[mirror_ubuntu-artful-kernel.git] / fs / coda / cnode.c

/* cnode related routines for the coda kernel code
   (C) 1996 Peter Braam
   */

#include <linux/types.h>
#include <linux/string.h>
#include <linux/time.h>

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

static inline int coda_fideq(struct CodaFid *fid1, struct CodaFid *fid2)
{
	return memcmp(fid1, fid2, sizeof(*fid1)) == 0;
}

static const struct inode_operations coda_symlink_inode_operations = {
	.get_link	= page_get_link,
	.setattr	= coda_setattr,
};

/* cnode.c */
static void coda_fill_inode(struct inode *inode, struct coda_vattr *attr)
{
        coda_vattr_to_iattr(inode, attr);

        if (S_ISREG(inode->i_mode)) {
                inode->i_op = &coda_file_inode_operations;
                inode->i_fop = &coda_file_operations;
        } else if (S_ISDIR(inode->i_mode)) {
                inode->i_op = &coda_dir_inode_operations;
                inode->i_fop = &coda_dir_operations;
        } else if (S_ISLNK(inode->i_mode)) {
		inode->i_op = &coda_symlink_inode_operations;
		inode_nohighmem(inode);
		inode->i_data.a_ops = &coda_symlink_aops;
		inode->i_mapping = &inode->i_data;
	} else
                init_special_inode(inode, inode->i_mode, huge_decode_dev(attr->va_rdev));
}

static int coda_test_inode(struct inode *inode, void *data)
{
	struct CodaFid *fid = (struct CodaFid *)data;
	struct coda_inode_info *cii = ITOC(inode);
	return coda_fideq(&cii->c_fid, fid);
}

static int coda_set_inode(struct inode *inode, void *data)
{
	struct CodaFid *fid = (struct CodaFid *)data;
	struct coda_inode_info *cii = ITOC(inode);
	cii->c_fid = *fid;
	return 0;
}

struct inode * coda_iget(struct super_block * sb, struct CodaFid * fid,
			 struct coda_vattr * attr)
{
	struct inode *inode;
	struct coda_inode_info *cii;
	unsigned long hash = coda_f2i(fid);

	inode = iget5_locked(sb, hash, coda_test_inode, coda_set_inode, fid);

	if (!inode)
		return ERR_PTR(-ENOMEM);

	if (inode->i_state & I_NEW) {
		cii = ITOC(inode);
		/* we still need to set i_ino for things like stat(2) */
		inode->i_ino = hash;
		/* inode is locked and unique, no need to grab cii->c_lock */
		cii->c_mapcount = 0;
		unlock_new_inode(inode);
	}

	/* always replace the attributes, type might have changed */
	coda_fill_inode(inode, attr);
	return inode;
}

/* this is effectively coda_iget:
   - get attributes (might be cached)
   - get the inode for the fid using vfs iget
   - link the two up if this is needed
   - fill in the attributes
*/
struct inode *coda_cnode_make(struct CodaFid *fid, struct super_block *sb)
{
        struct coda_vattr attr;
	struct inode *inode;
        int error;
        
	/* We get inode numbers from Venus -- see venus source */
	error = venus_getattr(sb, fid, &attr);
	if (error)
		return ERR_PTR(error);

	inode = coda_iget(sb, fid, &attr);
	if (IS_ERR(inode))
		pr_warn("%s: coda_iget failed\n", __func__);
	return inode;
}


/* Although we treat Coda file identifiers as immutable, there is one
 * special case for files created during a disconnection where they may
 * not be globally unique. When an identifier collision is detected we
 * first try to flush the cached inode from the kernel and finally
 * resort to renaming/rehashing in-place. Userspace remembers both old
 * and new values of the identifier to handle any in-flight upcalls.
 * The real solution is to use globally unique UUIDs as identifiers, but
 * retrofitting the existing userspace code for this is non-trivial. */
void coda_replace_fid(struct inode *inode, struct CodaFid *oldfid, 
		      struct CodaFid *newfid)
{
	struct coda_inode_info *cii = ITOC(inode);
	unsigned long hash = coda_f2i(newfid);
	
	BUG_ON(!coda_fideq(&cii->c_fid, oldfid));

	/* replace fid and rehash inode */
	/* XXX we probably need to hold some lock here! */
	remove_inode_hash(inode);
	cii->c_fid = *newfid;
	inode->i_ino = hash;
	__insert_inode_hash(inode, hash);
}

/* convert a fid to an inode. */
struct inode *coda_fid_to_inode(struct CodaFid *fid, struct super_block *sb) 
{
	struct inode *inode;
	unsigned long hash = coda_f2i(fid);

	if ( !sb ) {
		pr_warn("%s: no sb!\n", __func__);
		return NULL;
	}

	inode = ilookup5(sb, hash, coda_test_inode, fid);
	if ( !inode )
		return NULL;

	/* we should never see newly created inodes because we intentionally
	 * fail in the initialization callback */
	BUG_ON(inode->i_state & I_NEW);

	return inode;
}

/* the CONTROL inode is made without asking attributes from Venus */
struct inode *coda_cnode_makectl(struct super_block *sb)
{
	struct inode *inode = new_inode(sb);
	if (inode) {
		inode->i_ino = CTL_INO;
		inode->i_op = &coda_ioctl_inode_operations;
		inode->i_fop = &coda_ioctl_operations;
		inode->i_mode = 0444;
		return inode;
	}
	return ERR_PTR(-ENOMEM);
}
Commit	Line	Data
1da177e4 LT	1	/* cnode related routines for the coda kernel code
	2	(C) 1996 Peter Braam
	3	*/
	4
	5	#include <linux/types.h>
	6	#include <linux/string.h>
	7	#include <linux/time.h>
	8
	9	#include <linux/coda.h>
1da177e4	10	#include <linux/coda_psdev.h>
21fc61c7	11	#include <linux/pagemap.h>
31a203df	12	#include "coda_linux.h"
1da177e4 LT	13
	14	static inline int coda_fideq(struct CodaFid fid1, struct CodaFid fid2)
	15	{
	16	return memcmp(fid1, fid2, sizeof(*fid1)) == 0;
	17	}
	18
754661f1	19	static const struct inode_operations coda_symlink_inode_operations = {
6b255391	20	.get_link = page_get_link,
1da177e4 LT	21	.setattr = coda_setattr,
	22	};
	23
	24	/* cnode.c */
	25	static void coda_fill_inode(struct inode inode, struct coda_vattr attr)
	26	{
	27	coda_vattr_to_iattr(inode, attr);
	28
	29	if (S_ISREG(inode->i_mode)) {
	30	inode->i_op = &coda_file_inode_operations;
	31	inode->i_fop = &coda_file_operations;
	32	} else if (S_ISDIR(inode->i_mode)) {
	33	inode->i_op = &coda_dir_inode_operations;
	34	inode->i_fop = &coda_dir_operations;
	35	} else if (S_ISLNK(inode->i_mode)) {
	36	inode->i_op = &coda_symlink_inode_operations;
21fc61c7	37	inode_nohighmem(inode);
1da177e4 LT	38	inode->i_data.a_ops = &coda_symlink_aops;
	39	inode->i_mapping = &inode->i_data;
	40	} else
	41	init_special_inode(inode, inode->i_mode, huge_decode_dev(attr->va_rdev));
	42	}
	43
	44	static int coda_test_inode(struct inode inode, void data)
	45	{
	46	struct CodaFid fid = (struct CodaFid )data;
b5ce1d83 YA	47	struct coda_inode_info *cii = ITOC(inode);
b5ce1d83 YA	48	return coda_fideq(&cii->c_fid, fid);
1da177e4 LT	49	}
	50
	51	static int coda_set_inode(struct inode inode, void data)
	52	{
	53	struct CodaFid fid = (struct CodaFid )data;
b5ce1d83 YA	54	struct coda_inode_info *cii = ITOC(inode);
b5ce1d83 YA	55	cii->c_fid = *fid;
1da177e4 LT	56	return 0;
	57	}
	58
1da177e4 LT	59	struct inode * coda_iget(struct super_block * sb, struct CodaFid * fid,
	60	struct coda_vattr * attr)
	61	{
	62	struct inode *inode;
	63	struct coda_inode_info *cii;
	64	unsigned long hash = coda_f2i(fid);
	65
	66	inode = iget5_locked(sb, hash, coda_test_inode, coda_set_inode, fid);
	67
	68	if (!inode)
	69	return ERR_PTR(-ENOMEM);
	70
	71	if (inode->i_state & I_NEW) {
	72	cii = ITOC(inode);
	73	/* we still need to set i_ino for things like stat(2) */
	74	inode->i_ino = hash;
b5ce1d83	75	/* inode is locked and unique, no need to grab cii->c_lock */
1da177e4 LT	76	cii->c_mapcount = 0;
	77	unlock_new_inode(inode);
	78	}
	79
	80	/* always replace the attributes, type might have changed */
	81	coda_fill_inode(inode, attr);
	82	return inode;
	83	}
	84
	85	/* this is effectively coda_iget:
	86	- get attributes (might be cached)
	87	- get the inode for the fid using vfs iget
	88	- link the two up if this is needed
	89	- fill in the attributes
	90	*/
f4947fbc	91	struct inode coda_cnode_make(struct CodaFid fid, struct super_block *sb)
1da177e4 LT	92	{
1da177e4 LT	93	struct coda_vattr attr;
f4947fbc	94	struct inode *inode;
1da177e4 LT	95	int error;
	96
	97	/* We get inode numbers from Venus -- see venus source */
	98	error = venus_getattr(sb, fid, &attr);
f4947fbc AV	99	if (error)
f4947fbc AV	100	return ERR_PTR(error);
1da177e4	101
f4947fbc AV	102	inode = coda_iget(sb, fid, &attr);
f4947fbc AV	103	if (IS_ERR(inode))
6d6bd94f	104	pr_warn("%s: coda_iget failed\n", __func__);
f4947fbc	105	return inode;
1da177e4 LT	106	}
	107
	108
b5ce1d83 YA	109	/* Although we treat Coda file identifiers as immutable, there is one
	110	* special case for files created during a disconnection where they may
	111	* not be globally unique. When an identifier collision is detected we
	112	* first try to flush the cached inode from the kernel and finally
	113	* resort to renaming/rehashing in-place. Userspace remembers both old
	114	* and new values of the identifier to handle any in-flight upcalls.
	115	* The real solution is to use globally unique UUIDs as identifiers, but
	116	* retrofitting the existing userspace code for this is non-trivial. */
1da177e4 LT	117	void coda_replace_fid(struct inode inode, struct CodaFid oldfid,
	118	struct CodaFid *newfid)
	119	{
b5ce1d83	120	struct coda_inode_info *cii = ITOC(inode);
1da177e4 LT	121	unsigned long hash = coda_f2i(newfid);
1da177e4 LT	122
c5d3237c	123	BUG_ON(!coda_fideq(&cii->c_fid, oldfid));
1da177e4 LT	124
	125	/* replace fid and rehash inode */
	126	/* XXX we probably need to hold some lock here! */
	127	remove_inode_hash(inode);
	128	cii->c_fid = *newfid;
	129	inode->i_ino = hash;
	130	__insert_inode_hash(inode, hash);
	131	}
	132
	133	/* convert a fid to an inode. */
	134	struct inode coda_fid_to_inode(struct CodaFid fid, struct super_block *sb)
	135	{
	136	struct inode *inode;
	137	unsigned long hash = coda_f2i(fid);
	138
	139	if ( !sb ) {
6d6bd94f	140	pr_warn("%s: no sb!\n", __func__);
1da177e4 LT	141	return NULL;
	142	}
	143
ed31a7dd	144	inode = ilookup5(sb, hash, coda_test_inode, fid);
1da177e4 LT	145	if ( !inode )
	146	return NULL;
	147
	148	/* we should never see newly created inodes because we intentionally
	149	* fail in the initialization callback */
	150	BUG_ON(inode->i_state & I_NEW);
	151
	152	return inode;
	153	}
	154
	155	/* the CONTROL inode is made without asking attributes from Venus */
0b2c4e39	156	struct inode coda_cnode_makectl(struct super_block sb)
1da177e4	157	{
0b2c4e39 AV	158	struct inode *inode = new_inode(sb);
	159	if (inode) {
	160	inode->i_ino = CTL_INO;
	161	inode->i_op = &coda_ioctl_inode_operations;
	162	inode->i_fop = &coda_ioctl_operations;
	163	inode->i_mode = 0444;
	164	return inode;
1da177e4	165	}
0b2c4e39	166	return ERR_PTR(-ENOMEM);
1da177e4 LT	167	}
1da177e4 LT	168