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| author | Steven Whitehouse <swhiteho@redhat.com> | 2007-01-25 17:14:59 +0000 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2007-02-05 13:37:53 -0500 |
| commit | d7c103d0bd29c94f78155a4538faf314e49d9713 (patch) | |
| tree | 62c453ffe7d6d4637aa93dd43dbb0665175f644c /fs/gfs2/inode.c | |
| parent | b790c3b7c38aae28c497bb363a6fe72f7c96568f (diff) | |
| download | lwn-d7c103d0bd29c94f78155a4538faf314e49d9713.tar.gz lwn-d7c103d0bd29c94f78155a4538faf314e49d9713.zip | |
[GFS2] Fix recursive locking attempt with NFS
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>
Diffstat (limited to 'fs/gfs2/inode.c')
| -rw-r--r-- | fs/gfs2/inode.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c index f7c8d31ce41a..88fcfb4f5c4d 100644 --- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -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) |