Commit b161dfa6 authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds

vfs: dcache: use DCACHE_DENTRY_KILLED instead of DCACHE_DISCONNECTED in d_kill()

IBM reported a soft lockup after applying the fix for the rename_lock
deadlock.  Commit c83ce989 ("VFS: Fix the nfs sillyrename regression
in kernel 2.6.38") was found to be the culprit.

The nfs sillyrename fix used DCACHE_DISCONNECTED to indicate that the
dentry was killed.  This flag can be set on non-killed dentries too,
which results in infinite retries when trying to traverse the dentry

This patch introduces a separate flag: DCACHE_DENTRY_KILLED, which is
only set in d_kill() and makes try_to_ascend() test only this flag.

IBM reported successful test results with this patch.
Signed-off-by: default avatarMiklos Szeredi <>
Cc: Trond Myklebust <>
Signed-off-by: default avatarLinus Torvalds <>
parent 4651afbb
......@@ -389,7 +389,7 @@ static struct dentry *d_kill(struct dentry *dentry, struct dentry *parent)
* Inform try_to_ascend() that we are no longer attached to the
* dentry tree
dentry->d_flags |= DCACHE_DISCONNECTED;
dentry->d_flags |= DCACHE_DENTRY_KILLED;
if (parent)
......@@ -1048,7 +1048,7 @@ static struct dentry *try_to_ascend(struct dentry *old, int locked, unsigned seq
* or deletion
if (new != old->d_parent ||
(old->d_flags & DCACHE_DISCONNECTED) ||
(old->d_flags & DCACHE_DENTRY_KILLED) ||
(!locked && read_seqretry(&rename_lock, seq))) {
new = NULL;
......@@ -206,6 +206,8 @@ struct dentry_operations {
#define DCACHE_DENTRY_KILLED 0x100000
extern seqlock_t rename_lock;
static inline int dname_external(struct dentry *dentry)
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