[mirror_ubuntu-zesty-kernel.git] / fs / coda / dir.c


/*
 * Directory operations for Coda filesystem
 * Original version: (C) 1996 P. Braam and M. Callahan
 * Rewritten for Linux 2.1. (C) 1997 Carnegie Mellon University
 * 
 * Carnegie Mellon encourages users to contribute improvements to
 * the Coda project. Contact Peter Braam (coda@cs.cmu.edu).
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/namei.h>
#include <linux/uaccess.h>

#include <linux/coda.h>
#include <linux/coda_psdev.h>
#include "coda_linux.h"
#include "coda_cache.h"

#include "coda_int.h"

/* dir inode-ops */
static int coda_create(struct inode *dir, struct dentry *new, umode_t mode, bool excl);
static struct dentry *coda_lookup(struct inode *dir, struct dentry *target, unsigned int flags);
static int coda_link(struct dentry *old_dentry, struct inode *dir_inode, 
		     struct dentry *entry);
static int coda_unlink(struct inode *dir_inode, struct dentry *entry);
static int coda_symlink(struct inode *dir_inode, struct dentry *entry,
			const char *symname);
static int coda_mkdir(struct inode *dir_inode, struct dentry *entry, umode_t mode);
static int coda_rmdir(struct inode *dir_inode, struct dentry *entry);
static int coda_rename(struct inode *old_inode, struct dentry *old_dentry, 
                       struct inode *new_inode, struct dentry *new_dentry);

/* dir file-ops */
static int coda_readdir(struct file *file, struct dir_context *ctx);

/* dentry ops */
static int coda_dentry_revalidate(struct dentry *de, unsigned int flags);
static int coda_dentry_delete(const struct dentry *);

/* support routines */
static int coda_venus_readdir(struct file *, struct dir_context *);

/* same as fs/bad_inode.c */
static int coda_return_EIO(void)
{
	return -EIO;
}
#define CODA_EIO_ERROR ((void *) (coda_return_EIO))

const struct dentry_operations coda_dentry_operations =
{
	.d_revalidate	= coda_dentry_revalidate,
	.d_delete	= coda_dentry_delete,
};

const struct inode_operations coda_dir_inode_operations =
{
	.create		= coda_create,
	.lookup		= coda_lookup,
	.link		= coda_link,
	.unlink		= coda_unlink,
	.symlink	= coda_symlink,
	.mkdir		= coda_mkdir,
	.rmdir		= coda_rmdir,
	.mknod		= CODA_EIO_ERROR,
	.rename		= coda_rename,
	.permission	= coda_permission,
	.getattr	= coda_getattr,
	.setattr	= coda_setattr,
};

const struct file_operations coda_dir_operations = {
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
	.iterate	= coda_readdir,
	.open		= coda_open,
	.release	= coda_release,
	.fsync		= coda_fsync,
};


/* inode operations for directories */
/* access routines: lookup, readlink, permission */
static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, unsigned int flags)
{
	struct super_block *sb = dir->i_sb;
	const char *name = entry->d_name.name;
	size_t length = entry->d_name.len;
	struct inode *inode;
	int type = 0;

	if (length > CODA_MAXNAMLEN) {
		pr_err("name too long: lookup, %s (%*s)\n",
		       coda_i2s(dir), (int)length, name);
		return ERR_PTR(-ENAMETOOLONG);
	}

	/* control object, create inode on the fly */
	if (is_root_inode(dir) && coda_iscontrol(name, length)) {
		inode = coda_cnode_makectl(sb);
		type = CODA_NOCACHE;
	} else {
		struct CodaFid fid = { { 0, } };
		int error = venus_lookup(sb, coda_i2f(dir), name, length,
				     &type, &fid);
		inode = !error ? coda_cnode_make(&fid, sb) : ERR_PTR(error);
	}

	if (!IS_ERR(inode) && (type & CODA_NOCACHE))
		coda_flag_inode(inode, C_VATTR | C_PURGE);

	if (inode == ERR_PTR(-ENOENT))
		inode = NULL;

	return d_splice_alias(inode, entry);
}


int coda_permission(struct inode *inode, int mask)
{
	int error;

	if (mask & MAY_NOT_BLOCK)
		return -ECHILD;

	mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
 
	if (!mask)
		return 0;

	if ((mask & MAY_EXEC) && !execute_ok(inode))
		return -EACCES;

	if (coda_cache_check(inode, mask))
		return 0;

	error = venus_access(inode->i_sb, coda_i2f(inode), mask);
    
	if (!error)
		coda_cache_enter(inode, mask);

	return error;
}


static inline void coda_dir_update_mtime(struct inode *dir)
{
#ifdef REQUERY_VENUS_FOR_MTIME
	/* invalidate the directory cnode's attributes so we refetch the
	 * attributes from venus next time the inode is referenced */
	coda_flag_inode(dir, C_VATTR);
#else
	/* optimistically we can also act as if our nose bleeds. The
	 * granularity of the mtime is coarse anyways so we might actually be
	 * right most of the time. Note: we only do this for directories. */
	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
#endif
}

/* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
 * trick to fool GNU find's optimizations. If we can't be sure of the link
 * (because of volume mount points) we set i_nlink to 1 which forces find
 * to consider every child as a possible directory. We should also never
 * see an increment or decrement for deleted directories where i_nlink == 0 */
static inline void coda_dir_inc_nlink(struct inode *dir)
{
	if (dir->i_nlink >= 2)
		inc_nlink(dir);
}

static inline void coda_dir_drop_nlink(struct inode *dir)
{
	if (dir->i_nlink > 2)
		drop_nlink(dir);
}

/* creation routines: create, mknod, mkdir, link, symlink */
static int coda_create(struct inode *dir, struct dentry *de, umode_t mode, bool excl)
{
	int error;
	const char *name=de->d_name.name;
	int length=de->d_name.len;
	struct inode *inode;
	struct CodaFid newfid;
	struct coda_vattr attrs;

	if (is_root_inode(dir) && coda_iscontrol(name, length))
		return -EPERM;

	error = venus_create(dir->i_sb, coda_i2f(dir), name, length, 
				0, mode, &newfid, &attrs);
	if (error)
		goto err_out;

	inode = coda_iget(dir->i_sb, &newfid, &attrs);
	if (IS_ERR(inode)) {
		error = PTR_ERR(inode);
		goto err_out;
	}

	/* invalidate the directory cnode's attributes */
	coda_dir_update_mtime(dir);
	d_instantiate(de, inode);
	return 0;
err_out:
	d_drop(de);
	return error;
}

static int coda_mkdir(struct inode *dir, struct dentry *de, umode_t mode)
{
	struct inode *inode;
	struct coda_vattr attrs;
	const char *name = de->d_name.name;
	int len = de->d_name.len;
	int error;
	struct CodaFid newfid;

	if (is_root_inode(dir) && coda_iscontrol(name, len))
		return -EPERM;

	attrs.va_mode = mode;
	error = venus_mkdir(dir->i_sb, coda_i2f(dir), 
			       name, len, &newfid, &attrs);
	if (error)
		goto err_out;
         
	inode = coda_iget(dir->i_sb, &newfid, &attrs);
	if (IS_ERR(inode)) {
		error = PTR_ERR(inode);
		goto err_out;
	}

	/* invalidate the directory cnode's attributes */
	coda_dir_inc_nlink(dir);
	coda_dir_update_mtime(dir);
	d_instantiate(de, inode);
	return 0;
err_out:
	d_drop(de);
	return error;
}

/* try to make de an entry in dir_inodde linked to source_de */ 
static int coda_link(struct dentry *source_de, struct inode *dir_inode, 
	  struct dentry *de)
{
	struct inode *inode = source_de->d_inode;
        const char * name = de->d_name.name;
	int len = de->d_name.len;
	int error;

	if (is_root_inode(dir_inode) && coda_iscontrol(name, len))
		return -EPERM;

	error = venus_link(dir_inode->i_sb, coda_i2f(inode),
			   coda_i2f(dir_inode), (const char *)name, len);
	if (error) {
		d_drop(de);
		return error;
	}

	coda_dir_update_mtime(dir_inode);
	ihold(inode);
	d_instantiate(de, inode);
	inc_nlink(inode);
	return 0;
}


static int coda_symlink(struct inode *dir_inode, struct dentry *de,
			const char *symname)
{
	const char *name = de->d_name.name;
	int len = de->d_name.len;
	int symlen;
	int error;

	if (is_root_inode(dir_inode) && coda_iscontrol(name, len))
		return -EPERM;

	symlen = strlen(symname);
	if (symlen > CODA_MAXPATHLEN)
		return -ENAMETOOLONG;

	/*
	 * This entry is now negative. Since we do not create
	 * an inode for the entry we have to drop it.
	 */
	d_drop(de);
	error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
			      symname, symlen);

	/* mtime is no good anymore */
	if (!error)
		coda_dir_update_mtime(dir_inode);

	return error;
}

/* destruction routines: unlink, rmdir */
static int coda_unlink(struct inode *dir, struct dentry *de)
{
        int error;
	const char *name = de->d_name.name;
	int len = de->d_name.len;

	error = venus_remove(dir->i_sb, coda_i2f(dir), name, len);
	if (error)
		return error;

	coda_dir_update_mtime(dir);
	drop_nlink(de->d_inode);
	return 0;
}

static int coda_rmdir(struct inode *dir, struct dentry *de)
{
	const char *name = de->d_name.name;
	int len = de->d_name.len;
	int error;

	error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
	if (!error) {
		/* VFS may delete the child */
		if (de->d_inode)
			clear_nlink(de->d_inode);

		/* fix the link count of the parent */
		coda_dir_drop_nlink(dir);
		coda_dir_update_mtime(dir);
	}
	return error;
}

/* rename */
static int coda_rename(struct inode *old_dir, struct dentry *old_dentry,
		       struct inode *new_dir, struct dentry *new_dentry)
{
	const char *old_name = old_dentry->d_name.name;
	const char *new_name = new_dentry->d_name.name;
	int old_length = old_dentry->d_name.len;
	int new_length = new_dentry->d_name.len;
	int error;

	error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
			     coda_i2f(new_dir), old_length, new_length,
			     (const char *) old_name, (const char *)new_name);
	if (!error) {
		if (new_dentry->d_inode) {
			if (S_ISDIR(new_dentry->d_inode->i_mode)) {
				coda_dir_drop_nlink(old_dir);
				coda_dir_inc_nlink(new_dir);
			}
			coda_dir_update_mtime(old_dir);
			coda_dir_update_mtime(new_dir);
			coda_flag_inode(new_dentry->d_inode, C_VATTR);
		} else {
			coda_flag_inode(old_dir, C_VATTR);
			coda_flag_inode(new_dir, C_VATTR);
		}
	}
	return error;
}


/* file operations for directories */
static int coda_readdir(struct file *coda_file, struct dir_context *ctx)
{
	struct coda_file_info *cfi;
	struct file *host_file;
	int ret;

	cfi = CODA_FTOC(coda_file);
	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
	host_file = cfi->cfi_container;

	if (host_file->f_op->iterate) {
		struct inode *host_inode = file_inode(host_file);
		mutex_lock(&host_inode->i_mutex);
		ret = -ENOENT;
		if (!IS_DEADDIR(host_inode)) {
			ret = host_file->f_op->iterate(host_file, ctx);
			file_accessed(host_file);
		}
		mutex_unlock(&host_inode->i_mutex);
		return ret;
	}
	/* Venus: we must read Venus dirents from a file */
	return coda_venus_readdir(coda_file, ctx);
}

static inline unsigned int CDT2DT(unsigned char cdt)
{
	unsigned int dt;

	switch(cdt) {
	case CDT_UNKNOWN: dt = DT_UNKNOWN; break;
	case CDT_FIFO:	  dt = DT_FIFO;    break;
	case CDT_CHR:	  dt = DT_CHR;     break;
	case CDT_DIR:	  dt = DT_DIR;     break;
	case CDT_BLK:	  dt = DT_BLK;     break;
	case CDT_REG:	  dt = DT_REG;     break;
	case CDT_LNK:	  dt = DT_LNK;     break;
	case CDT_SOCK:	  dt = DT_SOCK;    break;
	case CDT_WHT:	  dt = DT_WHT;     break;
	default:	  dt = DT_UNKNOWN; break;
	}
	return dt;
}

/* support routines */
static int coda_venus_readdir(struct file *coda_file, struct dir_context *ctx)
{
	struct coda_file_info *cfi;
	struct coda_inode_info *cii;
	struct file *host_file;
	struct venus_dirent *vdir;
	unsigned long vdir_size = offsetof(struct venus_dirent, d_name);
	unsigned int type;
	struct qstr name;
	ino_t ino;
	int ret;

	cfi = CODA_FTOC(coda_file);
	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
	host_file = cfi->cfi_container;

	cii = ITOC(file_inode(coda_file));

	vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
	if (!vdir) return -ENOMEM;

	if (!dir_emit_dots(coda_file, ctx))
		goto out;

	while (1) {
		/* read entries from the directory file */
		ret = kernel_read(host_file, ctx->pos - 2, (char *)vdir,
				  sizeof(*vdir));
		if (ret < 0) {
			pr_err("%s: read dir %s failed %d\n",
			       __func__, coda_f2s(&cii->c_fid), ret);
			break;
		}
		if (ret == 0) break; /* end of directory file reached */

		/* catch truncated reads */
		if (ret < vdir_size || ret < vdir_size + vdir->d_namlen) {
			pr_err("%s: short read on %s\n",
			       __func__, coda_f2s(&cii->c_fid));
			ret = -EBADF;
			break;
		}
		/* validate whether the directory file actually makes sense */
		if (vdir->d_reclen < vdir_size + vdir->d_namlen) {
			pr_err("%s: invalid dir %s\n",
			       __func__, coda_f2s(&cii->c_fid));
			ret = -EBADF;
			break;
		}

		name.len = vdir->d_namlen;
		name.name = vdir->d_name;

		/* Make sure we skip '.' and '..', we already got those */
		if (name.name[0] == '.' && (name.len == 1 ||
		    (name.name[1] == '.' && name.len == 2)))
			vdir->d_fileno = name.len = 0;

		/* skip null entries */
		if (vdir->d_fileno && name.len) {
			ino = vdir->d_fileno;
			type = CDT2DT(vdir->d_type);
			if (!dir_emit(ctx, name.name, name.len, ino, type))
				break;
		}
		/* we'll always have progress because d_reclen is unsigned and
		 * we've already established it is non-zero. */
		ctx->pos += vdir->d_reclen;
	}
out:
	kfree(vdir);
	return 0;
}

/* called when a cache lookup succeeds */
static int coda_dentry_revalidate(struct dentry *de, unsigned int flags)
{
	struct inode *inode;
	struct coda_inode_info *cii;

	if (flags & LOOKUP_RCU)
		return -ECHILD;

	inode = de->d_inode;
	if (!inode || is_root_inode(inode))
		goto out;
	if (is_bad_inode(inode))
		goto bad;

	cii = ITOC(de->d_inode);
	if (!(cii->c_flags & (C_PURGE | C_FLUSH)))
		goto out;

	shrink_dcache_parent(de);

	/* propagate for a flush */
	if (cii->c_flags & C_FLUSH) 
		coda_flag_inode_children(inode, C_FLUSH);

	if (d_count(de) > 1)
		/* pretend it's valid, but don't change the flags */
		goto out;

	/* clear the flags. */
	spin_lock(&cii->c_lock);
	cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
	spin_unlock(&cii->c_lock);
bad:
	return 0;
out:
	return 1;
}

/*
 * This is the callback from dput() when d_count is going to 0.
 * We use this to unhash dentries with bad inodes.
 */
static int coda_dentry_delete(const struct dentry * dentry)
{
	int flags;

	if (!dentry->d_inode) 
		return 0;

	flags = (ITOC(dentry->d_inode)->c_flags) & C_PURGE;
	if (is_bad_inode(dentry->d_inode) || flags) {
		return 1;
	}
	return 0;
}


/*
 * This is called when we want to check if the inode has
 * changed on the server.  Coda makes this easy since the
 * cache manager Venus issues a downcall to the kernel when this 
 * happens 
 */
int coda_revalidate_inode(struct inode *inode)
{
	struct coda_vattr attr;
	int error;
	int old_mode;
	ino_t old_ino;
	struct coda_inode_info *cii = ITOC(inode);

	if (!cii->c_flags)
		return 0;

	if (cii->c_flags & (C_VATTR | C_PURGE | C_FLUSH)) {
		error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr);
		if (error)
			return -EIO;

		/* this inode may be lost if:
		   - it's ino changed 
		   - type changes must be permitted for repair and
		   missing mount points.
		*/
		old_mode = inode->i_mode;
		old_ino = inode->i_ino;
		coda_vattr_to_iattr(inode, &attr);

		if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) {
			pr_warn("inode %ld, fid %s changed type!\n",
				inode->i_ino, coda_f2s(&(cii->c_fid)));
		}

		/* the following can happen when a local fid is replaced 
		   with a global one, here we lose and declare the inode bad */
		if (inode->i_ino != old_ino)
			return -EIO;
		
		coda_flag_inode_children(inode, C_FLUSH);

		spin_lock(&cii->c_lock);
		cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
		spin_unlock(&cii->c_lock);
	}
	return 0;
}
Commit	Line	Data
1da177e4 LT	1
	2	/*
	3	* Directory operations for Coda filesystem
	4	* Original version: (C) 1996 P. Braam and M. Callahan
	5	* Rewritten for Linux 2.1. (C) 1997 Carnegie Mellon University
	6	*
	7	* Carnegie Mellon encourages users to contribute improvements to
	8	* the Coda project. Contact Peter Braam (coda@cs.cmu.edu).
	9	*/
	10
	11	#include <linux/types.h>
	12	#include <linux/kernel.h>
	13	#include <linux/time.h>
	14	#include <linux/fs.h>
5a0e3ad6	15	#include <linux/slab.h>
1da177e4 LT	16	#include <linux/file.h>
	17	#include <linux/stat.h>
	18	#include <linux/errno.h>
	19	#include <linux/string.h>
b5ce1d83	20	#include <linux/spinlock.h>
34286d66	21	#include <linux/namei.h>
834b46c3	22	#include <linux/uaccess.h>
1da177e4 LT	23
1da177e4 LT	24	#include <linux/coda.h>
1da177e4	25	#include <linux/coda_psdev.h>
31a203df AV	26	#include "coda_linux.h"
31a203df AV	27	#include "coda_cache.h"
1da177e4	28
c98d8cfb AB	29	#include "coda_int.h"
c98d8cfb AB	30
1da177e4	31	/* dir inode-ops */
ebfc3b49	32	static int coda_create(struct inode dir, struct dentry new, umode_t mode, bool excl);
00cd8dd3	33	static struct dentry coda_lookup(struct inode dir, struct dentry *target, unsigned int flags);
1da177e4 LT	34	static int coda_link(struct dentry old_dentry, struct inode dir_inode,
	35	struct dentry *entry);
	36	static int coda_unlink(struct inode dir_inode, struct dentry entry);
	37	static int coda_symlink(struct inode dir_inode, struct dentry entry,
	38	const char *symname);
18bb1db3	39	static int coda_mkdir(struct inode dir_inode, struct dentry entry, umode_t mode);
1da177e4 LT	40	static int coda_rmdir(struct inode dir_inode, struct dentry entry);
	41	static int coda_rename(struct inode old_inode, struct dentry old_dentry,
	42	struct inode new_inode, struct dentry new_dentry);
	43
	44	/* dir file-ops */
e924f251	45	static int coda_readdir(struct file file, struct dir_context ctx);
1da177e4 LT	46
1da177e4 LT	47	/* dentry ops */
0b728e19	48	static int coda_dentry_revalidate(struct dentry *de, unsigned int flags);
fe15ce44	49	static int coda_dentry_delete(const struct dentry *);
1da177e4 LT	50
1da177e4 LT	51	/* support routines */
e924f251	52	static int coda_venus_readdir(struct file , struct dir_context );
1da177e4 LT	53
	54	/* same as fs/bad_inode.c */
	55	static int coda_return_EIO(void)
	56	{
	57	return -EIO;
	58	}
	59	#define CODA_EIO_ERROR ((void *) (coda_return_EIO))
	60
9501e4c4	61	const struct dentry_operations coda_dentry_operations =
1da177e4 LT	62	{
	63	.d_revalidate = coda_dentry_revalidate,
	64	.d_delete = coda_dentry_delete,
	65	};
	66
754661f1	67	const struct inode_operations coda_dir_inode_operations =
1da177e4 LT	68	{
	69	.create = coda_create,
	70	.lookup = coda_lookup,
	71	.link = coda_link,
	72	.unlink = coda_unlink,
	73	.symlink = coda_symlink,
	74	.mkdir = coda_mkdir,
	75	.rmdir = coda_rmdir,
	76	.mknod = CODA_EIO_ERROR,
	77	.rename = coda_rename,
	78	.permission = coda_permission,
	79	.getattr = coda_getattr,
	80	.setattr = coda_setattr,
	81	};
	82
4b6f5d20	83	const struct file_operations coda_dir_operations = {
1da177e4 LT	84	.llseek = generic_file_llseek,
1da177e4 LT	85	.read = generic_read_dir,
e924f251	86	.iterate = coda_readdir,
1da177e4	87	.open = coda_open,
1da177e4 LT	88	.release = coda_release,
	89	.fsync = coda_fsync,
	90	};
	91
	92
	93	/* inode operations for directories */
	94	/* access routines: lookup, readlink, permission */
00cd8dd3	95	static struct dentry coda_lookup(struct inode dir, struct dentry *entry, unsigned int flags)
1da177e4	96	{
f4947fbc	97	struct super_block *sb = dir->i_sb;
1da177e4 LT	98	const char *name = entry->d_name.name;
1da177e4 LT	99	size_t length = entry->d_name.len;
f4947fbc AV	100	struct inode *inode;
f4947fbc AV	101	int type = 0;
ed36f723 JH	102
ed36f723 JH	103	if (length > CODA_MAXNAMLEN) {
d9b4b319	104	pr_err("name too long: lookup, %s (%*s)\n",
1da177e4 LT	105	coda_i2s(dir), (int)length, name);
	106	return ERR_PTR(-ENAMETOOLONG);
	107	}
	108
ed36f723	109	/* control object, create inode on the fly */
a7400222	110	if (is_root_inode(dir) && coda_iscontrol(name, length)) {
f4947fbc	111	inode = coda_cnode_makectl(sb);
ed36f723	112	type = CODA_NOCACHE;
f4947fbc AV	113	} else {
	114	struct CodaFid fid = { { 0, } };
	115	int error = venus_lookup(sb, coda_i2f(dir), name, length,
	116	&type, &fid);
	117	inode = !error ? coda_cnode_make(&fid, sb) : ERR_PTR(error);
ed36f723 JH	118	}
ed36f723 JH	119
f4947fbc	120	if (!IS_ERR(inode) && (type & CODA_NOCACHE))
ed36f723 JH	121	coda_flag_inode(inode, C_VATTR \| C_PURGE);
ed36f723 JH	122
f4947fbc AV	123	if (inode == ERR_PTR(-ENOENT))
	124	inode = NULL;
	125
ed36f723	126	return d_splice_alias(inode, entry);
1da177e4 LT	127	}
	128
	129
10556cb2	130	int coda_permission(struct inode *inode, int mask)
1da177e4	131	{
f7cc02b8	132	int error;
e6305c43	133
10556cb2	134	if (mask & MAY_NOT_BLOCK)
b74c79e9 NP	135	return -ECHILD;
b74c79e9 NP	136
e6305c43	137	mask &= MAY_READ \| MAY_WRITE \| MAY_EXEC;
1da177e4 LT	138
1da177e4 LT	139	if (!mask)
f7cc02b8	140	return 0;
1da177e4	141
f696a365 MS	142	if ((mask & MAY_EXEC) && !execute_ok(inode))
	143	return -EACCES;
	144
1da177e4	145	if (coda_cache_check(inode, mask))
f7cc02b8	146	return 0;
1da177e4	147
f7cc02b8	148	error = venus_access(inode->i_sb, coda_i2f(inode), mask);
1da177e4 LT	149
	150	if (!error)
	151	coda_cache_enter(inode, mask);
	152
d728900c	153	return error;
1da177e4 LT	154	}
	155
	156
d728900c	157	static inline void coda_dir_update_mtime(struct inode *dir)
1da177e4 LT	158	{
	159	#ifdef REQUERY_VENUS_FOR_MTIME
	160	/* invalidate the directory cnode's attributes so we refetch the
	161	* attributes from venus next time the inode is referenced */
	162	coda_flag_inode(dir, C_VATTR);
	163	#else
	164	/* optimistically we can also act as if our nose bleeds. The
d728900c JH	165	* granularity of the mtime is coarse anyways so we might actually be
d728900c JH	166	* right most of the time. Note: we only do this for directories. */
1da177e4 LT	167	dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
1da177e4 LT	168	#endif
d728900c JH	169	}
	170
	171	/* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
	172	* trick to fool GNU find's optimizations. If we can't be sure of the link
	173	* (because of volume mount points) we set i_nlink to 1 which forces find
	174	* to consider every child as a possible directory. We should also never
	175	* see an increment or decrement for deleted directories where i_nlink == 0 */
	176	static inline void coda_dir_inc_nlink(struct inode *dir)
	177	{
	178	if (dir->i_nlink >= 2)
	179	inc_nlink(dir);
	180	}
	181
	182	static inline void coda_dir_drop_nlink(struct inode *dir)
	183	{
	184	if (dir->i_nlink > 2)
	185	drop_nlink(dir);
1da177e4 LT	186	}
	187
	188	/* creation routines: create, mknod, mkdir, link, symlink */
ebfc3b49	189	static int coda_create(struct inode dir, struct dentry de, umode_t mode, bool excl)
1da177e4	190	{
f7cc02b8	191	int error;
1da177e4 LT	192	const char *name=de->d_name.name;
	193	int length=de->d_name.len;
	194	struct inode *inode;
	195	struct CodaFid newfid;
	196	struct coda_vattr attrs;
	197
a7400222	198	if (is_root_inode(dir) && coda_iscontrol(name, length))
1da177e4	199	return -EPERM;
1da177e4 LT	200
	201	error = venus_create(dir->i_sb, coda_i2f(dir), name, length,
	202	0, mode, &newfid, &attrs);
f7cc02b8 YA	203	if (error)
f7cc02b8 YA	204	goto err_out;
1da177e4 LT	205
1da177e4 LT	206	inode = coda_iget(dir->i_sb, &newfid, &attrs);
f7cc02b8 YA	207	if (IS_ERR(inode)) {
	208	error = PTR_ERR(inode);
	209	goto err_out;
1da177e4 LT	210	}
	211
	212	/* invalidate the directory cnode's attributes */
d728900c	213	coda_dir_update_mtime(dir);
1da177e4	214	d_instantiate(de, inode);
d728900c	215	return 0;
f7cc02b8 YA	216	err_out:
	217	d_drop(de);
	218	return error;
1da177e4 LT	219	}
1da177e4 LT	220
18bb1db3	221	static int coda_mkdir(struct inode dir, struct dentry de, umode_t mode)
1da177e4 LT	222	{
	223	struct inode *inode;
	224	struct coda_vattr attrs;
	225	const char *name = de->d_name.name;
	226	int len = de->d_name.len;
	227	int error;
	228	struct CodaFid newfid;
	229
a7400222	230	if (is_root_inode(dir) && coda_iscontrol(name, len))
1da177e4	231	return -EPERM;
1da177e4 LT	232
	233	attrs.va_mode = mode;
	234	error = venus_mkdir(dir->i_sb, coda_i2f(dir),
	235	name, len, &newfid, &attrs);
f7cc02b8 YA	236	if (error)
f7cc02b8 YA	237	goto err_out;
1da177e4 LT	238
1da177e4 LT	239	inode = coda_iget(dir->i_sb, &newfid, &attrs);
f7cc02b8 YA	240	if (IS_ERR(inode)) {
	241	error = PTR_ERR(inode);
	242	goto err_out;
1da177e4	243	}
d728900c	244
1da177e4	245	/* invalidate the directory cnode's attributes */
d728900c JH	246	coda_dir_inc_nlink(dir);
d728900c JH	247	coda_dir_update_mtime(dir);
1da177e4	248	d_instantiate(de, inode);
d728900c	249	return 0;
f7cc02b8 YA	250	err_out:
	251	d_drop(de);
	252	return error;
1da177e4 LT	253	}
	254
	255	/* try to make de an entry in dir_inodde linked to source_de */
	256	static int coda_link(struct dentry source_de, struct inode dir_inode,
	257	struct dentry *de)
	258	{
	259	struct inode *inode = source_de->d_inode;
	260	const char * name = de->d_name.name;
	261	int len = de->d_name.len;
	262	int error;
	263
a7400222	264	if (is_root_inode(dir_inode) && coda_iscontrol(name, len))
1da177e4	265	return -EPERM;
1da177e4 LT	266
	267	error = venus_link(dir_inode->i_sb, coda_i2f(inode),
	268	coda_i2f(dir_inode), (const char *)name, len);
d728900c	269	if (error) {
1da177e4	270	d_drop(de);
f7cc02b8	271	return error;
1da177e4 LT	272	}
1da177e4 LT	273
d728900c	274	coda_dir_update_mtime(dir_inode);
7de9c6ee	275	ihold(inode);
1da177e4	276	d_instantiate(de, inode);
d8c76e6f	277	inc_nlink(inode);
f7cc02b8	278	return 0;
1da177e4 LT	279	}
	280
	281
	282	static int coda_symlink(struct inode dir_inode, struct dentry de,
	283	const char *symname)
	284	{
f7cc02b8	285	const char *name = de->d_name.name;
1da177e4 LT	286	int len = de->d_name.len;
1da177e4 LT	287	int symlen;
f7cc02b8	288	int error;
1da177e4	289
a7400222	290	if (is_root_inode(dir_inode) && coda_iscontrol(name, len))
1da177e4	291	return -EPERM;
1da177e4 LT	292
1da177e4 LT	293	symlen = strlen(symname);
f7cc02b8	294	if (symlen > CODA_MAXPATHLEN)
1da177e4	295	return -ENAMETOOLONG;
1da177e4 LT	296
	297	/*
	298	* This entry is now negative. Since we do not create
d728900c	299	* an inode for the entry we have to drop it.
1da177e4 LT	300	*/
1da177e4 LT	301	d_drop(de);
d728900c	302	error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
1da177e4 LT	303	symname, symlen);
	304
	305	/* mtime is no good anymore */
f7cc02b8	306	if (!error)
d728900c	307	coda_dir_update_mtime(dir_inode);
1da177e4	308
d728900c	309	return error;
1da177e4 LT	310	}
	311
	312	/* destruction routines: unlink, rmdir */
9fe76c76	313	static int coda_unlink(struct inode dir, struct dentry de)
1da177e4 LT	314	{
	315	int error;
	316	const char *name = de->d_name.name;
	317	int len = de->d_name.len;
	318
d728900c	319	error = venus_remove(dir->i_sb, coda_i2f(dir), name, len);
f7cc02b8	320	if (error)
d728900c	321	return error;
1da177e4	322
d728900c	323	coda_dir_update_mtime(dir);
9a53c3a7	324	drop_nlink(de->d_inode);
d728900c	325	return 0;
1da177e4 LT	326	}
1da177e4 LT	327
9fe76c76	328	static int coda_rmdir(struct inode dir, struct dentry de)
1da177e4 LT	329	{
	330	const char *name = de->d_name.name;
	331	int len = de->d_name.len;
8c6d2152	332	int error;
1da177e4	333
1da177e4	334	error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
8c6d2152 JH	335	if (!error) {
	336	/* VFS may delete the child */
	337	if (de->d_inode)
6d6b77f1	338	clear_nlink(de->d_inode);
1da177e4	339
8c6d2152 JH	340	/* fix the link count of the parent */
	341	coda_dir_drop_nlink(dir);
	342	coda_dir_update_mtime(dir);
d728900c	343	}
8c6d2152	344	return error;
1da177e4 LT	345	}
	346
	347	/* rename */
d728900c	348	static int coda_rename(struct inode old_dir, struct dentry old_dentry,
1da177e4 LT	349	struct inode new_dir, struct dentry new_dentry)
1da177e4 LT	350	{
d728900c JH	351	const char *old_name = old_dentry->d_name.name;
d728900c JH	352	const char *new_name = new_dentry->d_name.name;
1da177e4 LT	353	int old_length = old_dentry->d_name.len;
1da177e4 LT	354	int new_length = new_dentry->d_name.len;
d728900c	355	int error;
1da177e4	356
d728900c JH	357	error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
d728900c JH	358	coda_i2f(new_dir), old_length, new_length,
1da177e4	359	(const char ) old_name, (const char )new_name);
f7cc02b8 YA	360	if (!error) {
	361	if (new_dentry->d_inode) {
	362	if (S_ISDIR(new_dentry->d_inode->i_mode)) {
d728900c JH	363	coda_dir_drop_nlink(old_dir);
	364	coda_dir_inc_nlink(new_dir);
	365	}
	366	coda_dir_update_mtime(old_dir);
	367	coda_dir_update_mtime(new_dir);
1da177e4 LT	368	coda_flag_inode(new_dentry->d_inode, C_VATTR);
	369	} else {
	370	coda_flag_inode(old_dir, C_VATTR);
	371	coda_flag_inode(new_dir, C_VATTR);
d728900c	372	}
1da177e4	373	}
1da177e4 LT	374	return error;
	375	}
	376
	377
	378	/* file operations for directories */
e924f251	379	static int coda_readdir(struct file coda_file, struct dir_context ctx)
1da177e4	380	{
1da177e4 LT	381	struct coda_file_info *cfi;
1da177e4 LT	382	struct file *host_file;
1da177e4 LT	383	int ret;
	384
	385	cfi = CODA_FTOC(coda_file);
	386	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	387	host_file = cfi->cfi_container;
	388
e924f251	389	if (host_file->f_op->iterate) {
496ad9aa	390	struct inode *host_inode = file_inode(host_file);
bb6f619b AV	391	mutex_lock(&host_inode->i_mutex);
	392	ret = -ENOENT;
	393	if (!IS_DEADDIR(host_inode)) {
	394	ret = host_file->f_op->iterate(host_file, ctx);
	395	file_accessed(host_file);
	396	}
	397	mutex_unlock(&host_inode->i_mutex);
e924f251 AV	398	return ret;
	399	}
	400	/* Venus: we must read Venus dirents from a file */
	401	return coda_venus_readdir(coda_file, ctx);
1da177e4 LT	402	}
	403
	404	static inline unsigned int CDT2DT(unsigned char cdt)
	405	{
	406	unsigned int dt;
	407
	408	switch(cdt) {
	409	case CDT_UNKNOWN: dt = DT_UNKNOWN; break;
	410	case CDT_FIFO: dt = DT_FIFO; break;
	411	case CDT_CHR: dt = DT_CHR; break;
	412	case CDT_DIR: dt = DT_DIR; break;
	413	case CDT_BLK: dt = DT_BLK; break;
	414	case CDT_REG: dt = DT_REG; break;
	415	case CDT_LNK: dt = DT_LNK; break;
	416	case CDT_SOCK: dt = DT_SOCK; break;
	417	case CDT_WHT: dt = DT_WHT; break;
	418	default: dt = DT_UNKNOWN; break;
	419	}
	420	return dt;
	421	}
	422
	423	/* support routines */
e924f251	424	static int coda_venus_readdir(struct file coda_file, struct dir_context ctx)
1da177e4	425	{
97875253 JH	426	struct coda_file_info *cfi;
	427	struct coda_inode_info *cii;
	428	struct file *host_file;
1da177e4	429	struct venus_dirent *vdir;
ee60498f	430	unsigned long vdir_size = offsetof(struct venus_dirent, d_name);
1da177e4 LT	431	unsigned int type;
	432	struct qstr name;
	433	ino_t ino;
97875253 JH	434	int ret;
	435
	436	cfi = CODA_FTOC(coda_file);
	437	BUG_ON(!cfi \|\| cfi->cfi_magic != CODA_MAGIC);
	438	host_file = cfi->cfi_container;
	439
93fe74b2	440	cii = ITOC(file_inode(coda_file));
1da177e4	441
f52720ca	442	vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
1da177e4 LT	443	if (!vdir) return -ENOMEM;
1da177e4 LT	444
e924f251 AV	445	if (!dir_emit_dots(coda_file, ctx))
	446	goto out;
	447
1da177e4 LT	448	while (1) {
1da177e4 LT	449	/* read entries from the directory file */
e924f251	450	ret = kernel_read(host_file, ctx->pos - 2, (char *)vdir,
1da177e4 LT	451	sizeof(*vdir));
1da177e4 LT	452	if (ret < 0) {
6d6bd94f FF	453	pr_err("%s: read dir %s failed %d\n",
6d6bd94f FF	454	__func__, coda_f2s(&cii->c_fid), ret);
1da177e4 LT	455	break;
	456	}
	457	if (ret == 0) break; /* end of directory file reached */
	458
	459	/* catch truncated reads */
	460	if (ret < vdir_size \|\| ret < vdir_size + vdir->d_namlen) {
6d6bd94f FF	461	pr_err("%s: short read on %s\n",
6d6bd94f FF	462	__func__, coda_f2s(&cii->c_fid));
1da177e4 LT	463	ret = -EBADF;
	464	break;
	465	}
	466	/* validate whether the directory file actually makes sense */
	467	if (vdir->d_reclen < vdir_size + vdir->d_namlen) {
6d6bd94f FF	468	pr_err("%s: invalid dir %s\n",
6d6bd94f FF	469	__func__, coda_f2s(&cii->c_fid));
1da177e4 LT	470	ret = -EBADF;
	471	break;
	472	}
	473
	474	name.len = vdir->d_namlen;
	475	name.name = vdir->d_name;
	476
	477	/* Make sure we skip '.' and '..', we already got those */
	478	if (name.name[0] == '.' && (name.len == 1 \|\|
e924f251	479	(name.name[1] == '.' && name.len == 2)))
1da177e4 LT	480	vdir->d_fileno = name.len = 0;
	481
	482	/* skip null entries */
	483	if (vdir->d_fileno && name.len) {
6b5e1223	484	ino = vdir->d_fileno;
1da177e4	485	type = CDT2DT(vdir->d_type);
e924f251 AV	486	if (!dir_emit(ctx, name.name, name.len, ino, type))
e924f251 AV	487	break;
1da177e4 LT	488	}
	489	/* we'll always have progress because d_reclen is unsigned and
	490	* we've already established it is non-zero. */
e924f251	491	ctx->pos += vdir->d_reclen;
97875253	492	}
5f47c7ea	493	out:
1da177e4	494	kfree(vdir);
e924f251	495	return 0;
1da177e4 LT	496	}
	497
	498	/* called when a cache lookup succeeds */
0b728e19	499	static int coda_dentry_revalidate(struct dentry *de, unsigned int flags)
1da177e4	500	{
34286d66	501	struct inode *inode;
1da177e4 LT	502	struct coda_inode_info *cii;
1da177e4 LT	503
0b728e19	504	if (flags & LOOKUP_RCU)
34286d66 NP	505	return -ECHILD;
	506
	507	inode = de->d_inode;
a7400222	508	if (!inode \|\| is_root_inode(inode))
1da177e4 LT	509	goto out;
	510	if (is_bad_inode(inode))
	511	goto bad;
	512
	513	cii = ITOC(de->d_inode);
	514	if (!(cii->c_flags & (C_PURGE \| C_FLUSH)))
	515	goto out;
	516
	517	shrink_dcache_parent(de);
	518
	519	/* propagate for a flush */
	520	if (cii->c_flags & C_FLUSH)
	521	coda_flag_inode_children(inode, C_FLUSH);
	522
84d08fa8	523	if (d_count(de) > 1)
1da177e4 LT	524	/* pretend it's valid, but don't change the flags */
	525	goto out;
	526
	527	/* clear the flags. */
b5ce1d83	528	spin_lock(&cii->c_lock);
1da177e4	529	cii->c_flags &= ~(C_VATTR \| C_PURGE \| C_FLUSH);
b5ce1d83	530	spin_unlock(&cii->c_lock);
1da177e4	531	bad:
1da177e4 LT	532	return 0;
1da177e4 LT	533	out:
1da177e4 LT	534	return 1;
	535	}
	536
	537	/*
	538	* This is the callback from dput() when d_count is going to 0.
	539	* We use this to unhash dentries with bad inodes.
	540	*/
fe15ce44	541	static int coda_dentry_delete(const struct dentry * dentry)
1da177e4 LT	542	{
	543	int flags;
	544
	545	if (!dentry->d_inode)
	546	return 0;
	547
	548	flags = (ITOC(dentry->d_inode)->c_flags) & C_PURGE;
	549	if (is_bad_inode(dentry->d_inode) \|\| flags) {
	550	return 1;
	551	}
	552	return 0;
	553	}
	554
	555
	556
	557	/*
	558	* This is called when we want to check if the inode has
	559	* changed on the server. Coda makes this easy since the
	560	* cache manager Venus issues a downcall to the kernel when this
	561	* happens
	562	*/
11d100d9	563	int coda_revalidate_inode(struct inode *inode)
1da177e4 LT	564	{
1da177e4 LT	565	struct coda_vattr attr;
f7cc02b8	566	int error;
1da177e4 LT	567	int old_mode;
1da177e4 LT	568	ino_t old_ino;
1da177e4 LT	569	struct coda_inode_info *cii = ITOC(inode);
1da177e4 LT	570
f7cc02b8 YA	571	if (!cii->c_flags)
f7cc02b8 YA	572	return 0;
1da177e4 LT	573
	574	if (cii->c_flags & (C_VATTR \| C_PURGE \| C_FLUSH)) {
	575	error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr);
f7cc02b8 YA	576	if (error)
f7cc02b8 YA	577	return -EIO;
1da177e4 LT	578
	579	/* this inode may be lost if:
	580	- it's ino changed
	581	- type changes must be permitted for repair and
	582	missing mount points.
	583	*/
	584	old_mode = inode->i_mode;
	585	old_ino = inode->i_ino;
	586	coda_vattr_to_iattr(inode, &attr);
	587
	588	if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) {
f38cfb25	589	pr_warn("inode %ld, fid %s changed type!\n",
d9b4b319	590	inode->i_ino, coda_f2s(&(cii->c_fid)));
1da177e4 LT	591	}
	592
	593	/* the following can happen when a local fid is replaced
	594	with a global one, here we lose and declare the inode bad */
	595	if (inode->i_ino != old_ino)
f7cc02b8	596	return -EIO;
1da177e4 LT	597
1da177e4 LT	598	coda_flag_inode_children(inode, C_FLUSH);
b5ce1d83 YA	599
b5ce1d83 YA	600	spin_lock(&cii->c_lock);
1da177e4	601	cii->c_flags &= ~(C_VATTR \| C_PURGE \| C_FLUSH);
b5ce1d83	602	spin_unlock(&cii->c_lock);
1da177e4	603	}
1da177e4	604	return 0;
1da177e4	605	}