(inode, &now, S_ATIME);
__mnt_drop_write(mnt);
skip_update:
ret = -ENOMEM;
goto fail;
}
+ inode->i_link = f->target;
jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
__func__, (char *)f->target);
case S_IFLNK:
inode->i_op = &jffs2_symlink_inode_operations;
+ inode->i_link = f->target;
break;
case S_IFDIR:
*
*/
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/namei.h>
#include "nodelist.h"
-static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd);
-
const struct inode_operations jffs2_symlink_inode_operations =
{
.readlink = generic_readlink,
- .follow_link = jffs2_follow_link,
+ .follow_link = simple_follow_link,
.setattr = jffs2_setattr,
.setxattr = jffs2_setxattr,
.getxattr = jffs2_getxattr,
.listxattr = jffs2_listxattr,
.removexattr = jffs2_removexattr
};
-
-static void *jffs2_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(dentry));
- char *p = (char *)f->target;
-
- /*
- * We don't acquire the f->sem mutex here since the only data we
- * use is f->target.
- *
- * 1. If we are here the inode has already built and f->target has
- * to point to the target path.
- * 2. Nobody uses f->target (if the inode is symlink's inode). The
- * exception is inode freeing function which frees f->target. But
- * it can't be called while we are here and before VFS has
- * stopped using our f->target string which we provide by means of
- * nd_set_link() call.
- */
-
- if (!p) {
- pr_err("%s(): can't find symlink target\n", __func__);
- p = ERR_PTR(-EIO);
- }
- jffs2_dbg(1, "%s(): target path is '%s'\n",
- __func__, (char *)f->target);
-
- nd_set_link(nd, p);
-
- /*
- * We will unlock the f->sem mutex but VFS will use the f->target string. This is safe
- * since the only way that may cause f->target to be changed is iput() operation.
- * But VFS will not use f->target after iput() has been called.
- */
- return NULL;
-}
-
inode->i_mapping->a_ops = &jfs_aops;
} else {
inode->i_op = &jfs_fast_symlink_inode_operations;
+ inode->i_link = JFS_IP(inode)->i_inline;
/*
* The inline data should be null-terminated, but
* don't let on-disk corruption crash the kernel
*/
- JFS_IP(inode)->i_inline[inode->i_size] = '\0';
+ inode->i_link[inode->i_size] = '\0';
}
} else {
inode->i_op = &jfs_file_inode_operations;
int ssize; /* source pathname size */
struct btstack btstack;
struct inode *ip = d_inode(dentry);
- unchar *i_fastsymlink;
s64 xlen = 0;
int bmask = 0, xsize;
s64 xaddr;
if (ssize <= IDATASIZE) {
ip->i_op = &jfs_fast_symlink_inode_operations;
- i_fastsymlink = JFS_IP(ip)->i_inline;
- memcpy(i_fastsymlink, name, ssize);
+ ip->i_link = JFS_IP(ip)->i_inline;
+ memcpy(ip->i_link, name, ssize);
ip->i_size = ssize - 1;
/*
*/
#include <linux/fs.h>
-#include <linux/namei.h>
#include "jfs_incore.h"
#include "jfs_inode.h"
#include "jfs_xattr.h"
-static void *jfs_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- char *s = JFS_IP(d_inode(dentry))->i_inline;
- nd_set_link(nd, s);
- return NULL;
-}
-
const struct inode_operations jfs_fast_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = jfs_follow_link,
+ .follow_link = simple_follow_link,
.setattr = jfs_setattr,
.setxattr = jfs_setxattr,
.getxattr = jfs_getxattr,
return error;
}
-static void *kernfs_iop_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *kernfs_iop_follow_link(struct dentry *dentry, void **cookie)
{
int error = -ENOMEM;
unsigned long page = get_zeroed_page(GFP_KERNEL);
- if (page) {
- error = kernfs_getlink(dentry, (char *) page);
- if (error < 0)
- free_page((unsigned long)page);
- }
- nd_set_link(nd, error ? ERR_PTR(error) : (char *)page);
- return NULL;
-}
-
-static void kernfs_iop_put_link(struct dentry *dentry, struct nameidata *nd,
- void *cookie)
-{
- char *page = nd_get_link(nd);
- if (!IS_ERR(page))
+ if (!page)
+ return ERR_PTR(-ENOMEM);
+ error = kernfs_getlink(dentry, (char *)page);
+ if (unlikely(error < 0)) {
free_page((unsigned long)page);
+ return ERR_PTR(error);
+ }
+ return *cookie = (char *)page;
}
const struct inode_operations kernfs_symlink_iops = {
.listxattr = kernfs_iop_listxattr,
.readlink = generic_readlink,
.follow_link = kernfs_iop_follow_link,
- .put_link = kernfs_iop_put_link,
+ .put_link = free_page_put_link,
.setattr = kernfs_iop_setattr,
.getattr = kernfs_iop_getattr,
.permission = kernfs_iop_permission,
}
EXPORT_SYMBOL(noop_fsync);
-void kfree_put_link(struct dentry *dentry, struct nameidata *nd,
- void *cookie)
+void kfree_put_link(struct inode *unused, void *cookie)
{
- char *s = nd_get_link(nd);
- if (!IS_ERR(s))
- kfree(s);
+ kfree(cookie);
}
EXPORT_SYMBOL(kfree_put_link);
+void free_page_put_link(struct inode *unused, void *cookie)
+{
+ free_page((unsigned long) cookie);
+}
+EXPORT_SYMBOL(free_page_put_link);
+
/*
* nop .set_page_dirty method so that people can use .page_mkwrite on
* anon inodes.
return -EINVAL;
}
EXPORT_SYMBOL(simple_nosetlease);
+
+const char *simple_follow_link(struct dentry *dentry, void **cookie)
+{
+ return d_inode(dentry)->i_link;
+}
+EXPORT_SYMBOL(simple_follow_link);
+
+const struct inode_operations simple_symlink_inode_operations = {
+ .follow_link = simple_follow_link,
+ .readlink = generic_readlink
+};
+EXPORT_SYMBOL(simple_symlink_inode_operations);
const struct inode_operations logfs_symlink_iops = {
.readlink = generic_readlink,
.follow_link = page_follow_link_light,
+ .put_link = page_put_link,
};
const struct inode_operations logfs_dir_iops = {
extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *);
extern struct mount *__lookup_mnt_last(struct vfsmount *, struct dentry *);
+extern int __legitimize_mnt(struct vfsmount *, unsigned);
extern bool legitimize_mnt(struct vfsmount *, unsigned);
extern void __detach_mounts(struct dentry *dentry);
}
EXPORT_SYMBOL(path_put);
+#define EMBEDDED_LEVELS 2
struct nameidata {
struct path path;
struct qstr last;
unsigned seq, m_seq;
int last_type;
unsigned depth;
- struct file *base;
- char *saved_names[MAX_NESTED_LINKS + 1];
+ int total_link_count;
+ struct saved {
+ struct path link;
+ void *cookie;
+ const char *name;
+ struct inode *inode;
+ unsigned seq;
+ } *stack, internal[EMBEDDED_LEVELS];
+ struct filename *name;
+ struct nameidata *saved;
+ unsigned root_seq;
+ int dfd;
};
+static void set_nameidata(struct nameidata *p, int dfd, struct filename *name)
+{
+ struct nameidata *old = current->nameidata;
+ p->stack = p->internal;
+ p->dfd = dfd;
+ p->name = name;
+ p->total_link_count = old ? old->total_link_count : 0;
+ p->saved = old;
+ current->nameidata = p;
+}
+
+static void restore_nameidata(void)
+{
+ struct nameidata *now = current->nameidata, *old = now->saved;
+
+ current->nameidata = old;
+ if (old)
+ old->total_link_count = now->total_link_count;
+ if (now->stack != now->internal) {
+ kfree(now->stack);
+ now->stack = now->internal;
+ }
+}
+
+static int __nd_alloc_stack(struct nameidata *nd)
+{
+ struct saved *p;
+
+ if (nd->flags & LOOKUP_RCU) {
+ p= kmalloc(MAXSYMLINKS * sizeof(struct saved),
+ GFP_ATOMIC);
+ if (unlikely(!p))
+ return -ECHILD;
+ } else {
+ p= kmalloc(MAXSYMLINKS * sizeof(struct saved),
+ GFP_KERNEL);
+ if (unlikely(!p))
+ return -ENOMEM;
+ }
+ memcpy(p, nd->internal, sizeof(nd->internal));
+ nd->stack = p;
+ return 0;
+}
+
+static inline int nd_alloc_stack(struct nameidata *nd)
+{
+ if (likely(nd->depth != EMBEDDED_LEVELS))
+ return 0;
+ if (likely(nd->stack != nd->internal))
+ return 0;
+ return __nd_alloc_stack(nd);
+}
+
+static void drop_links(struct nameidata *nd)
+{
+ int i = nd->depth;
+ while (i--) {
+ struct saved *last = nd->stack + i;
+ struct inode *inode = last->inode;
+ if (last->cookie && inode->i_op->put_link) {
+ inode->i_op->put_link(inode, last->cookie);
+ last->cookie = NULL;
+ }
+ }
+}
+
+static void terminate_walk(struct nameidata *nd)
+{
+ drop_links(nd);
+ if (!(nd->flags & LOOKUP_RCU)) {
+ int i;
+ path_put(&nd->path);
+ for (i = 0; i < nd->depth; i++)
+ path_put(&nd->stack[i].link);
+ if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
+ path_put(&nd->root);
+ nd->root.mnt = NULL;
+ }
+ } else {
+ nd->flags &= ~LOOKUP_RCU;
+ if (!(nd->flags & LOOKUP_ROOT))
+ nd->root.mnt = NULL;
+ rcu_read_unlock();
+ }
+ nd->depth = 0;
+}
+
+/* path_put is needed afterwards regardless of success or failure */
+static bool legitimize_path(struct nameidata *nd,
+ struct path *path, unsigned seq)
+{
+ int res = __legitimize_mnt(path->mnt, nd->m_seq);
+ if (unlikely(res)) {
+ if (res > 0)
+ path->mnt = NULL;
+ path->dentry = NULL;
+ return false;
+ }
+ if (unlikely(!lockref_get_not_dead(&path->dentry->d_lockref))) {
+ path->dentry = NULL;
+ return false;
+ }
+ return !read_seqcount_retry(&path->dentry->d_seq, seq);
+}
+
+static bool legitimize_links(struct nameidata *nd)
+{
+ int i;
+ for (i = 0; i < nd->depth; i++) {
+ struct saved *last = nd->stack + i;
+ if (unlikely(!legitimize_path(nd, &last->link, last->seq))) {
+ drop_links(nd);
+ nd->depth = i + 1;
+ return false;
+ }
+ }
+ return true;
+}
+
/*
* Path walking has 2 modes, rcu-walk and ref-walk (see
* Documentation/filesystems/path-lookup.txt). In situations when we can't
* unlazy_walk - try to switch to ref-walk mode.
* @nd: nameidata pathwalk data
* @dentry: child of nd->path.dentry or NULL
+ * @seq: seq number to check dentry against
* Returns: 0 on success, -ECHILD on failure
*
* unlazy_walk attempts to legitimize the current nd->path, nd->root and dentry
* for ref-walk mode. @dentry must be a path found by a do_lookup call on
* @nd or NULL. Must be called from rcu-walk context.
+ * Nothing should touch nameidata between unlazy_walk() failure and
+ * terminate_walk().
*/
-static int unlazy_walk(struct nameidata *nd, struct dentry *dentry)
+static int unlazy_walk(struct nameidata *nd, struct dentry *dentry, unsigned seq)
{
- struct fs_struct *fs = current->fs;
struct dentry *parent = nd->path.dentry;
BUG_ON(!(nd->flags & LOOKUP_RCU));
- /*
- * After legitimizing the bastards, terminate_walk()
- * will do the right thing for non-RCU mode, and all our
- * subsequent exit cases should rcu_read_unlock()
- * before returning. Do vfsmount first; if dentry
- * can't be legitimized, just set nd->path.dentry to NULL
- * and rely on dput(NULL) being a no-op.
- */
- if (!legitimize_mnt(nd->path.mnt, nd->m_seq))
- return -ECHILD;
nd->flags &= ~LOOKUP_RCU;
-
- if (!lockref_get_not_dead(&parent->d_lockref)) {
- nd->path.dentry = NULL;
- goto out;
- }
+ if (unlikely(!legitimize_links(nd)))
+ goto out2;
+ if (unlikely(!legitimize_mnt(nd->path.mnt, nd->m_seq)))
+ goto out2;
+ if (unlikely(!lockref_get_not_dead(&parent->d_lockref)))
+ goto out1;
/*
* For a negative lookup, the lookup sequence point is the parents
} else {
if (!lockref_get_not_dead(&dentry->d_lockref))
goto out;
- if (read_seqcount_retry(&dentry->d_seq, nd->seq))
+ if (read_seqcount_retry(&dentry->d_seq, seq))
goto drop_dentry;
}
* still valid and get it if required.
*/
if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
- spin_lock(&fs->lock);
- if (nd->root.mnt != fs->root.mnt || nd->root.dentry != fs->root.dentry)
- goto unlock_and_drop_dentry;
- path_get(&nd->root);
- spin_unlock(&fs->lock);
+ if (unlikely(!legitimize_path(nd, &nd->root, nd->root_seq))) {
+ rcu_read_unlock();
+ dput(dentry);
+ return -ECHILD;
+ }
}
rcu_read_unlock();
return 0;
-unlock_and_drop_dentry:
- spin_unlock(&fs->lock);
drop_dentry:
rcu_read_unlock();
dput(dentry);
goto drop_root_mnt;
+out2:
+ nd->path.mnt = NULL;
+out1:
+ nd->path.dentry = NULL;
out:
rcu_read_unlock();
drop_root_mnt:
return -ECHILD;
}
+static int unlazy_link(struct nameidata *nd, struct path *link, unsigned seq)
+{
+ if (unlikely(!legitimize_path(nd, link, seq))) {
+ drop_links(nd);
+ nd->depth = 0;
+ nd->flags &= ~LOOKUP_RCU;
+ nd->path.mnt = NULL;
+ nd->path.dentry = NULL;
+ if (!(nd->flags & LOOKUP_ROOT))
+ nd->root.mnt = NULL;
+ rcu_read_unlock();
+ } else if (likely(unlazy_walk(nd, NULL, 0)) == 0) {
+ return 0;
+ }
+ path_put(link);
+ return -ECHILD;
+}
+
static inline int d_revalidate(struct dentry *dentry, unsigned int flags)
{
return dentry->d_op->d_revalidate(dentry, flags);
int status;
if (nd->flags & LOOKUP_RCU) {
- nd->flags &= ~LOOKUP_RCU;
if (!(nd->flags & LOOKUP_ROOT))
nd->root.mnt = NULL;
-
- if (!legitimize_mnt(nd->path.mnt, nd->m_seq)) {
- rcu_read_unlock();
- return -ECHILD;
- }
- if (unlikely(!lockref_get_not_dead(&dentry->d_lockref))) {
- rcu_read_unlock();
- mntput(nd->path.mnt);
+ if (unlikely(unlazy_walk(nd, NULL, 0)))
return -ECHILD;
- }
- if (read_seqcount_retry(&dentry->d_seq, nd->seq)) {
- rcu_read_unlock();
- dput(dentry);
- mntput(nd->path.mnt);
- return -ECHILD;
- }
- rcu_read_unlock();
}
if (likely(!(nd->flags & LOOKUP_JUMPED)))
if (!status)
status = -ESTALE;
- path_put(&nd->path);
return status;
}
-static __always_inline void set_root(struct nameidata *nd)
+static void set_root(struct nameidata *nd)
{
get_fs_root(current->fs, &nd->root);
}
-static int link_path_walk(const char *, struct nameidata *);
-
-static __always_inline unsigned set_root_rcu(struct nameidata *nd)
+static unsigned set_root_rcu(struct nameidata *nd)
{
struct fs_struct *fs = current->fs;
- unsigned seq, res;
+ unsigned seq;
do {
seq = read_seqcount_begin(&fs->seq);
nd->root = fs->root;
- res = __read_seqcount_begin(&nd->root.dentry->d_seq);
+ nd->root_seq = __read_seqcount_begin(&nd->root.dentry->d_seq);
} while (read_seqcount_retry(&fs->seq, seq));
- return res;
+ return nd->root_seq;
}
static void path_put_conditional(struct path *path, struct nameidata *nd)
* Helper to directly jump to a known parsed path from ->follow_link,
* caller must have taken a reference to path beforehand.
*/
-void nd_jump_link(struct nameidata *nd, struct path *path)
+void nd_jump_link(struct path *path)
{
+ struct nameidata *nd = current->nameidata;
path_put(&nd->path);
nd->path = *path;
nd->flags |= LOOKUP_JUMPED;
}
-void nd_set_link(struct nameidata *nd, char *path)
-{
- nd->saved_names[nd->depth] = path;
-}
-EXPORT_SYMBOL(nd_set_link);
-
-char *nd_get_link(struct nameidata *nd)
-{
- return nd->saved_names[nd->depth];
-}
-EXPORT_SYMBOL(nd_get_link);
-
-static inline void put_link(struct nameidata *nd, struct path *link, void *cookie)
+static inline void put_link(struct nameidata *nd)
{
- struct inode *inode = link->dentry->d_inode;
- if (inode->i_op->put_link)
- inode->i_op->put_link(link->dentry, nd, cookie);
- path_put(link);
+ struct saved *last = nd->stack + --nd->depth;
+ struct inode *inode = last->inode;
+ if (last->cookie && inode->i_op->put_link)
+ inode->i_op->put_link(inode, last->cookie);
+ if (!(nd->flags & LOOKUP_RCU))
+ path_put(&last->link);
}
int sysctl_protected_symlinks __read_mostly = 0;
/**
* may_follow_link - Check symlink following for unsafe situations
- * @link: The path of the symlink
* @nd: nameidata pathwalk data
*
* In the case of the sysctl_protected_symlinks sysctl being enabled,
*
* Returns 0 if following the symlink is allowed, -ve on error.
*/
-static inline int may_follow_link(struct path *link, struct nameidata *nd)
+static inline int may_follow_link(struct nameidata *nd)
{
const struct inode *inode;
const struct inode *parent;
return 0;
/* Allowed if owner and follower match. */
- inode = link->dentry->d_inode;
+ inode = nd->stack[0].inode;
if (uid_eq(current_cred()->fsuid, inode->i_uid))
return 0;
if (uid_eq(parent->i_uid, inode->i_uid))
return 0;
- audit_log_link_denied("follow_link", link);
- path_put_conditional(link, nd);
- path_put(&nd->path);
+ if (nd->flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ audit_log_link_denied("follow_link", &nd->stack[0].link);
return -EACCES;
}
return -EPERM;
}
-static __always_inline int
-follow_link(struct path *link, struct nameidata *nd, void **p)
+static __always_inline
+const char *get_link(struct nameidata *nd)
{
- struct dentry *dentry = link->dentry;
+ struct saved *last = nd->stack + nd->depth - 1;
+ struct dentry *dentry = last->link.dentry;
+ struct inode *inode = last->inode;
int error;
- char *s;
+ const char *res;
- BUG_ON(nd->flags & LOOKUP_RCU);
-
- if (link->mnt == nd->path.mnt)
- mntget(link->mnt);
-
- error = -ELOOP;
- if (unlikely(current->total_link_count >= 40))
- goto out_put_nd_path;
-
- cond_resched();
- current->total_link_count++;
-
- touch_atime(link);
- nd_set_link(nd, NULL);
+ if (!(nd->flags & LOOKUP_RCU)) {
+ touch_atime(&last->link);
+ cond_resched();
+ } else if (atime_needs_update(&last->link, inode)) {
+ if (unlikely(unlazy_walk(nd, NULL, 0)))
+ return ERR_PTR(-ECHILD);
+ touch_atime(&last->link);
+ }
- error = security_inode_follow_link(link->dentry, nd);
- if (error)
- goto out_put_nd_path;
+ error = security_inode_follow_link(dentry, inode,
+ nd->flags & LOOKUP_RCU);
+ if (unlikely(error))
+ return ERR_PTR(error);
nd->last_type = LAST_BIND;
- *p = dentry->d_inode->i_op->follow_link(dentry, nd);
- error = PTR_ERR(*p);
- if (IS_ERR(*p))
- goto out_put_nd_path;
-
- error = 0;
- s = nd_get_link(nd);
- if (s) {
- if (unlikely(IS_ERR(s))) {
- path_put(&nd->path);
- put_link(nd, link, *p);
- return PTR_ERR(s);
+ res = inode->i_link;
+ if (!res) {
+ if (nd->flags & LOOKUP_RCU) {
+ if (unlikely(unlazy_walk(nd, NULL, 0)))
+ return ERR_PTR(-ECHILD);
}
- if (*s == '/') {
+ res = inode->i_op->follow_link(dentry, &last->cookie);
+ if (IS_ERR_OR_NULL(res)) {
+ last->cookie = NULL;
+ return res;
+ }
+ }
+ if (*res == '/') {
+ if (nd->flags & LOOKUP_RCU) {
+ struct dentry *d;
+ if (!nd->root.mnt)
+ set_root_rcu(nd);
+ nd->path = nd->root;
+ d = nd->path.dentry;
+ nd->inode = d->d_inode;
+ nd->seq = nd->root_seq;
+ if (unlikely(read_seqcount_retry(&d->d_seq, nd->seq)))
+ return ERR_PTR(-ECHILD);
+ } else {
if (!nd->root.mnt)
set_root(nd);
path_put(&nd->path);
nd->path = nd->root;
path_get(&nd->root);
- nd->flags |= LOOKUP_JUMPED;
+ nd->inode = nd->path.dentry->d_inode;
}
- nd->inode = nd->path.dentry->d_inode;
- error = link_path_walk(s, nd);
- if (unlikely(error))
- put_link(nd, link, *p);
+ nd->flags |= LOOKUP_JUMPED;
+ while (unlikely(*++res == '/'))
+ ;
}
-
- return error;
-
-out_put_nd_path:
- *p = NULL;
- path_put(&nd->path);
- path_put(link);
- return error;
-}
-
-static int follow_up_rcu(struct path *path)
-{
- struct mount *mnt = real_mount(path->mnt);
- struct mount *parent;
- struct dentry *mountpoint;
-
- parent = mnt->mnt_parent;
- if (&parent->mnt == path->mnt)
- return 0;
- mountpoint = mnt->mnt_mountpoint;
- path->dentry = mountpoint;
- path->mnt = &parent->mnt;
- return 1;
+ if (!*res)
+ res = NULL;
+ return res;
}
/*
* - return -EISDIR to tell follow_managed() to stop and return the path we
* were called with.
*/
-static int follow_automount(struct path *path, unsigned flags,
+static int follow_automount(struct path *path, struct nameidata *nd,
bool *need_mntput)
{
struct vfsmount *mnt;
* as being automount points. These will need the attentions
* of the daemon to instantiate them before they can be used.
*/
- if (!(flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY |
- LOOKUP_OPEN | LOOKUP_CREATE | LOOKUP_AUTOMOUNT)) &&
+ if (!(nd->flags & (LOOKUP_PARENT | LOOKUP_DIRECTORY |
+ LOOKUP_OPEN | LOOKUP_CREATE | LOOKUP_AUTOMOUNT)) &&
path->dentry->d_inode)
return -EISDIR;
- current->total_link_count++;
- if (current->total_link_count >= 40)
+ nd->total_link_count++;
+ if (nd->total_link_count >= 40)
return -ELOOP;
mnt = path->dentry->d_op->d_automount(path);
* the path being looked up; if it wasn't then the remainder of
* the path is inaccessible and we should say so.
*/
- if (PTR_ERR(mnt) == -EISDIR && (flags & LOOKUP_PARENT))
+ if (PTR_ERR(mnt) == -EISDIR && (nd->flags & LOOKUP_PARENT))
return -EREMOTE;
return PTR_ERR(mnt);
}
*
* Serialization is taken care of in namespace.c
*/
-static int follow_managed(struct path *path, unsigned flags)
+static int follow_managed(struct path *path, struct nameidata *nd)
{
struct vfsmount *mnt = path->mnt; /* held by caller, must be left alone */
unsigned managed;
/* Handle an automount point */
if (managed & DCACHE_NEED_AUTOMOUNT) {
- ret = follow_automount(path, flags, &need_mntput);
+ ret = follow_automount(path, nd, &need_mntput);
if (ret < 0)
break;
continue;
mntput(path->mnt);
if (ret == -EISDIR)
ret = 0;
- return ret < 0 ? ret : need_mntput;
+ if (need_mntput)
+ nd->flags |= LOOKUP_JUMPED;
+ if (unlikely(ret < 0))
+ path_put_conditional(path, nd);
+ return ret;
}
int follow_down_one(struct path *path)
* we meet a managed dentry that would need blocking.
*/
static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
- struct inode **inode)
+ struct inode **inode, unsigned *seqp)
{
for (;;) {
struct mount *mounted;
path->mnt = &mounted->mnt;
path->dentry = mounted->mnt.mnt_root;
nd->flags |= LOOKUP_JUMPED;
- nd->seq = read_seqcount_begin(&path->dentry->d_seq);
+ *seqp = read_seqcount_begin(&path->dentry->d_seq);
/*
* Update the inode too. We don't need to re-check the
* dentry sequence number here after this d_inode read,
set_root_rcu(nd);
while (1) {
- if (nd->path.dentry == nd->root.dentry &&
- nd->path.mnt == nd->root.mnt) {
+ if (path_equal(&nd->path, &nd->root))
break;
- }
if (nd->path.dentry != nd->path.mnt->mnt_root) {
struct dentry *old = nd->path.dentry;
struct dentry *parent = old->d_parent;
inode = parent->d_inode;
seq = read_seqcount_begin(&parent->d_seq);
- if (read_seqcount_retry(&old->d_seq, nd->seq))
- goto failed;
+ if (unlikely(read_seqcount_retry(&old->d_seq, nd->seq)))
+ return -ECHILD;
nd->path.dentry = parent;
nd->seq = seq;
break;
+ } else {
+ struct mount *mnt = real_mount(nd->path.mnt);
+ struct mount *mparent = mnt->mnt_parent;
+ struct dentry *mountpoint = mnt->mnt_mountpoint;
+ struct inode *inode2 = mountpoint->d_inode;
+ unsigned seq = read_seqcount_begin(&mountpoint->d_seq);
+ if (unlikely(read_seqretry(&mount_lock, nd->m_seq)))
+ return -ECHILD;
+ if (&mparent->mnt == nd->path.mnt)
+ break;
+ /* we know that mountpoint was pinned */
+ nd->path.dentry = mountpoint;
+ nd->path.mnt = &mparent->mnt;
+ inode = inode2;
+ nd->seq = seq;
}
- if (!follow_up_rcu(&nd->path))
- break;
- inode = nd->path.dentry->d_inode;
- nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
}
- while (d_mountpoint(nd->path.dentry)) {
+ while (unlikely(d_mountpoint(nd->path.dentry))) {
struct mount *mounted;
mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry);
+ if (unlikely(read_seqretry(&mount_lock, nd->m_seq)))
+ return -ECHILD;
if (!mounted)
break;
nd->path.mnt = &mounted->mnt;
nd->path.dentry = mounted->mnt.mnt_root;
inode = nd->path.dentry->d_inode;
nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
- if (read_seqretry(&mount_lock, nd->m_seq))
- goto failed;
}
nd->inode = inode;
return 0;
-
-failed:
- nd->flags &= ~LOOKUP_RCU;
- if (!(nd->flags & LOOKUP_ROOT))
- nd->root.mnt = NULL;
- rcu_read_unlock();
- return -ECHILD;
}
/*
* It _is_ time-critical.
*/
static int lookup_fast(struct nameidata *nd,
- struct path *path, struct inode **inode)
+ struct path *path, struct inode **inode,
+ unsigned *seqp)
{
struct vfsmount *mnt = nd->path.mnt;
struct dentry *dentry, *parent = nd->path.dentry;
* This sequence count validates that the inode matches
* the dentry name information from lookup.
*/
- *inode = dentry->d_inode;
+ *inode = d_backing_inode(dentry);
negative = d_is_negative(dentry);
if (read_seqcount_retry(&dentry->d_seq, seq))
return -ECHILD;
*/
if (__read_seqcount_retry(&parent->d_seq, nd->seq))
return -ECHILD;
- nd->seq = seq;
+ *seqp = seq;
if (unlikely(dentry->d_flags & DCACHE_OP_REVALIDATE)) {
status = d_revalidate(dentry, nd->flags);
if (unlikely(status <= 0)) {
}
path->mnt = mnt;
path->dentry = dentry;
- if (likely(__follow_mount_rcu(nd, path, inode)))
+ if (likely(__follow_mount_rcu(nd, path, inode, seqp)))
return 0;
unlazy:
- if (unlazy_walk(nd, dentry))
+ if (unlazy_walk(nd, dentry, seq))
return -ECHILD;
} else {
dentry = __d_lookup(parent, &nd->last);
}
path->mnt = mnt;
path->dentry = dentry;
- err = follow_managed(path, nd->flags);
- if (unlikely(err < 0)) {
- path_put_conditional(path, nd);
- return err;
- }
- if (err)
- nd->flags |= LOOKUP_JUMPED;
- *inode = path->dentry->d_inode;
- return 0;
+ err = follow_managed(path, nd);
+ if (likely(!err))
+ *inode = d_backing_inode(path->dentry);
+ return err;
need_lookup:
return 1;
static int lookup_slow(struct nameidata *nd, struct path *path)
{
struct dentry *dentry, *parent;
- int err;
parent = nd->path.dentry;
BUG_ON(nd->inode != parent->d_inode);
return PTR_ERR(dentry);
path->mnt = nd->path.mnt;
path->dentry = dentry;
- err = follow_managed(path, nd->flags);
- if (unlikely(err < 0)) {
- path_put_conditional(path, nd);
- return err;
- }
- if (err)
- nd->flags |= LOOKUP_JUMPED;
- return 0;
+ return follow_managed(path, nd);
}
static inline int may_lookup(struct nameidata *nd)
int err = inode_permission(nd->inode, MAY_EXEC|MAY_NOT_BLOCK);
if (err != -ECHILD)
return err;
- if (unlazy_walk(nd, NULL))
+ if (unlazy_walk(nd, NULL, 0))
return -ECHILD;
}
return inode_permission(nd->inode, MAY_EXEC);
{
if (type == LAST_DOTDOT) {
if (nd->flags & LOOKUP_RCU) {
- if (follow_dotdot_rcu(nd))
- return -ECHILD;
+ return follow_dotdot_rcu(nd);
} else
follow_dotdot(nd);
}
return 0;
}
-static void terminate_walk(struct nameidata *nd)
+static int pick_link(struct nameidata *nd, struct path *link,
+ struct inode *inode, unsigned seq)
{
+ int error;
+ struct saved *last;
+ if (unlikely(nd->total_link_count++ >= MAXSYMLINKS)) {
+ path_to_nameidata(link, nd);
+ return -ELOOP;
+ }
if (!(nd->flags & LOOKUP_RCU)) {
- path_put(&nd->path);
- } else {
- nd->flags &= ~LOOKUP_RCU;
- if (!(nd->flags & LOOKUP_ROOT))
- nd->root.mnt = NULL;
- rcu_read_unlock();
+ if (link->mnt == nd->path.mnt)
+ mntget(link->mnt);
+ }
+ error = nd_alloc_stack(nd);
+ if (unlikely(error)) {
+ if (error == -ECHILD) {
+ if (unlikely(unlazy_link(nd, link, seq)))
+ return -ECHILD;
+ error = nd_alloc_stack(nd);
+ }
+ if (error) {
+ path_put(link);
+ return error;
+ }
}
+
+ last = nd->stack + nd->depth++;
+ last->link = *link;
+ last->cookie = NULL;
+ last->inode = inode;
+ last->seq = seq;
+ return 1;
}
/*
* so we keep a cache of "no, this doesn't need follow_link"
* for the common case.
*/
-static inline int should_follow_link(struct dentry *dentry, int follow)
+static inline int should_follow_link(struct nameidata *nd, struct path *link,
+ int follow,
+ struct inode *inode, unsigned seq)
{
- return unlikely(d_is_symlink(dentry)) ? follow : 0;
+ if (likely(!d_is_symlink(link->dentry)))
+ return 0;
+ if (!follow)
+ return 0;
+ return pick_link(nd, link, inode, seq);
}
-static inline int walk_component(struct nameidata *nd, struct path *path,
- int follow)
+enum {WALK_GET = 1, WALK_PUT = 2};
+
+static int walk_component(struct nameidata *nd, int flags)
{
+ struct path path;
struct inode *inode;
+ unsigned seq;
int err;
/*
* "." and ".." are special - ".." especially so because it has
* to be able to know about the current root directory and
* parent relationships.
*/
- if (unlikely(nd->last_type != LAST_NORM))
- return handle_dots(nd, nd->last_type);
- err = lookup_fast(nd, path, &inode);
+ if (unlikely(nd->last_type != LAST_NORM)) {
+ err = handle_dots(nd, nd->last_type);
+ if (flags & WALK_PUT)
+ put_link(nd);
+ return err;
+ }
+ err = lookup_fast(nd, &path, &inode, &seq);
if (unlikely(err)) {
if (err < 0)
- goto out_err;
+ return err;
- err = lookup_slow(nd, path);
+ err = lookup_slow(nd, &path);
if (err < 0)
- goto out_err;
+ return err;
- inode = path->dentry->d_inode;
+ inode = d_backing_inode(path.dentry);
+ seq = 0; /* we are already out of RCU mode */
err = -ENOENT;
- if (d_is_negative(path->dentry))
+ if (d_is_negative(path.dentry))
goto out_path_put;
}
- if (should_follow_link(path->dentry, follow)) {
- if (nd->flags & LOOKUP_RCU) {
- if (unlikely(nd->path.mnt != path->mnt ||
- unlazy_walk(nd, path->dentry))) {
- err = -ECHILD;
- goto out_err;
- }
- }
- BUG_ON(inode != path->dentry->d_inode);
- return 1;
- }
- path_to_nameidata(path, nd);
+ if (flags & WALK_PUT)
+ put_link(nd);
+ err = should_follow_link(nd, &path, flags & WALK_GET, inode, seq);
+ if (unlikely(err))
+ return err;
+ path_to_nameidata(&path, nd);
nd->inode = inode;
+ nd->seq = seq;
return 0;
out_path_put:
- path_to_nameidata(path, nd);
-out_err:
- terminate_walk(nd);
+ path_to_nameidata(&path, nd);
return err;
}
-/*
- * This limits recursive symlink follows to 8, while
- * limiting consecutive symlinks to 40.
- *
- * Without that kind of total limit, nasty chains of consecutive
- * symlinks can cause almost arbitrarily long lookups.
- */
-static inline int nested_symlink(struct path *path, struct nameidata *nd)
-{
- int res;
-
- if (unlikely(current->link_count >= MAX_NESTED_LINKS)) {
- path_put_conditional(path, nd);
- path_put(&nd->path);
- return -ELOOP;
- }
- BUG_ON(nd->depth >= MAX_NESTED_LINKS);
-
- nd->depth++;
- current->link_count++;
-
- do {
- struct path link = *path;
- void *cookie;
-
- res = follow_link(&link, nd, &cookie);
- if (res)
- break;
- res = walk_component(nd, path, LOOKUP_FOLLOW);
- put_link(nd, &link, cookie);
- } while (res > 0);
-
- current->link_count--;
- nd->depth--;
- return res;
-}
-
/*
* We can do the critical dentry name comparison and hashing
* operations one word at a time, but we are limited to:
*/
static int link_path_walk(const char *name, struct nameidata *nd)
{
- struct path next;
int err;
-
+
while (*name=='/')
name++;
if (!*name)
err = may_lookup(nd);
if (err)
- break;
+ return err;
hash_len = hash_name(name);
struct qstr this = { { .hash_len = hash_len }, .name = name };
err = parent->d_op->d_hash(parent, &this);
if (err < 0)
- break;
+ return err;
hash_len = this.hash_len;
name = this.name;
}
name += hashlen_len(hash_len);
if (!*name)
- return 0;
+ goto OK;
/*
* If it wasn't NUL, we know it was '/'. Skip that
* slash, and continue until no more slashes.
do {
name++;
} while (unlikely(*name == '/'));
- if (!*name)
- return 0;
-
- err = walk_component(nd, &next, LOOKUP_FOLLOW);
+ if (unlikely(!*name)) {
+OK:
+ /* pathname body, done */
+ if (!nd->depth)
+ return 0;
+ name = nd->stack[nd->depth - 1].name;
+ /* trailing symlink, done */
+ if (!name)
+ return 0;
+ /* last component of nested symlink */
+ err = walk_component(nd, WALK_GET | WALK_PUT);
+ } else {
+ err = walk_component(nd, WALK_GET);
+ }
if (err < 0)
return err;
if (err) {
- err = nested_symlink(&next, nd);
- if (err)
- return err;
- }
- if (!d_can_lookup(nd->path.dentry)) {
- err = -ENOTDIR;
- break;
+ const char *s = get_link(nd);
+
+ if (unlikely(IS_ERR(s)))
+ return PTR_ERR(s);
+ err = 0;
+ if (unlikely(!s)) {
+ /* jumped */
+ put_link(nd);
+ } else {
+ nd->stack[nd->depth - 1].name = name;
+ name = s;
+ continue;
+ }
}
+ if (unlikely(!d_can_lookup(nd->path.dentry)))
+ return -ENOTDIR;
}
- terminate_walk(nd);
- return err;
}
-static int path_init(int dfd, const struct filename *name, unsigned int flags,
- struct nameidata *nd)
+static const char *path_init(struct nameidata *nd, unsigned flags)
{
int retval = 0;
- const char *s = name->name;
+ const char *s = nd->name->name;
nd->last_type = LAST_ROOT; /* if there are only slashes... */
nd->flags = flags | LOOKUP_JUMPED | LOOKUP_PARENT;
nd->depth = 0;
- nd->base = NULL;
+ nd->total_link_count = 0;
if (flags & LOOKUP_ROOT) {
struct dentry *root = nd->root.dentry;
struct inode *inode = root->d_inode;
if (*s) {
if (!d_can_lookup(root))
- return -ENOTDIR;
+ return ERR_PTR(-ENOTDIR);
retval = inode_permission(inode, MAY_EXEC);
if (retval)
- return retval;
+ return ERR_PTR(retval);
}
nd->path = nd->root;
nd->inode = inode;
if (flags & LOOKUP_RCU) {
rcu_read_lock();
nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
+ nd->root_seq = nd->seq;
nd->m_seq = read_seqbegin(&mount_lock);
} else {
path_get(&nd->path);
}
- goto done;
+ return s;
}
nd->root.mnt = NULL;
path_get(&nd->root);
}
nd->path = nd->root;
- } else if (dfd == AT_FDCWD) {
+ } else if (nd->dfd == AT_FDCWD) {
if (flags & LOOKUP_RCU) {
struct fs_struct *fs = current->fs;
unsigned seq;
}
} else {
/* Caller must check execute permissions on the starting path component */
- struct fd f = fdget_raw(dfd);
+ struct fd f = fdget_raw(nd->dfd);
struct dentry *dentry;
if (!f.file)
- return -EBADF;
+ return ERR_PTR(-EBADF);
dentry = f.file->f_path.dentry;
if (*s) {
if (!d_can_lookup(dentry)) {
fdput(f);
- return -ENOTDIR;
+ return ERR_PTR(-ENOTDIR);
}
}
nd->path = f.file->f_path;
if (flags & LOOKUP_RCU) {
- if (f.flags & FDPUT_FPUT)
- nd->base = f.file;
- nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
rcu_read_lock();
+ nd->inode = nd->path.dentry->d_inode;
+ nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
} else {
path_get(&nd->path);
- fdput(f);
+ nd->inode = nd->path.dentry->d_inode;
}
+ fdput(f);
+ return s;
}
nd->inode = nd->path.dentry->d_inode;
if (!(flags & LOOKUP_RCU))
- goto done;
+ return s;
if (likely(!read_seqcount_retry(&nd->path.dentry->d_seq, nd->seq)))
- goto done;
+ return s;
if (!(nd->flags & LOOKUP_ROOT))
nd->root.mnt = NULL;
rcu_read_unlock();
- return -ECHILD;
-done:
- current->total_link_count = 0;
- return link_path_walk(s, nd);
+ return ERR_PTR(-ECHILD);
}
-static void path_cleanup(struct nameidata *nd)
+static const char *trailing_symlink(struct nameidata *nd)
{
- if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
- path_put(&nd->root);
- nd->root.mnt = NULL;
- }
- if (unlikely(nd->base))
- fput(nd->base);
+ const char *s;
+ int error = may_follow_link(nd);
+ if (unlikely(error))
+ return ERR_PTR(error);
+ nd->flags |= LOOKUP_PARENT;
+ nd->stack[0].name = NULL;
+ s = get_link(nd);
+ return s ? s : "";
}
-static inline int lookup_last(struct nameidata *nd, struct path *path)
+static inline int lookup_last(struct nameidata *nd)
{
if (nd->last_type == LAST_NORM && nd->last.name[nd->last.len])
nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
nd->flags &= ~LOOKUP_PARENT;
- return walk_component(nd, path, nd->flags & LOOKUP_FOLLOW);
+ return walk_component(nd,
+ nd->flags & LOOKUP_FOLLOW
+ ? nd->depth
+ ? WALK_PUT | WALK_GET
+ : WALK_GET
+ : 0);
}
/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
-static int path_lookupat(int dfd, const struct filename *name,
- unsigned int flags, struct nameidata *nd)
+static int path_lookupat(struct nameidata *nd, unsigned flags, struct path *path)
{
- struct path path;
+ const char *s = path_init(nd, flags);
int err;
- /*
- * Path walking is largely split up into 2 different synchronisation
- * schemes, rcu-walk and ref-walk (explained in
- * Documentation/filesystems/path-lookup.txt). These share much of the
- * path walk code, but some things particularly setup, cleanup, and
- * following mounts are sufficiently divergent that functions are
- * duplicated. Typically there is a function foo(), and its RCU
- * analogue, foo_rcu().
- *
- * -ECHILD is the error number of choice (just to avoid clashes) that
- * is returned if some aspect of an rcu-walk fails. Such an error must
- * be handled by restarting a traditional ref-walk (which will always
- * be able to complete).
- */
- err = path_init(dfd, name, flags, nd);
- if (!err && !(flags & LOOKUP_PARENT)) {
- err = lookup_last(nd, &path);
- while (err > 0) {
- void *cookie;
- struct path link = path;
- err = may_follow_link(&link, nd);
- if (unlikely(err))
- break;
- nd->flags |= LOOKUP_PARENT;
- err = follow_link(&link, nd, &cookie);
- if (err)
- break;
- err = lookup_last(nd, &path);
- put_link(nd, &link, cookie);
+ if (IS_ERR(s))
+ return PTR_ERR(s);
+ while (!(err = link_path_walk(s, nd))
+ && ((err = lookup_last(nd)) > 0)) {
+ s = trailing_symlink(nd);
+ if (IS_ERR(s)) {
+ err = PTR_ERR(s);
+ break;
}
}
-
if (!err)
err = complete_walk(nd);
- if (!err && nd->flags & LOOKUP_DIRECTORY) {
- if (!d_can_lookup(nd->path.dentry)) {
- path_put(&nd->path);
+ if (!err && nd->flags & LOOKUP_DIRECTORY)
+ if (!d_can_lookup(nd->path.dentry))
err = -ENOTDIR;
- }
+ if (!err) {
+ *path = nd->path;
+ nd->path.mnt = NULL;
+ nd->path.dentry = NULL;
}
-
- path_cleanup(nd);
+ terminate_walk(nd);
return err;
}
-static int filename_lookup(int dfd, struct filename *name,
- unsigned int flags, struct nameidata *nd)
+static int filename_lookup(int dfd, struct filename *name, unsigned flags,
+ struct path *path, struct path *root)
{
- int retval = path_lookupat(dfd, name, flags | LOOKUP_RCU, nd);
+ int retval;
+ struct nameidata nd;
+ if (IS_ERR(name))
+ return PTR_ERR(name);
+ if (unlikely(root)) {
+ nd.root = *root;
+ flags |= LOOKUP_ROOT;
+ }
+ set_nameidata(&nd, dfd, name);
+ retval = path_lookupat(&nd, flags | LOOKUP_RCU, path);
if (unlikely(retval == -ECHILD))
- retval = path_lookupat(dfd, name, flags, nd);
+ retval = path_lookupat(&nd, flags, path);
if (unlikely(retval == -ESTALE))
- retval = path_lookupat(dfd, name, flags | LOOKUP_REVAL, nd);
+ retval = path_lookupat(&nd, flags | LOOKUP_REVAL, path);
if (likely(!retval))
- audit_inode(name, nd->path.dentry, flags & LOOKUP_PARENT);
+ audit_inode(name, path->dentry, flags & LOOKUP_PARENT);
+ restore_nameidata();
+ putname(name);
return retval;
}
+/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */
+static int path_parentat(struct nameidata *nd, unsigned flags,
+ struct path *parent)
+{
+ const char *s = path_init(nd, flags);
+ int err;
+ if (IS_ERR(s))
+ return PTR_ERR(s);
+ err = link_path_walk(s, nd);
+ if (!err)
+ err = complete_walk(nd);
+ if (!err) {
+ *parent = nd->path;
+ nd->path.mnt = NULL;
+ nd->path.dentry = NULL;
+ }
+ terminate_walk(nd);
+ return err;
+}
+
+static struct filename *filename_parentat(int dfd, struct filename *name,
+ unsigned int flags, struct path *parent,
+ struct qstr *last, int *type)
+{
+ int retval;
+ struct nameidata nd;
+
+ if (IS_ERR(name))
+ return name;
+ set_nameidata(&nd, dfd, name);
+ retval = path_parentat(&nd, flags | LOOKUP_RCU, parent);
+ if (unlikely(retval == -ECHILD))
+ retval = path_parentat(&nd, flags, parent);
+ if (unlikely(retval == -ESTALE))
+ retval = path_parentat(&nd, flags | LOOKUP_REVAL, parent);
+ if (likely(!retval)) {
+ *last = nd.last;
+ *type = nd.last_type;
+ audit_inode(name, parent->dentry, LOOKUP_PARENT);
+ } else {
+ putname(name);
+ name = ERR_PTR(retval);
+ }
+ restore_nameidata();
+ return name;
+}
+
/* does lookup, returns the object with parent locked */
struct dentry *kern_path_locked(const char *name, struct path *path)
{
- struct filename *filename = getname_kernel(name);
- struct nameidata nd;
+ struct filename *filename;
struct dentry *d;
- int err;
+ struct qstr last;
+ int type;
+ filename = filename_parentat(AT_FDCWD, getname_kernel(name), 0, path,
+ &last, &type);
if (IS_ERR(filename))
return ERR_CAST(filename);
-
- err = filename_lookup(AT_FDCWD, filename, LOOKUP_PARENT, &nd);
- if (err) {
- d = ERR_PTR(err);
- goto out;
- }
- if (nd.last_type != LAST_NORM) {
- path_put(&nd.path);
- d = ERR_PTR(-EINVAL);
- goto out;
+ if (unlikely(type != LAST_NORM)) {
+ path_put(path);
+ putname(filename);
+ return ERR_PTR(-EINVAL);
}
- mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
- d = __lookup_hash(&nd.last, nd.path.dentry, 0);
+ mutex_lock_nested(&path->dentry->d_inode->i_mutex, I_MUTEX_PARENT);
+ d = __lookup_hash(&last, path->dentry, 0);
if (IS_ERR(d)) {
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
- path_put(&nd.path);
- goto out;
+ mutex_unlock(&path->dentry->d_inode->i_mutex);
+ path_put(path);
}
- *path = nd.path;
-out:
putname(filename);
return d;
}
int kern_path(const char *name, unsigned int flags, struct path *path)
{
- struct nameidata nd;
- struct filename *filename = getname_kernel(name);
- int res = PTR_ERR(filename);
-
- if (!IS_ERR(filename)) {
- res = filename_lookup(AT_FDCWD, filename, flags, &nd);
- putname(filename);
- if (!res)
- *path = nd.path;
- }
- return res;
+ return filename_lookup(AT_FDCWD, getname_kernel(name),
+ flags, path, NULL);
}
EXPORT_SYMBOL(kern_path);
const char *name, unsigned int flags,
struct path *path)
{
- struct filename *filename = getname_kernel(name);
- int err = PTR_ERR(filename);
-
- BUG_ON(flags & LOOKUP_PARENT);
-
- /* the first argument of filename_lookup() is ignored with LOOKUP_ROOT */
- if (!IS_ERR(filename)) {
- struct nameidata nd;
- nd.root.dentry = dentry;
- nd.root.mnt = mnt;
- err = filename_lookup(AT_FDCWD, filename,
- flags | LOOKUP_ROOT, &nd);
- if (!err)
- *path = nd.path;
- putname(filename);
- }
- return err;
+ struct path root = {.mnt = mnt, .dentry = dentry};
+ /* the first argument of filename_lookup() is ignored with root */
+ return filename_lookup(AT_FDCWD, getname_kernel(name),
+ flags , path, &root);
}
EXPORT_SYMBOL(vfs_path_lookup);
-/*
- * Restricted form of lookup. Doesn't follow links, single-component only,
- * needs parent already locked. Doesn't follow mounts.
- * SMP-safe.
- */
-static struct dentry *lookup_hash(struct nameidata *nd)
-{
- return __lookup_hash(&nd->last, nd->path.dentry, nd->flags);
-}
-
/**
* lookup_one_len - filesystem helper to lookup single pathname component
* @name: pathname component to lookup
int user_path_at_empty(int dfd, const char __user *name, unsigned flags,
struct path *path, int *empty)
{
- struct nameidata nd;
- struct filename *tmp = getname_flags(name, flags, empty);
- int err = PTR_ERR(tmp);
- if (!IS_ERR(tmp)) {
-
- BUG_ON(flags & LOOKUP_PARENT);
-
- err = filename_lookup(dfd, tmp, flags, &nd);
- putname(tmp);
- if (!err)
- *path = nd.path;
- }
- return err;
-}
-
-int user_path_at(int dfd, const char __user *name, unsigned flags,
- struct path *path)
-{
- return user_path_at_empty(dfd, name, flags, path, NULL);
+ return filename_lookup(dfd, getname_flags(name, flags, empty),
+ flags, path, NULL);
}
-EXPORT_SYMBOL(user_path_at);
+EXPORT_SYMBOL(user_path_at_empty);
/*
* NB: most callers don't do anything directly with the reference to the
* allocated by getname. So we must hold the reference to it until all
* path-walking is complete.
*/
-static struct filename *
-user_path_parent(int dfd, const char __user *path, struct nameidata *nd,
+static inline struct filename *
+user_path_parent(int dfd, const char __user *path,
+ struct path *parent,
+ struct qstr *last,
+ int *type,
unsigned int flags)
{
- struct filename *s = getname(path);
- int error;
-
/* only LOOKUP_REVAL is allowed in extra flags */
- flags &= LOOKUP_REVAL;
-
- if (IS_ERR(s))
- return s;
-
- error = filename_lookup(dfd, s, flags | LOOKUP_PARENT, nd);
- if (error) {
- putname(s);
- return ERR_PTR(error);
- }
-
- return s;
+ return filename_parentat(dfd, getname(path), flags & LOOKUP_REVAL,
+ parent, last, type);
}
/**
/* If we're in rcuwalk, drop out of it to handle last component */
if (nd->flags & LOOKUP_RCU) {
- if (unlazy_walk(nd, NULL)) {
- error = -ECHILD;
- goto out;
- }
+ if (unlazy_walk(nd, NULL, 0))
+ return -ECHILD;
}
nd->flags &= ~LOOKUP_PARENT;
if (unlikely(nd->last_type != LAST_NORM)) {
error = handle_dots(nd, nd->last_type);
if (error)
- goto out;
+ return error;
dentry = dget(nd->path.dentry);
goto done;
}
*/
dentry = d_alloc(dir, &nd->last);
if (!dentry) {
- error = -ENOMEM;
mutex_unlock(&dir->d_inode->i_mutex);
- goto out;
+ return -ENOMEM;
}
dentry = lookup_real(dir->d_inode, dentry, nd->flags);
- error = PTR_ERR(dentry);
if (IS_ERR(dentry)) {
mutex_unlock(&dir->d_inode->i_mutex);
- goto out;
+ return PTR_ERR(dentry);
}
}
mutex_unlock(&dir->d_inode->i_mutex);
done:
if (d_is_negative(dentry)) {
- error = -ENOENT;
dput(dentry);
- goto out;
+ return -ENOENT;
}
+ if (nd->depth)
+ put_link(nd);
path->dentry = dentry;
path->mnt = nd->path.mnt;
- if (should_follow_link(dentry, nd->flags & LOOKUP_FOLLOW))
- return 1;
+ error = should_follow_link(nd, path, nd->flags & LOOKUP_FOLLOW,
+ d_backing_inode(dentry), 0);
+ if (unlikely(error))
+ return error;
mntget(path->mnt);
follow_mount(path);
- error = 0;
-out:
- terminate_walk(nd);
- return error;
+ return 0;
}
/**
* path_mountpoint - look up a path to be umounted
- * @dfd: directory file descriptor to start walk from
- * @name: full pathname to walk
- * @path: pointer to container for result
+ * @nameidata: lookup context
* @flags: lookup flags
+ * @path: pointer to container for result
*
* Look up the given name, but don't attempt to revalidate the last component.
* Returns 0 and "path" will be valid on success; Returns error otherwise.
*/
static int
-path_mountpoint(int dfd, const struct filename *name, struct path *path,
- unsigned int flags)
+path_mountpoint(struct nameidata *nd, unsigned flags, struct path *path)
{
- struct nameidata nd;
+ const char *s = path_init(nd, flags);
int err;
-
- err = path_init(dfd, name, flags, &nd);
- if (unlikely(err))
- goto out;
-
- err = mountpoint_last(&nd, path);
- while (err > 0) {
- void *cookie;
- struct path link = *path;
- err = may_follow_link(&link, &nd);
- if (unlikely(err))
- break;
- nd.flags |= LOOKUP_PARENT;
- err = follow_link(&link, &nd, &cookie);
- if (err)
+ if (IS_ERR(s))
+ return PTR_ERR(s);
+ while (!(err = link_path_walk(s, nd)) &&
+ (err = mountpoint_last(nd, path)) > 0) {
+ s = trailing_symlink(nd);
+ if (IS_ERR(s)) {
+ err = PTR_ERR(s);
break;
- err = mountpoint_last(&nd, path);
- put_link(&nd, &link, cookie);
+ }
}
-out:
- path_cleanup(&nd);
+ terminate_walk(nd);
return err;
}
filename_mountpoint(int dfd, struct filename *name, struct path *path,
unsigned int flags)
{
+ struct nameidata nd;
int error;
if (IS_ERR(name))
return PTR_ERR(name);
- error = path_mountpoint(dfd, name, path, flags | LOOKUP_RCU);
+ set_nameidata(&nd, dfd, name);
+ error = path_mountpoint(&nd, flags | LOOKUP_RCU, path);
if (unlikely(error == -ECHILD))
- error = path_mountpoint(dfd, name, path, flags);
+ error = path_mountpoint(&nd, flags, path);
if (unlikely(error == -ESTALE))
- error = path_mountpoint(dfd, name, path, flags | LOOKUP_REVAL);
+ error = path_mountpoint(&nd, flags | LOOKUP_REVAL, path);
if (likely(!error))
audit_inode(name, path->dentry, 0);
+ restore_nameidata();
putname(name);
return error;
}
*/
static int may_delete(struct inode *dir, struct dentry *victim, bool isdir)
{
- struct inode *inode = victim->d_inode;
+ struct inode *inode = d_backing_inode(victim);
int error;
if (d_is_negative(victim))
/*
* Handle the last step of open()
*/
-static int do_last(struct nameidata *nd, struct path *path,
+static int do_last(struct nameidata *nd,
struct file *file, const struct open_flags *op,
- int *opened, struct filename *name)
+ int *opened)
{
struct dentry *dir = nd->path.dentry;
int open_flag = op->open_flag;
bool will_truncate = (open_flag & O_TRUNC) != 0;
bool got_write = false;
int acc_mode = op->acc_mode;
+ unsigned seq;
struct inode *inode;
- bool symlink_ok = false;
struct path save_parent = { .dentry = NULL, .mnt = NULL };
+ struct path path;
bool retried = false;
int error;
if (nd->last_type != LAST_NORM) {
error = handle_dots(nd, nd->last_type);
- if (error)
+ if (unlikely(error))
return error;
goto finish_open;
}
if (!(open_flag & O_CREAT)) {
if (nd->last.name[nd->last.len])
nd->flags |= LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
- if (open_flag & O_PATH && !(nd->flags & LOOKUP_FOLLOW))
- symlink_ok = true;
/* we _can_ be in RCU mode here */
- error = lookup_fast(nd, path, &inode);
+ error = lookup_fast(nd, &path, &inode, &seq);
if (likely(!error))
goto finish_lookup;
if (error < 0)
- goto out;
+ return error;
BUG_ON(nd->inode != dir->d_inode);
} else {
if (error)
return error;
- audit_inode(name, dir, LOOKUP_PARENT);
- error = -EISDIR;
+ audit_inode(nd->name, dir, LOOKUP_PARENT);
/* trailing slashes? */
- if (nd->last.name[nd->last.len])
- goto out;
+ if (unlikely(nd->last.name[nd->last.len]))
+ return -EISDIR;
}
retry_lookup:
*/
}
mutex_lock(&dir->d_inode->i_mutex);
- error = lookup_open(nd, path, file, op, got_write, opened);
+ error = lookup_open(nd, &path, file, op, got_write, opened);
mutex_unlock(&dir->d_inode->i_mutex);
if (error <= 0) {
!S_ISREG(file_inode(file)->i_mode))
will_truncate = false;
- audit_inode(name, file->f_path.dentry, 0);
+ audit_inode(nd->name, file->f_path.dentry, 0);
goto opened;
}
open_flag &= ~O_TRUNC;
will_truncate = false;
acc_mode = MAY_OPEN;
- path_to_nameidata(path, nd);
+ path_to_nameidata(&path, nd);
goto finish_open_created;
}
/*
* create/update audit record if it already exists.
*/
- if (d_is_positive(path->dentry))
- audit_inode(name, path->dentry, 0);
+ if (d_is_positive(path.dentry))
+ audit_inode(nd->name, path.dentry, 0);
/*
* If atomic_open() acquired write access it is dropped now due to
got_write = false;
}
- error = -EEXIST;
- if ((open_flag & (O_EXCL | O_CREAT)) == (O_EXCL | O_CREAT))
- goto exit_dput;
-
- error = follow_managed(path, nd->flags);
- if (error < 0)
- goto exit_dput;
+ if (unlikely((open_flag & (O_EXCL | O_CREAT)) == (O_EXCL | O_CREAT))) {
+ path_to_nameidata(&path, nd);
+ return -EEXIST;
+ }
- if (error)
- nd->flags |= LOOKUP_JUMPED;
+ error = follow_managed(&path, nd);
+ if (unlikely(error < 0))
+ return error;
BUG_ON(nd->flags & LOOKUP_RCU);
- inode = path->dentry->d_inode;
- error = -ENOENT;
- if (d_is_negative(path->dentry)) {
- path_to_nameidata(path, nd);
- goto out;
+ inode = d_backing_inode(path.dentry);
+ seq = 0; /* out of RCU mode, so the value doesn't matter */
+ if (unlikely(d_is_negative(path.dentry))) {
+ path_to_nameidata(&path, nd);
+ return -ENOENT;
}
finish_lookup:
- /* we _can_ be in RCU mode here */
- if (should_follow_link(path->dentry, !symlink_ok)) {
- if (nd->flags & LOOKUP_RCU) {
- if (unlikely(nd->path.mnt != path->mnt ||
- unlazy_walk(nd, path->dentry))) {
- error = -ECHILD;
- goto out;
- }
- }
- BUG_ON(inode != path->dentry->d_inode);
- return 1;
+ if (nd->depth)
+ put_link(nd);
+ error = should_follow_link(nd, &path, nd->flags & LOOKUP_FOLLOW,
+ inode, seq);
+ if (unlikely(error))
+ return error;
+
+ if (unlikely(d_is_symlink(path.dentry)) && !(open_flag & O_PATH)) {
+ path_to_nameidata(&path, nd);
+ return -ELOOP;
}
- if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path->mnt) {
- path_to_nameidata(path, nd);
+ if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path.mnt) {
+ path_to_nameidata(&path, nd);
} else {
save_parent.dentry = nd->path.dentry;
- save_parent.mnt = mntget(path->mnt);
- nd->path.dentry = path->dentry;
+ save_parent.mnt = mntget(path.mnt);
+ nd->path.dentry = path.dentry;
}
nd->inode = inode;
+ nd->seq = seq;
/* Why this, you ask? _Now_ we might have grown LOOKUP_JUMPED... */
finish_open:
error = complete_walk(nd);
path_put(&save_parent);
return error;
}
- audit_inode(name, nd->path.dentry, 0);
+ audit_inode(nd->name, nd->path.dentry, 0);
error = -EISDIR;
if ((open_flag & O_CREAT) && d_is_dir(nd->path.dentry))
goto out;
if (got_write)
mnt_drop_write(nd->path.mnt);
path_put(&save_parent);
- terminate_walk(nd);
return error;
-exit_dput:
- path_put_conditional(path, nd);
- goto out;
exit_fput:
fput(file);
goto out;
goto retry_lookup;
}
-static int do_tmpfile(int dfd, struct filename *pathname,
- struct nameidata *nd, int flags,
+static int do_tmpfile(struct nameidata *nd, unsigned flags,
const struct open_flags *op,
struct file *file, int *opened)
{
static const struct qstr name = QSTR_INIT("/", 1);
- struct dentry *dentry, *child;
+ struct dentry *child;
struct inode *dir;
- int error = path_lookupat(dfd, pathname,
- flags | LOOKUP_DIRECTORY, nd);
+ struct path path;
+ int error = path_lookupat(nd, flags | LOOKUP_DIRECTORY, &path);
if (unlikely(error))
return error;
- error = mnt_want_write(nd->path.mnt);
+ error = mnt_want_write(path.mnt);
if (unlikely(error))
goto out;
+ dir = path.dentry->d_inode;
/* we want directory to be writable */
- error = inode_permission(nd->inode, MAY_WRITE | MAY_EXEC);
+ error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
if (error)
goto out2;
- dentry = nd->path.dentry;
- dir = dentry->d_inode;
if (!dir->i_op->tmpfile) {
error = -EOPNOTSUPP;
goto out2;
}
- child = d_alloc(dentry, &name);
+ child = d_alloc(path.dentry, &name);
if (unlikely(!child)) {
error = -ENOMEM;
goto out2;
}
- nd->flags &= ~LOOKUP_DIRECTORY;
- nd->flags |= op->intent;
- dput(nd->path.dentry);
- nd->path.dentry = child;
- error = dir->i_op->tmpfile(dir, nd->path.dentry, op->mode);
+ dput(path.dentry);
+ path.dentry = child;
+ error = dir->i_op->tmpfile(dir, child, op->mode);
if (error)
goto out2;
- audit_inode(pathname, nd->path.dentry, 0);
+ audit_inode(nd->name, child, 0);
/* Don't check for other permissions, the inode was just created */
- error = may_open(&nd->path, MAY_OPEN, op->open_flag);
+ error = may_open(&path, MAY_OPEN, op->open_flag);
if (error)
goto out2;
- file->f_path.mnt = nd->path.mnt;
- error = finish_open(file, nd->path.dentry, NULL, opened);
+ file->f_path.mnt = path.mnt;
+ error = finish_open(file, child, NULL, opened);
if (error)
goto out2;
error = open_check_o_direct(file);
spin_unlock(&inode->i_lock);
}
out2:
- mnt_drop_write(nd->path.mnt);
+ mnt_drop_write(path.mnt);
out:
- path_put(&nd->path);
+ path_put(&path);
return error;
}
-static struct file *path_openat(int dfd, struct filename *pathname,
- struct nameidata *nd, const struct open_flags *op, int flags)
+static struct file *path_openat(struct nameidata *nd,
+ const struct open_flags *op, unsigned flags)
{
+ const char *s;
struct file *file;
- struct path path;
int opened = 0;
int error;
file->f_flags = op->open_flag;
if (unlikely(file->f_flags & __O_TMPFILE)) {
- error = do_tmpfile(dfd, pathname, nd, flags, op, file, &opened);
+ error = do_tmpfile(nd, flags, op, file, &opened);
goto out2;
}
- error = path_init(dfd, pathname, flags, nd);
- if (unlikely(error))
- goto out;
-
- error = do_last(nd, &path, file, op, &opened, pathname);
- while (unlikely(error > 0)) { /* trailing symlink */
- struct path link = path;
- void *cookie;
- if (!(nd->flags & LOOKUP_FOLLOW)) {
- path_put_conditional(&path, nd);
- path_put(&nd->path);
- error = -ELOOP;
- break;
- }
- error = may_follow_link(&link, nd);
- if (unlikely(error))
- break;
- nd->flags |= LOOKUP_PARENT;
+ s = path_init(nd, flags);
+ if (IS_ERR(s)) {
+ put_filp(file);
+ return ERR_CAST(s);
+ }
+ while (!(error = link_path_walk(s, nd)) &&
+ (error = do_last(nd, file, op, &opened)) > 0) {
nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
- error = follow_link(&link, nd, &cookie);
- if (unlikely(error))
+ s = trailing_symlink(nd);
+ if (IS_ERR(s)) {
+ error = PTR_ERR(s);
break;
- error = do_last(nd, &path, file, op, &opened, pathname);
- put_link(nd, &link, cookie);
+ }
}
-out:
- path_cleanup(nd);
+ terminate_walk(nd);
out2:
if (!(opened & FILE_OPENED)) {
BUG_ON(!error);
int flags = op->lookup_flags;
struct file *filp;
- filp = path_openat(dfd, pathname, &nd, op, flags | LOOKUP_RCU);
+ set_nameidata(&nd, dfd, pathname);
+ filp = path_openat(&nd, op, flags | LOOKUP_RCU);
if (unlikely(filp == ERR_PTR(-ECHILD)))
- filp = path_openat(dfd, pathname, &nd, op, flags);
+ filp = path_openat(&nd, op, flags);
if (unlikely(filp == ERR_PTR(-ESTALE)))
- filp = path_openat(dfd, pathname, &nd, op, flags | LOOKUP_REVAL);
+ filp = path_openat(&nd, op, flags | LOOKUP_REVAL);
+ restore_nameidata();
return filp;
}
if (unlikely(IS_ERR(filename)))
return ERR_CAST(filename);
- file = path_openat(-1, filename, &nd, op, flags | LOOKUP_RCU);
+ set_nameidata(&nd, -1, filename);
+ file = path_openat(&nd, op, flags | LOOKUP_RCU);
if (unlikely(file == ERR_PTR(-ECHILD)))
- file = path_openat(-1, filename, &nd, op, flags);
+ file = path_openat(&nd, op, flags);
if (unlikely(file == ERR_PTR(-ESTALE)))
- file = path_openat(-1, filename, &nd, op, flags | LOOKUP_REVAL);
+ file = path_openat(&nd, op, flags | LOOKUP_REVAL);
+ restore_nameidata();
putname(filename);
return file;
}
struct path *path, unsigned int lookup_flags)
{
struct dentry *dentry = ERR_PTR(-EEXIST);
- struct nameidata nd;
+ struct qstr last;
+ int type;
int err2;
int error;
bool is_dir = (lookup_flags & LOOKUP_DIRECTORY);
*/
lookup_flags &= LOOKUP_REVAL;
- error = filename_lookup(dfd, name, LOOKUP_PARENT|lookup_flags, &nd);
- if (error)
- return ERR_PTR(error);
+ name = filename_parentat(dfd, name, lookup_flags, path, &last, &type);
+ if (IS_ERR(name))
+ return ERR_CAST(name);
/*
* Yucky last component or no last component at all?
* (foo/., foo/.., /////)
*/
- if (nd.last_type != LAST_NORM)
+ if (unlikely(type != LAST_NORM))
goto out;
- nd.flags &= ~LOOKUP_PARENT;
- nd.flags |= LOOKUP_CREATE | LOOKUP_EXCL;
/* don't fail immediately if it's r/o, at least try to report other errors */
- err2 = mnt_want_write(nd.path.mnt);
+ err2 = mnt_want_write(path->mnt);
/*
* Do the final lookup.
*/
- mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
- dentry = lookup_hash(&nd);
+ lookup_flags |= LOOKUP_CREATE | LOOKUP_EXCL;
+ mutex_lock_nested(&path->dentry->d_inode->i_mutex, I_MUTEX_PARENT);
+ dentry = __lookup_hash(&last, path->dentry, lookup_flags);
if (IS_ERR(dentry))
goto unlock;
* all is fine. Let's be bastards - you had / on the end, you've
* been asking for (non-existent) directory. -ENOENT for you.
*/
- if (unlikely(!is_dir && nd.last.name[nd.last.len])) {
+ if (unlikely(!is_dir && last.name[last.len])) {
error = -ENOENT;
goto fail;
}
error = err2;
goto fail;
}
- *path = nd.path;
+ putname(name);
return dentry;
fail:
dput(dentry);
dentry = ERR_PTR(error);
unlock:
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+ mutex_unlock(&path->dentry->d_inode->i_mutex);
if (!err2)
- mnt_drop_write(nd.path.mnt);
+ mnt_drop_write(path->mnt);
out:
- path_put(&nd.path);
+ path_put(path);
+ putname(name);
return dentry;
}
struct dentry *kern_path_create(int dfd, const char *pathname,
struct path *path, unsigned int lookup_flags)
{
- struct filename *filename = getname_kernel(pathname);
- struct dentry *res;
-
- if (IS_ERR(filename))
- return ERR_CAST(filename);
- res = filename_create(dfd, filename, path, lookup_flags);
- putname(filename);
- return res;
+ return filename_create(dfd, getname_kernel(pathname),
+ path, lookup_flags);
}
EXPORT_SYMBOL(kern_path_create);
}
EXPORT_SYMBOL(done_path_create);
-struct dentry *user_path_create(int dfd, const char __user *pathname,
+inline struct dentry *user_path_create(int dfd, const char __user *pathname,
struct path *path, unsigned int lookup_flags)
{
- struct filename *tmp = getname(pathname);
- struct dentry *res;
- if (IS_ERR(tmp))
- return ERR_CAST(tmp);
- res = filename_create(dfd, tmp, path, lookup_flags);
- putname(tmp);
- return res;
+ return filename_create(dfd, getname(pathname), path, lookup_flags);
}
EXPORT_SYMBOL(user_path_create);
int error = 0;
struct filename *name;
struct dentry *dentry;
- struct nameidata nd;
+ struct path path;
+ struct qstr last;
+ int type;
unsigned int lookup_flags = 0;
retry:
- name = user_path_parent(dfd, pathname, &nd, lookup_flags);
+ name = user_path_parent(dfd, pathname,
+ &path, &last, &type, lookup_flags);
if (IS_ERR(name))
return PTR_ERR(name);
- switch(nd.last_type) {
+ switch (type) {
case LAST_DOTDOT:
error = -ENOTEMPTY;
goto exit1;
goto exit1;
}
- nd.flags &= ~LOOKUP_PARENT;
- error = mnt_want_write(nd.path.mnt);
+ error = mnt_want_write(path.mnt);
if (error)
goto exit1;
- mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
- dentry = lookup_hash(&nd);
+ mutex_lock_nested(&path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
+ dentry = __lookup_hash(&last, path.dentry, lookup_flags);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto exit2;
error = -ENOENT;
goto exit3;
}
- error = security_path_rmdir(&nd.path, dentry);
+ error = security_path_rmdir(&path, dentry);
if (error)
goto exit3;
- error = vfs_rmdir(nd.path.dentry->d_inode, dentry);
+ error = vfs_rmdir(path.dentry->d_inode, dentry);
exit3:
dput(dentry);
exit2:
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
- mnt_drop_write(nd.path.mnt);
+ mutex_unlock(&path.dentry->d_inode->i_mutex);
+ mnt_drop_write(path.mnt);
exit1:
- path_put(&nd.path);
+ path_put(&path);
putname(name);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
int error;
struct filename *name;
struct dentry *dentry;
- struct nameidata nd;
+ struct path path;
+ struct qstr last;
+ int type;
struct inode *inode = NULL;
struct inode *delegated_inode = NULL;
unsigned int lookup_flags = 0;
retry:
- name = user_path_parent(dfd, pathname, &nd, lookup_flags);
+ name = user_path_parent(dfd, pathname,
+ &path, &last, &type, lookup_flags);
if (IS_ERR(name))
return PTR_ERR(name);
error = -EISDIR;
- if (nd.last_type != LAST_NORM)
+ if (type != LAST_NORM)
goto exit1;
- nd.flags &= ~LOOKUP_PARENT;
- error = mnt_want_write(nd.path.mnt);
+ error = mnt_want_write(path.mnt);
if (error)
goto exit1;
retry_deleg:
- mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
- dentry = lookup_hash(&nd);
+ mutex_lock_nested(&path.dentry->d_inode->i_mutex, I_MUTEX_PARENT);
+ dentry = __lookup_hash(&last, path.dentry, lookup_flags);
error = PTR_ERR(dentry);
if (!IS_ERR(dentry)) {
/* Why not before? Because we want correct error value */
- if (nd.last.name[nd.last.len])
+ if (last.name[last.len])
goto slashes;
inode = dentry->d_inode;
if (d_is_negative(dentry))
goto slashes;
ihold(inode);
- error = security_path_unlink(&nd.path, dentry);
+ error = security_path_unlink(&path, dentry);
if (error)
goto exit2;
- error = vfs_unlink(nd.path.dentry->d_inode, dentry, &delegated_inode);
+ error = vfs_unlink(path.dentry->d_inode, dentry, &delegated_inode);
exit2:
dput(dentry);
}
- mutex_unlock(&nd.path.dentry->d_inode->i_mutex);
+ mutex_unlock(&path.dentry->d_inode->i_mutex);
if (inode)
iput(inode); /* truncate the inode here */
inode = NULL;
if (!error)
goto retry_deleg;
}
- mnt_drop_write(nd.path.mnt);
+ mnt_drop_write(path.mnt);
exit1:
- path_put(&nd.path);
+ path_put(&path);
putname(name);
if (retry_estale(error, lookup_flags)) {
lookup_flags |= LOOKUP_REVAL;
SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname,
int, newdfd, const char __user *, newname, unsigned int, flags)
{
- struct dentry *old_dir, *new_dir;
struct dentry *old_dentry, *new_dentry;
struct dentry *trap;
- struct nameidata oldnd, newnd;
+ struct path old_path, new_path;
+ struct qstr old_last, new_last;
+ int old_type, new_type;
struct inode *delegated_inode = NULL;
struct filename *from;
struct filename *to;
- unsigned int lookup_flags = 0;
+ unsigned int lookup_flags = 0, target_flags = LOOKUP_RENAME_TARGET;
bool should_retry = false;
int error;
if ((flags & RENAME_WHITEOUT) && !capable(CAP_MKNOD))
return -EPERM;
+ if (flags & RENAME_EXCHANGE)
+ target_flags = 0;
+
retry:
- from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags);
+ from = user_path_parent(olddfd, oldname,
+ &old_path, &old_last, &old_type, lookup_flags);
if (IS_ERR(from)) {
error = PTR_ERR(from);
goto exit;
}
- to = user_path_parent(newdfd, newname, &newnd, lookup_flags);
+ to = user_path_parent(newdfd, newname,
+ &new_path, &new_last, &new_type, lookup_flags);
if (IS_ERR(to)) {
error = PTR_ERR(to);
goto exit1;
}
error = -EXDEV;
- if (oldnd.path.mnt != newnd.path.mnt)
+ if (old_path.mnt != new_path.mnt)
goto exit2;
- old_dir = oldnd.path.dentry;
error = -EBUSY;
- if (oldnd.last_type != LAST_NORM)
+ if (old_type != LAST_NORM)
goto exit2;
- new_dir = newnd.path.dentry;
if (flags & RENAME_NOREPLACE)
error = -EEXIST;
- if (newnd.last_type != LAST_NORM)
+ if (new_type != LAST_NORM)
goto exit2;
- error = mnt_want_write(oldnd.path.mnt);
+ error = mnt_want_write(old_path.mnt);
if (error)
goto exit2;
- oldnd.flags &= ~LOOKUP_PARENT;
- newnd.flags &= ~LOOKUP_PARENT;
- if (!(flags & RENAME_EXCHANGE))
- newnd.flags |= LOOKUP_RENAME_TARGET;
-
retry_deleg:
- trap = lock_rename(new_dir, old_dir);
+ trap = lock_rename(new_path.dentry, old_path.dentry);
- old_dentry = lookup_hash(&oldnd);
+ old_dentry = __lookup_hash(&old_last, old_path.dentry, lookup_flags);
error = PTR_ERR(old_dentry);
if (IS_ERR(old_dentry))
goto exit3;
error = -ENOENT;
if (d_is_negative(old_dentry))
goto exit4;
- new_dentry = lookup_hash(&newnd);
+ new_dentry = __lookup_hash(&new_last, new_path.dentry, lookup_flags | target_flags);
error = PTR_ERR(new_dentry);
if (IS_ERR(new_dentry))
goto exit4;
if (!d_is_dir(new_dentry)) {
error = -ENOTDIR;
- if (newnd.last.name[newnd.last.len])
+ if (new_last.name[new_last.len])
goto exit5;
}
}
/* unless the source is a directory trailing slashes give -ENOTDIR */
if (!d_is_dir(old_dentry)) {
error = -ENOTDIR;
- if (oldnd.last.name[oldnd.last.len])
+ if (old_last.name[old_last.len])
goto exit5;
- if (!(flags & RENAME_EXCHANGE) && newnd.last.name[newnd.last.len])
+ if (!(flags & RENAME_EXCHANGE) && new_last.name[new_last.len])
goto exit5;
}
/* source should not be ancestor of target */
if (new_dentry == trap)
goto exit5;
- error = security_path_rename(&oldnd.path, old_dentry,
- &newnd.path, new_dentry, flags);
+ error = security_path_rename(&old_path, old_dentry,
+ &new_path, new_dentry, flags);
if (error)
goto exit5;
- error = vfs_rename(old_dir->d_inode, old_dentry,
- new_dir->d_inode, new_dentry,
+ error = vfs_rename(old_path.dentry->d_inode, old_dentry,
+ new_path.dentry->d_inode, new_dentry,
&delegated_inode, flags);
exit5:
dput(new_dentry);
exit4:
dput(old_dentry);
exit3:
- unlock_rename(new_dir, old_dir);
+ unlock_rename(new_path.dentry, old_path.dentry);
if (delegated_inode) {
error = break_deleg_wait(&delegated_inode);
if (!error)
goto retry_deleg;
}
- mnt_drop_write(oldnd.path.mnt);
+ mnt_drop_write(old_path.mnt);
exit2:
if (retry_estale(error, lookup_flags))
should_retry = true;
- path_put(&newnd.path);
+ path_put(&new_path);
putname(to);
exit1:
- path_put(&oldnd.path);
+ path_put(&old_path);
putname(from);
if (should_retry) {
should_retry = false;
*/
int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen)
{
- struct nameidata nd;
void *cookie;
+ struct inode *inode = d_inode(dentry);
+ const char *link = inode->i_link;
int res;
- nd.depth = 0;
- cookie = dentry->d_inode->i_op->follow_link(dentry, &nd);
- if (IS_ERR(cookie))
- return PTR_ERR(cookie);
-
- res = readlink_copy(buffer, buflen, nd_get_link(&nd));
- if (dentry->d_inode->i_op->put_link)
- dentry->d_inode->i_op->put_link(dentry, &nd, cookie);
+ if (!link) {
+ link = inode->i_op->follow_link(dentry, &cookie);
+ if (IS_ERR(link))
+ return PTR_ERR(link);
+ }
+ res = readlink_copy(buffer, buflen, link);
+ if (inode->i_op->put_link)
+ inode->i_op->put_link(inode, cookie);
return res;
}
EXPORT_SYMBOL(generic_readlink);
}
EXPORT_SYMBOL(page_readlink);
-void *page_follow_link_light(struct dentry *dentry, struct nameidata *nd)
+const char *page_follow_link_light(struct dentry *dentry, void **cookie)
{
struct page *page = NULL;
- nd_set_link(nd, page_getlink(dentry, &page));
- return page;
+ char *res = page_getlink(dentry, &page);
+ if (!IS_ERR(res))
+ *cookie = page;
+ return res;
}
EXPORT_SYMBOL(page_follow_link_light);
-void page_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
+void page_put_link(struct inode *unused, void *cookie)
{
struct page *page = cookie;
-
- if (page) {
- kunmap(page);
- page_cache_release(page);
- }
+ kunmap(page);
+ page_cache_release(page);
}
EXPORT_SYMBOL(page_put_link);
}
/* call under rcu_read_lock */
-bool legitimize_mnt(struct vfsmount *bastard, unsigned seq)
+int __legitimize_mnt(struct vfsmount *bastard, unsigned seq)
{
struct mount *mnt;
if (read_seqretry(&mount_lock, seq))
- return false;
+ return 1;
if (bastard == NULL)
- return true;
+ return 0;
mnt = real_mount(bastard);
mnt_add_count(mnt, 1);
if (likely(!read_seqretry(&mount_lock, seq)))
- return true;
+ return 0;
if (bastard->mnt_flags & MNT_SYNC_UMOUNT) {
mnt_add_count(mnt, -1);
- return false;
+ return 1;
+ }
+ return -1;
+}
+
+/* call under rcu_read_lock */
+bool legitimize_mnt(struct vfsmount *bastard, unsigned seq)
+{
+ int res = __legitimize_mnt(bastard, seq);
+ if (likely(!res))
+ return true;
+ if (unlikely(res < 0)) {
+ rcu_read_unlock();
+ mntput(bastard);
+ rcu_read_lock();
}
- rcu_read_unlock();
- mntput(bastard);
- rcu_read_lock();
return false;
}
#include <linux/stat.h>
#include <linux/mm.h>
#include <linux/string.h>
-#include <linux/namei.h>
/* Symlink caching in the page cache is even more simplistic
* and straight-forward than readdir caching.
return -EIO;
}
-static void *nfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *nfs_follow_link(struct dentry *dentry, void **cookie)
{
struct inode *inode = d_inode(dentry);
struct page *page;
err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));
if (err)
- goto read_failed;
+ return err;
page = read_cache_page(&inode->i_data, 0,
(filler_t *)nfs_symlink_filler, inode);
- if (IS_ERR(page)) {
- err = page;
- goto read_failed;
- }
- nd_set_link(nd, kmap(page));
- return page;
-
-read_failed:
- nd_set_link(nd, err);
- return NULL;
+ if (IS_ERR(page))
+ return ERR_CAST(page);
+ *cookie = page;
+ return kmap(page);
}
/*
* ntfs_lookup - find the inode represented by a dentry in a directory inode
* @dir_ino: directory inode in which to look for the inode
* @dent: dentry representing the inode to look for
- * @nd: lookup nameidata
+ * @flags: lookup flags
*
* In short, ntfs_lookup() looks for the inode represented by the dentry @dent
* in the directory inode @dir_ino and if found attaches the inode to the
if (res)
goto out;
- inode = path.dentry->d_inode;
+ inode = d_backing_inode(path.dentry);
if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) {
/*
void *cookie;
};
-static void *ovl_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *ovl_follow_link(struct dentry *dentry, void **cookie)
{
- void *ret;
struct dentry *realdentry;
struct inode *realinode;
+ struct ovl_link_data *data = NULL;
+ const char *ret;
realdentry = ovl_dentry_real(dentry);
realinode = realdentry->d_inode;
if (WARN_ON(!realinode->i_op->follow_link))
return ERR_PTR(-EPERM);
- ret = realinode->i_op->follow_link(realdentry, nd);
- if (IS_ERR(ret))
- return ret;
-
if (realinode->i_op->put_link) {
- struct ovl_link_data *data;
-
data = kmalloc(sizeof(struct ovl_link_data), GFP_KERNEL);
- if (!data) {
- realinode->i_op->put_link(realdentry, nd, ret);
+ if (!data)
return ERR_PTR(-ENOMEM);
- }
data->realdentry = realdentry;
- data->cookie = ret;
+ }
- return data;
- } else {
- return NULL;
+ ret = realinode->i_op->follow_link(realdentry, cookie);
+ if (IS_ERR_OR_NULL(ret)) {
+ kfree(data);
+ return ret;
}
+
+ if (data)
+ data->cookie = *cookie;
+
+ *cookie = data;
+
+ return ret;
}
-static void ovl_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
+static void ovl_put_link(struct inode *unused, void *c)
{
struct inode *realinode;
struct ovl_link_data *data = c;
return;
realinode = data->realdentry->d_inode;
- realinode->i_op->put_link(data->realdentry, nd, data->cookie);
+ realinode->i_op->put_link(realinode, data->cookie);
kfree(data);
}
return -ENOENT;
}
-static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *proc_pid_follow_link(struct dentry *dentry, void **cookie)
{
struct inode *inode = d_inode(dentry);
struct path path;
if (error)
goto out;
- nd_jump_link(nd, &path);
+ nd_jump_link(&path);
return NULL;
out:
return ERR_PTR(error);
#include <linux/slab.h>
#include <linux/mount.h>
#include <linux/magic.h>
-#include <linux/namei.h>
#include <asm/uaccess.h>
};
#endif
-static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *proc_follow_link(struct dentry *dentry, void **cookie)
{
struct proc_dir_entry *pde = PDE(d_inode(dentry));
if (unlikely(!use_pde(pde)))
return ERR_PTR(-EINVAL);
- nd_set_link(nd, pde->data);
- return pde;
+ *cookie = pde;
+ return pde->data;
}
-static void proc_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
+static void proc_put_link(struct inode *unused, void *p)
{
unuse_pde(p);
}
&mntns_operations,
};
-static void *proc_ns_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *proc_ns_follow_link(struct dentry *dentry, void **cookie)
{
struct inode *inode = d_inode(dentry);
const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
if (ptrace_may_access(task, PTRACE_MODE_READ)) {
error = ns_get_path(&ns_path, task, ns_ops);
if (!error)
- nd_jump_link(nd, &ns_path);
+ nd_jump_link(&ns_path);
}
put_task_struct(task);
return error;
#include <linux/sched.h>
-#include <linux/namei.h>
#include <linux/slab.h>
#include <linux/pid_namespace.h>
#include "internal.h"
return readlink_copy(buffer, buflen, tmp);
}
-static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *proc_self_follow_link(struct dentry *dentry, void **cookie)
{
struct pid_namespace *ns = dentry->d_sb->s_fs_info;
pid_t tgid = task_tgid_nr_ns(current, ns);
- char *name = ERR_PTR(-ENOENT);
- if (tgid) {
- /* 11 for max length of signed int in decimal + NULL term */
- name = kmalloc(12, GFP_KERNEL);
- if (!name)
- name = ERR_PTR(-ENOMEM);
- else
- sprintf(name, "%d", tgid);
- }
- nd_set_link(nd, name);
- return NULL;
+ char *name;
+
+ if (!tgid)
+ return ERR_PTR(-ENOENT);
+ /* 11 for max length of signed int in decimal + NULL term */
+ name = kmalloc(12, GFP_KERNEL);
+ if (!name)
+ return ERR_PTR(-ENOMEM);
+ sprintf(name, "%d", tgid);
+ return *cookie = name;
}
static const struct inode_operations proc_self_inode_operations = {
#include <linux/sched.h>
-#include <linux/namei.h>
#include <linux/slab.h>
#include <linux/pid_namespace.h>
#include "internal.h"
return readlink_copy(buffer, buflen, tmp);
}
-static void *proc_thread_self_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *proc_thread_self_follow_link(struct dentry *dentry, void **cookie)
{
struct pid_namespace *ns = dentry->d_sb->s_fs_info;
pid_t tgid = task_tgid_nr_ns(current, ns);
pid_t pid = task_pid_nr_ns(current, ns);
- char *name = ERR_PTR(-ENOENT);
- if (pid) {
- name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF, GFP_KERNEL);
- if (!name)
- name = ERR_PTR(-ENOMEM);
- else
- sprintf(name, "%d/task/%d", tgid, pid);
- }
- nd_set_link(nd, name);
- return NULL;
+ char *name;
+
+ if (!pid)
+ return ERR_PTR(-ENOENT);
+ name = kmalloc(PROC_NUMBUF + 6 + PROC_NUMBUF, GFP_KERNEL);
+ if (!name)
+ return ERR_PTR(-ENOMEM);
+ sprintf(name, "%d/task/%d", tgid, pid);
+ return *cookie = name;
}
static const struct inode_operations proc_thread_self_inode_operations = {
obj-$(CONFIG_SYSV_FS) += sysv.o
sysv-objs := ialloc.o balloc.o inode.o itree.o file.o dir.o \
- namei.o super.o symlink.o
+ namei.o super.o
inode->i_op = &sysv_symlink_inode_operations;
inode->i_mapping->a_ops = &sysv_aops;
} else {
- inode->i_op = &sysv_fast_symlink_inode_operations;
- nd_terminate_link(SYSV_I(inode)->i_data, inode->i_size,
+ inode->i_op = &simple_symlink_inode_operations;
+ inode->i_link = (char *)SYSV_I(inode)->i_data;
+ nd_terminate_link(inode->i_link, inode->i_size,
sizeof(SYSV_I(inode)->i_data) - 1);
}
} else
+++ /dev/null
-/*
- * linux/fs/sysv/symlink.c
- *
- * Handling of System V filesystem fast symlinks extensions.
- * Aug 2001, Christoph Hellwig (hch@infradead.org)
- */
-
-#include "sysv.h"
-#include <linux/namei.h>
-
-static void *sysv_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- nd_set_link(nd, (char *)SYSV_I(d_inode(dentry))->i_data);
- return NULL;
-}
-
-const struct inode_operations sysv_fast_symlink_inode_operations = {
- .readlink = generic_readlink,
- .follow_link = sysv_follow_link,
-};
extern const struct inode_operations sysv_file_inode_operations;
extern const struct inode_operations sysv_dir_inode_operations;
-extern const struct inode_operations sysv_fast_symlink_inode_operations;
extern const struct file_operations sysv_file_operations;
extern const struct file_operations sysv_dir_operations;
extern const struct address_space_operations sysv_aops;
memcpy(ui->data, symname, len);
((char *)ui->data)[len] = '\0';
+ inode->i_link = ui->data;
/*
* The terminating zero byte is not written to the flash media and it
* is put just to make later in-memory string processing simpler. Thus,
#include "ubifs.h"
#include <linux/mount.h>
-#include <linux/namei.h>
#include <linux/slab.h>
static int read_block(struct inode *inode, void *addr, unsigned int block,
ClearPageChecked(page);
}
-static void *ubifs_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- struct ubifs_inode *ui = ubifs_inode(d_inode(dentry));
-
- nd_set_link(nd, ui->data);
- return NULL;
-}
-
int ubifs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
struct inode *inode = file->f_mapping->host;
const struct inode_operations ubifs_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = ubifs_follow_link,
+ .follow_link = simple_follow_link,
.setattr = ubifs_setattr,
.getattr = ubifs_getattr,
.setxattr = ubifs_setxattr,
}
memcpy(ui->data, ino->data, ui->data_len);
((char *)ui->data)[ui->data_len] = '\0';
+ inode->i_link = ui->data;
break;
case S_IFBLK:
case S_IFCHR:
inode->i_fop = &ufs_dir_operations;
inode->i_mapping->a_ops = &ufs_aops;
} else if (S_ISLNK(inode->i_mode)) {
- if (!inode->i_blocks)
+ if (!inode->i_blocks) {
inode->i_op = &ufs_fast_symlink_inode_operations;
- else {
+ inode->i_link = (char *)UFS_I(inode)->i_u1.i_symlink;
+ } else {
inode->i_op = &ufs_symlink_inode_operations;
inode->i_mapping->a_ops = &ufs_aops;
}
} else {
/* fast symlink */
inode->i_op = &ufs_fast_symlink_inode_operations;
- memcpy(UFS_I(inode)->i_u1.i_symlink, symname, l);
+ inode->i_link = (char *)UFS_I(inode)->i_u1.i_symlink;
+ memcpy(inode->i_link, symname, l);
inode->i_size = l-1;
}
mark_inode_dirty(inode);
* ext2 symlink handling code
*/
-#include <linux/fs.h>
-#include <linux/namei.h>
-
#include "ufs_fs.h"
#include "ufs.h"
-
-static void *ufs_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- struct ufs_inode_info *p = UFS_I(d_inode(dentry));
- nd_set_link(nd, (char*)p->i_u1.i_symlink);
- return NULL;
-}
-
const struct inode_operations ufs_fast_symlink_inode_operations = {
.readlink = generic_readlink,
- .follow_link = ufs_follow_link,
+ .follow_link = simple_follow_link,
.setattr = ufs_setattr,
};
#include <linux/capability.h>
#include <linux/xattr.h>
-#include <linux/namei.h>
#include <linux/posix_acl.h>
#include <linux/security.h>
#include <linux/fiemap.h>
* we need to be very careful about how much stack we use.
* uio is kmalloced for this reason...
*/
-STATIC void *
+STATIC const char *
xfs_vn_follow_link(
struct dentry *dentry,
- struct nameidata *nd)
+ void **cookie)
{
char *link;
int error = -ENOMEM;
if (unlikely(error))
goto out_kfree;
- nd_set_link(nd, link);
- return NULL;
+ return *cookie = link;
out_kfree:
kfree(link);
out_err:
- nd_set_link(nd, ERR_PTR(error));
- return NULL;
+ return ERR_PTR(error);
}
STATIC int
/* declared over in file.c */
extern const struct file_operations debugfs_file_operations;
-extern const struct inode_operations debugfs_link_operations;
struct dentry *debugfs_create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
struct export_operations;
struct hd_geometry;
struct iovec;
-struct nameidata;
struct kiocb;
struct kobject;
struct pipe_inode_info;
struct pipe_inode_info *i_pipe;
struct block_device *i_bdev;
struct cdev *i_cdev;
+ char *i_link;
};
__u32 i_generation;
struct inode_operations {
struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
- void * (*follow_link) (struct dentry *, struct nameidata *);
+ const char * (*follow_link) (struct dentry *, void **);
int (*permission) (struct inode *, int);
struct posix_acl * (*get_acl)(struct inode *, int);
int (*readlink) (struct dentry *, char __user *,int);
- void (*put_link) (struct dentry *, struct nameidata *, void *);
+ void (*put_link) (struct inode *, void *);
int (*create) (struct inode *,struct dentry *, umode_t, bool);
int (*link) (struct dentry *,struct inode *,struct dentry *);
S_VERSION = 8,
};
+extern bool atime_needs_update(const struct path *, struct inode *);
extern void touch_atime(const struct path *);
static inline void file_accessed(struct file *file)
{
extern int readlink_copy(char __user *, int, const char *);
extern int page_readlink(struct dentry *, char __user *, int);
-extern void *page_follow_link_light(struct dentry *, struct nameidata *);
-extern void page_put_link(struct dentry *, struct nameidata *, void *);
+extern const char *page_follow_link_light(struct dentry *, void **);
+extern void page_put_link(struct inode *, void *);
extern int __page_symlink(struct inode *inode, const char *symname, int len,
int nofs);
extern int page_symlink(struct inode *inode, const char *symname, int len);
extern const struct inode_operations page_symlink_inode_operations;
-extern void kfree_put_link(struct dentry *, struct nameidata *, void *);
+extern void kfree_put_link(struct inode *, void *);
+extern void free_page_put_link(struct inode *, void *);
extern int generic_readlink(struct dentry *, char __user *, int);
extern void generic_fillattr(struct inode *, struct kstat *);
int vfs_getattr_nosec(struct path *path, struct kstat *stat);
void inode_sub_bytes(struct inode *inode, loff_t bytes);
loff_t inode_get_bytes(struct inode *inode);
void inode_set_bytes(struct inode *inode, loff_t bytes);
+const char *simple_follow_link(struct dentry *, void **);
+extern const struct inode_operations simple_symlink_inode_operations;
extern int iterate_dir(struct file *, struct dir_context *);
#ifndef _LINUX_NAMEI_H
#define _LINUX_NAMEI_H
-#include <linux/dcache.h>
-#include <linux/errno.h>
-#include <linux/linkage.h>
+#include <linux/kernel.h>
#include <linux/path.h>
-
-struct vfsmount;
-struct nameidata;
+#include <linux/fcntl.h>
+#include <linux/errno.h>
enum { MAX_NESTED_LINKS = 8 };
+#define MAXSYMLINKS 40
+
/*
* Type of the last component on LOOKUP_PARENT
*/
#define LOOKUP_ROOT 0x2000
#define LOOKUP_EMPTY 0x4000
-extern int user_path_at(int, const char __user *, unsigned, struct path *);
extern int user_path_at_empty(int, const char __user *, unsigned, struct path *, int *empty);
-#define user_path(name, path) user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW, path)
-#define user_lpath(name, path) user_path_at(AT_FDCWD, name, 0, path)
-#define user_path_dir(name, path) \
- user_path_at(AT_FDCWD, name, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path)
+static inline int user_path_at(int dfd, const char __user *name, unsigned flags,
+ struct path *path)
+{
+ return user_path_at_empty(dfd, name, flags, path, NULL);
+}
+
+static inline int user_path(const char __user *name, struct path *path)
+{
+ return user_path_at_empty(AT_FDCWD, name, LOOKUP_FOLLOW, path, NULL);
+}
+
+static inline int user_lpath(const char __user *name, struct path *path)
+{
+ return user_path_at_empty(AT_FDCWD, name, 0, path, NULL);
+}
+
+static inline int user_path_dir(const char __user *name, struct path *path)
+{
+ return user_path_at_empty(AT_FDCWD, name,
+ LOOKUP_FOLLOW | LOOKUP_DIRECTORY, path, NULL);
+}
extern int kern_path(const char *, unsigned, struct path *);
extern struct dentry *lock_rename(struct dentry *, struct dentry *);
extern void unlock_rename(struct dentry *, struct dentry *);
-extern void nd_jump_link(struct nameidata *nd, struct path *path);
-extern void nd_set_link(struct nameidata *nd, char *path);
-extern char *nd_get_link(struct nameidata *nd);
+extern void nd_jump_link(struct path *path);
static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
{
struct perf_event_context;
struct blk_plug;
struct filename;
+struct nameidata;
#define VMACACHE_BITS 2
#define VMACACHE_SIZE (1U << VMACACHE_BITS)
it with task_lock())
- initialized normally by setup_new_exec */
/* file system info */
- int link_count, total_link_count;
+ struct nameidata *nameidata;
#ifdef CONFIG_SYSVIPC
/* ipc stuff */
struct sysv_sem sysvsem;
struct vfsmount;
struct path;
struct qstr;
-struct nameidata;
struct iattr;
struct fown_struct;
struct file_operations;
* @inode_follow_link:
* Check permission to follow a symbolic link when looking up a pathname.
* @dentry contains the dentry structure for the link.
- * @nd contains the nameidata structure for the parent directory.
+ * @inode contains the inode, which itself is not stable in RCU-walk
+ * @rcu indicates whether we are in RCU-walk mode.
* Return 0 if permission is granted.
* @inode_permission:
* Check permission before accessing an inode. This hook is called by the
int (*inode_rename) (struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry);
int (*inode_readlink) (struct dentry *dentry);
- int (*inode_follow_link) (struct dentry *dentry, struct nameidata *nd);
+ int (*inode_follow_link) (struct dentry *dentry, struct inode *inode,
+ bool rcu);
int (*inode_permission) (struct inode *inode, int mask);
int (*inode_setattr) (struct dentry *dentry, struct iattr *attr);
int (*inode_getattr) (const struct path *path);
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags);
int security_inode_readlink(struct dentry *dentry);
-int security_inode_follow_link(struct dentry *dentry, struct nameidata *nd);
+int security_inode_follow_link(struct dentry *dentry, struct inode *inode,
+ bool rcu);
int security_inode_permission(struct inode *inode, int mask);
int security_inode_setattr(struct dentry *dentry, struct iattr *attr);
int security_inode_getattr(const struct path *path);
}
static inline int security_inode_follow_link(struct dentry *dentry,
- struct nameidata *nd)
+ struct inode *inode,
+ bool rcu)
{
return 0;
}
return -ENOMEM;
}
inode->i_op = &shmem_short_symlink_operations;
+ inode->i_link = info->symlink;
} else {
error = shmem_getpage(inode, 0, &page, SGP_WRITE, NULL);
if (error) {
return 0;
}
-static void *shmem_follow_short_symlink(struct dentry *dentry, struct nameidata *nd)
-{
- nd_set_link(nd, SHMEM_I(d_inode(dentry))->symlink);
- return NULL;
-}
-
-static void *shmem_follow_link(struct dentry *dentry, struct nameidata *nd)
+static const char *shmem_follow_link(struct dentry *dentry, void **cookie)
{
struct page *page = NULL;
int error = shmem_getpage(d_inode(dentry), 0, &page, SGP_READ, NULL);
- nd_set_link(nd, error ? ERR_PTR(error) : kmap(page));
- if (page)
- unlock_page(page);
- return page;
+ if (error)
+ return ERR_PTR(error);
+ unlock_page(page);
+ *cookie = page;
+ return kmap(page);
}
-static void shmem_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
+static void shmem_put_link(struct inode *unused, void *cookie)
{
- if (!IS_ERR(nd_get_link(nd))) {
- struct page *page = cookie;
- kunmap(page);
- mark_page_accessed(page);
- page_cache_release(page);
- }
+ struct page *page = cookie;
+ kunmap(page);
+ mark_page_accessed(page);
+ page_cache_release(page);
}
#ifdef CONFIG_TMPFS_XATTR
static const struct inode_operations shmem_short_symlink_operations = {
.readlink = generic_readlink,
- .follow_link = shmem_follow_short_symlink,
+ .follow_link = simple_follow_link,
#ifdef CONFIG_TMPFS_XATTR
.setxattr = shmem_setxattr,
.getxattr = shmem_getxattr,
return 0;
}
-static int cap_inode_follow_link(struct dentry *dentry,
- struct nameidata *nameidata)
+static int cap_inode_follow_link(struct dentry *dentry, struct inode *inode,
+ bool rcu)
{
return 0;
}
return security_ops->inode_readlink(dentry);
}
-int security_inode_follow_link(struct dentry *dentry, struct nameidata *nd)
+int security_inode_follow_link(struct dentry *dentry, struct inode *inode,
+ bool rcu)
{
- if (unlikely(IS_PRIVATE(d_backing_inode(dentry))))
+ if (unlikely(IS_PRIVATE(inode)))
return 0;
- return security_ops->inode_follow_link(dentry, nd);
+ return security_ops->inode_follow_link(dentry, inode, rcu);
}
int security_inode_permission(struct inode *inode, int mask)
rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd);
- rc2 = avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata);
+ rc2 = avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata, 0);
+ if (rc2)
+ return rc2;
+ return rc;
+}
+
+int avc_has_perm_flags(u32 ssid, u32 tsid, u16 tclass,
+ u32 requested, struct common_audit_data *auditdata,
+ int flags)
+{
+ struct av_decision avd;
+ int rc, rc2;
+
+ rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd);
+
+ rc2 = avc_audit(ssid, tsid, tclass, requested, &avd, rc,
+ auditdata, flags);
if (rc2)
return rc2;
return rc;
rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
if (audit == SECURITY_CAP_AUDIT) {
- int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
+ int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
if (rc2)
return rc2;
}
return dentry_has_perm(cred, dentry, FILE__READ);
}
-static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
+static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
+ bool rcu)
{
const struct cred *cred = current_cred();
+ struct common_audit_data ad;
+ struct inode_security_struct *isec;
+ u32 sid;
- return dentry_has_perm(cred, dentry, FILE__READ);
+ validate_creds(cred);
+
+ ad.type = LSM_AUDIT_DATA_DENTRY;
+ ad.u.dentry = dentry;
+ sid = cred_sid(cred);
+ isec = inode->i_security;
+
+ return avc_has_perm_flags(sid, isec->sid, isec->sclass, FILE__READ, &ad,
+ rcu ? MAY_NOT_BLOCK : 0);
}
static noinline int audit_inode_permission(struct inode *inode,
u16 tclass, u32 requested,
struct av_decision *avd,
int result,
- struct common_audit_data *a)
+ struct common_audit_data *a,
+ int flags)
{
u32 audited, denied;
audited = avc_audit_required(requested, avd, result, 0, &denied);
return 0;
return slow_avc_audit(ssid, tsid, tclass,
requested, audited, denied, result,
- a, 0);
+ a, flags);
}
#define AVC_STRICT 1 /* Ignore permissive mode. */
int avc_has_perm(u32 ssid, u32 tsid,
u16 tclass, u32 requested,
struct common_audit_data *auditdata);
+int avc_has_perm_flags(u32 ssid, u32 tsid,
+ u16 tclass, u32 requested,
+ struct common_audit_data *auditdata,
+ int flags);
u32 avc_policy_seqno(void);
projects / mirror_ubuntu-artful-kernel.git / commitdiff