[net-next-2.6.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_linux.h>
#include <linux/coda_fs_i.h>
#include <linux/coda_psdev.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 = {
	.readlink	= generic_readlink,
	.follow_link	= page_follow_link_light,
	.put_link	= page_put_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->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
*/
int coda_cnode_make(struct inode **inode, struct CodaFid *fid, struct super_block *sb)
{
        struct coda_vattr attr;
        int error;
        
	/* We get inode numbers from Venus -- see venus source */
	error = venus_getattr(sb, fid, &attr);
	if ( error ) {
	    *inode = NULL;
	    return error;
	} 

	*inode = coda_iget(sb, fid, &attr);
	if ( IS_ERR(*inode) ) {
		printk("coda_cnode_make: coda_iget failed\n");
                return PTR_ERR(*inode);
        }
	return 0;
}


/* 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 ) {
		printk("coda_fid_to_inode: no sb!\n");
		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 */
int coda_cnode_makectl(struct inode **inode, struct super_block *sb)
{
	int error = -ENOMEM;

	*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;
		error = 0;
	}

	return error;
}
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>
	10	#include <linux/coda_linux.h>
	11	#include <linux/coda_fs_i.h>
	12	#include <linux/coda_psdev.h>
	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 = {
1da177e4 LT	20	.readlink = generic_readlink,
	21	.follow_link = page_follow_link_light,
	22	.put_link = page_put_link,
	23	.setattr = coda_setattr,
	24	};
	25
	26	/* cnode.c */
	27	static void coda_fill_inode(struct inode inode, struct coda_vattr attr)
	28	{
	29	coda_vattr_to_iattr(inode, attr);
	30
	31	if (S_ISREG(inode->i_mode)) {
	32	inode->i_op = &coda_file_inode_operations;
	33	inode->i_fop = &coda_file_operations;
	34	} else if (S_ISDIR(inode->i_mode)) {
	35	inode->i_op = &coda_dir_inode_operations;
	36	inode->i_fop = &coda_dir_operations;
	37	} else if (S_ISLNK(inode->i_mode)) {
	38	inode->i_op = &coda_symlink_inode_operations;
	39	inode->i_data.a_ops = &coda_symlink_aops;
	40	inode->i_mapping = &inode->i_data;
	41	} else
	42	init_special_inode(inode, inode->i_mode, huge_decode_dev(attr->va_rdev));
	43	}
	44
	45	static int coda_test_inode(struct inode inode, void data)
	46	{
	47	struct CodaFid fid = (struct CodaFid )data;
b5ce1d83 YA	48	struct coda_inode_info *cii = ITOC(inode);
b5ce1d83 YA	49	return coda_fideq(&cii->c_fid, fid);
1da177e4 LT	50	}
	51
	52	static int coda_set_inode(struct inode inode, void data)
	53	{
	54	struct CodaFid fid = (struct CodaFid )data;
b5ce1d83 YA	55	struct coda_inode_info *cii = ITOC(inode);
b5ce1d83 YA	56	cii->c_fid = *fid;
1da177e4 LT	57	return 0;
	58	}
	59
1da177e4 LT	60	struct inode * coda_iget(struct super_block * sb, struct CodaFid * fid,
	61	struct coda_vattr * attr)
	62	{
	63	struct inode *inode;
	64	struct coda_inode_info *cii;
	65	unsigned long hash = coda_f2i(fid);
	66
	67	inode = iget5_locked(sb, hash, coda_test_inode, coda_set_inode, fid);
	68
	69	if (!inode)
	70	return ERR_PTR(-ENOMEM);
	71
	72	if (inode->i_state & I_NEW) {
	73	cii = ITOC(inode);
	74	/* we still need to set i_ino for things like stat(2) */
	75	inode->i_ino = hash;
b5ce1d83	76	/* inode is locked and unique, no need to grab cii->c_lock */
1da177e4 LT	77	cii->c_mapcount = 0;
	78	unlock_new_inode(inode);
	79	}
	80
	81	/* always replace the attributes, type might have changed */
	82	coda_fill_inode(inode, attr);
	83	return inode;
	84	}
	85
	86	/* this is effectively coda_iget:
	87	- get attributes (might be cached)
	88	- get the inode for the fid using vfs iget
	89	- link the two up if this is needed
	90	- fill in the attributes
	91	*/
	92	int coda_cnode_make(struct inode *inode, struct CodaFid fid, struct super_block *sb)
	93	{
	94	struct coda_vattr attr;
	95	int error;
	96
	97	/* We get inode numbers from Venus -- see venus source */
	98	error = venus_getattr(sb, fid, &attr);
	99	if ( error ) {
	100	*inode = NULL;
	101	return error;
	102	}
	103
	104	*inode = coda_iget(sb, fid, &attr);
	105	if ( IS_ERR(*inode) ) {
	106	printk("coda_cnode_make: coda_iget failed\n");
	107	return PTR_ERR(*inode);
	108	}
	109	return 0;
	110	}
	111
	112
b5ce1d83 YA	113	/* Although we treat Coda file identifiers as immutable, there is one
	114	* special case for files created during a disconnection where they may
	115	* not be globally unique. When an identifier collision is detected we
	116	* first try to flush the cached inode from the kernel and finally
	117	* resort to renaming/rehashing in-place. Userspace remembers both old
	118	* and new values of the identifier to handle any in-flight upcalls.
	119	* The real solution is to use globally unique UUIDs as identifiers, but
	120	* retrofitting the existing userspace code for this is non-trivial. */
1da177e4 LT	121	void coda_replace_fid(struct inode inode, struct CodaFid oldfid,
	122	struct CodaFid *newfid)
	123	{
b5ce1d83	124	struct coda_inode_info *cii = ITOC(inode);
1da177e4 LT	125	unsigned long hash = coda_f2i(newfid);
1da177e4 LT	126
c5d3237c	127	BUG_ON(!coda_fideq(&cii->c_fid, oldfid));
1da177e4 LT	128
	129	/* replace fid and rehash inode */
	130	/* XXX we probably need to hold some lock here! */
	131	remove_inode_hash(inode);
	132	cii->c_fid = *newfid;
	133	inode->i_ino = hash;
	134	__insert_inode_hash(inode, hash);
	135	}
	136
	137	/* convert a fid to an inode. */
	138	struct inode coda_fid_to_inode(struct CodaFid fid, struct super_block *sb)
	139	{
	140	struct inode *inode;
	141	unsigned long hash = coda_f2i(fid);
	142
	143	if ( !sb ) {
	144	printk("coda_fid_to_inode: no sb!\n");
	145	return NULL;
	146	}
	147
ed31a7dd	148	inode = ilookup5(sb, hash, coda_test_inode, fid);
1da177e4 LT	149	if ( !inode )
	150	return NULL;
	151
	152	/* we should never see newly created inodes because we intentionally
	153	* fail in the initialization callback */
	154	BUG_ON(inode->i_state & I_NEW);
	155
	156	return inode;
	157	}
	158
	159	/* the CONTROL inode is made without asking attributes from Venus */
	160	int coda_cnode_makectl(struct inode *inode, struct super_block sb)
	161	{
	162	int error = -ENOMEM;
	163
	164	*inode = new_inode(sb);
	165	if (*inode) {
	166	(*inode)->i_ino = CTL_INO;
	167	(*inode)->i_op = &coda_ioctl_inode_operations;
	168	(*inode)->i_fop = &coda_ioctl_operations;
	169	(*inode)->i_mode = 0444;
	170	error = 0;
	171	}
	172
	173	return error;
	174	}
	175