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| author | Andy Adamson <andros@citi.umich.edu> | 2006-03-20 18:44:26 (GMT) |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2006-03-20 18:44:26 (GMT) |
| commit | 8dc7c3115b611c00006eac3ee5b108296432aab7 (patch) | |
| tree | be44c59907cbdcb6fdf46d0ad9cc140af757acfc /fs/nfs | |
| parent | 2e0af86f618c697b44e2d67dff151256c58201c4 (diff) | |
| download | linux-8dc7c3115b611c00006eac3ee5b108296432aab7.tar.xz | |
locks,lockd: fix race in nlmsvc_testlock
posix_test_lock() returns a pointer to a struct file_lock which is unprotected
and can be removed while in use by the caller. Move the conflicting lock from
the return to a parameter, and copy the conflicting lock.
In most cases the caller ends up putting the copy of the conflicting lock on
the stack. On i386, sizeof(struct file_lock) appears to be about 100 bytes.
We're assuming that's reasonable.
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs')
| -rw-r--r-- | fs/nfs/file.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 1cf07e4..ee140c5 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -392,15 +392,14 @@ out_swapfile: static int do_getlk(struct file *filp, int cmd, struct file_lock *fl) { - struct file_lock *cfl; + struct file_lock cfl; struct inode *inode = filp->f_mapping->host; int status = 0; lock_kernel(); /* Try local locking first */ - cfl = posix_test_lock(filp, fl); - if (cfl != NULL) { - locks_copy_lock(fl, cfl); + if (posix_test_lock(filp, fl, &cfl)) { + locks_copy_lock(fl, &cfl); goto out; } |