>From 57c070ec9322815caaa33f4a669b86fac9002075 Mon Sep 17 00:00:00 2001
From: Steven Whitehouse <[email protected]>
Date: Thu, 25 Jan 2007 17:14:59 +0000
Subject: [PATCH] [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 <[email protected]>
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index f7c8d31..88fcfb4 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)
diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index 747c731..5591f89 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -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;
--
1.4.4.2
-
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