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[GFS2] Fix recursive locking attempt with NFS

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In certain cases, its possible for NFS to call the lookup code while
holding the glock (when doing a readdirplus operation) so we need to
check for that and not try and lock the glock twice. This also fixes a
typo in a previous NFS related GFS2 patch.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
This commit is contained in:
Steven Whitehouse 2007-01-25 17:14:59 +00:00
parent b790c3b7c3
commit d7c103d0bd
2 changed files with 16 additions and 9 deletions
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23
fs/gfs2/inode.c
View File

@ -395,8 +395,10 @@ struct inode *gfs2_lookup_simple(struct inode *dip, const char *name)
* @is_root: If 1, ignore the caller's permissions
* @i_gh: An uninitialized holder for the new inode glock
*
* There will always be a vnode (Linux VFS inode) for the d_gh inode unless
* @is_root is true.
* This can be called via the VFS filldir function when NFS is doing
* a readdirplus and the inode which its intending to stat isn't
* already in cache. In this case we must not take the directory glock
* again, since the readdir call will have already taken that lock.
*
* Returns: errno
*/
@ -409,8 +411,9 @@ struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
struct gfs2_holder d_gh;
struct gfs2_inum_host inum;
unsigned int type;
int error = 0;
int error;
struct inode *inode = NULL;
int unlock = 0;
if (!name->len || name->len > GFS2_FNAMESIZE)
return ERR_PTR(-ENAMETOOLONG);
@ -422,9 +425,12 @@ struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
return dir;
}
error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
if (error)
return ERR_PTR(error);
if (gfs2_glock_is_locked_by_me(dip->i_gl) == 0) {
error = gfs2_glock_nq_init(dip->i_gl, LM_ST_SHARED, 0, &d_gh);
if (error)
return ERR_PTR(error);
unlock = 1;
}
if (!is_root) {
error = permission(dir, MAY_EXEC, NULL);
@ -439,10 +445,11 @@ struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
inode = gfs2_inode_lookup(sb, &inum, type);
out:
gfs2_glock_dq_uninit(&d_gh);
if (unlock)
gfs2_glock_dq_uninit(&d_gh);
if (error == -ENOENT)
return NULL;
return inode;
return inode ? inode : ERR_PTR(error);
}
static int pick_formal_ino_1(struct gfs2_sbd *sdp, u64 *formal_ino)

2
fs/gfs2/ops_inode.c
View File

@ -1018,7 +1018,7 @@ static int gfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
}
generic_fillattr(inode, stat);
if (unlock);
if (unlock)
gfs2_glock_dq_uninit(&gh);
return 0;