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| author | Al Viro <viro@zeniv.linux.org.uk> | 2012-01-10 22:20:12 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-01-11 00:19:12 -0500 |
| commit | 4041bcdc7bef06a2fb29c57394c713a74bd13b08 (patch) | |
| tree | adaf5dee1b8312cdd37a2b37551770af461212a3 /fs/autofs4 | |
| parent | b3f2a92447b8443360ac117a3d7c06689562a70c (diff) | |
| download | linux-4041bcdc7bef06a2fb29c57394c713a74bd13b08.tar.gz linux-4041bcdc7bef06a2fb29c57394c713a74bd13b08.tar.bz2 linux-4041bcdc7bef06a2fb29c57394c713a74bd13b08.zip | |
autofs4: autofs4_wait() vs. autofs4_catatonic_mode() race
We need to recheck ->catatonic after autofs4_wait() got ->wq_mutex
for good, or we might end up with wq inserted into queue after
autofs4_catatonic_mode() had done its thing. It will stick there
forever, since there won't be anything to clear its ->name.name.
A bit of a complication: validate_request() drops and regains ->wq_mutex.
It actually ends up the most convenient place to stick the check into...
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/autofs4')
| -rw-r--r-- | fs/autofs4/waitq.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c index e1fbdeef85db..c13273afd546 100644 --- a/fs/autofs4/waitq.c +++ b/fs/autofs4/waitq.c @@ -257,6 +257,9 @@ static int validate_request(struct autofs_wait_queue **wait, struct autofs_wait_queue *wq; struct autofs_info *ino; + if (sbi->catatonic) + return -ENOENT; + /* Wait in progress, continue; */ wq = autofs4_find_wait(sbi, qstr); if (wq) { @@ -289,6 +292,9 @@ static int validate_request(struct autofs_wait_queue **wait, if (mutex_lock_interruptible(&sbi->wq_mutex)) return -EINTR; + if (sbi->catatonic) + return -ENOENT; + wq = autofs4_find_wait(sbi, qstr); if (wq) { *wait = wq; @@ -389,7 +395,7 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry, ret = validate_request(&wq, sbi, &qstr, dentry, notify); if (ret <= 0) { - if (ret == 0) + if (ret != -EINTR) mutex_unlock(&sbi->wq_mutex); kfree(qstr.name); return ret; |