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| author | Ian Kent <raven@themaw.net> | 2008-07-23 21:30:26 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-24 10:47:32 -0700 |
| commit | 97e7449a7ad883bf9f516fc970778d75999c7843 (patch) | |
| tree | 903f6de243847eb12d1a372b271b15046ecdc774 /fs/autofs4/autofs_i.h | |
| parent | 26e81b3142f1ba497d4cd0365c13661684b784ce (diff) | |
| download | linux-97e7449a7ad883bf9f516fc970778d75999c7843.tar.gz linux-97e7449a7ad883bf9f516fc970778d75999c7843.tar.bz2 linux-97e7449a7ad883bf9f516fc970778d75999c7843.zip | |
autofs4: fix indirect mount pending expire race
The selection of a dentry for expiration and the setting of the
AUTOFS_INF_EXPIRING flag isn't done atomically which can lead to lookups
walking into an expiring mount.
What happens is that an expire is initiated by the daemon and a dentry is
selected for expire but, since there is no lock held between the selection
and setting of the expiring flag, a process may find the flag clear and
continue walking into the mount tree at the same time the daemon attempts
the expire it.
Signed-off-by: Ian Kent <raven@themaw.net>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/autofs4/autofs_i.h')
| -rw-r--r-- | fs/autofs4/autofs_i.h | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h index 058e1800caec..5d90ed3b4b43 100644 --- a/fs/autofs4/autofs_i.h +++ b/fs/autofs4/autofs_i.h @@ -138,18 +138,14 @@ static inline int autofs4_oz_mode(struct autofs_sb_info *sbi) { static inline int autofs4_ispending(struct dentry *dentry) { struct autofs_info *inf = autofs4_dentry_ino(dentry); - int pending = 0; if (dentry->d_flags & DCACHE_AUTOFS_PENDING) return 1; - if (inf) { - spin_lock(&inf->sbi->fs_lock); - pending = inf->flags & AUTOFS_INF_EXPIRING; - spin_unlock(&inf->sbi->fs_lock); - } + if (inf->flags & AUTOFS_INF_EXPIRING) + return 1; - return pending; + return 0; } static inline void autofs4_copy_atime(struct file *src, struct file *dst) |