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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-27 12:38:12 -0400 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2010-10-27 22:06:17 +0200 |
| commit | f7347ce4ee7c65415f84be915c018473e7076f31 (patch) | |
| tree | 613ce14f088ad00bdbc77cdfb686a40a4851180f /include/linux/fs.h | |
| parent | c5b1f0d92c36851aca09ac6c7c0c4f9690ac14f3 (diff) | |
| download | blackbird-op-linux-f7347ce4ee7c65415f84be915c018473e7076f31.tar.gz blackbird-op-linux-f7347ce4ee7c65415f84be915c018473e7076f31.zip | |
fasync: re-organize fasync entry insertion to allow it under a spinlock
You currently cannot use "fasync_helper()" in an atomic environment to
insert a new fasync entry, because it will need to allocate the new
"struct fasync_struct".
Yet fcntl_setlease() wants to call this under lock_flocks(), which is in
the process of being converted from the BKL to a spinlock.
In order to fix this, this abstracts out the actual fasync list
insertion and the fasync allocations into functions of their own, and
teaches fs/locks.c to pre-allocate the fasync_struct entry. That way
the actual list insertion can happen while holding the required
spinlock.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bfields@redhat.com: rebase on top of my changes to Arnd's patch]
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'include/linux/fs.h')
| -rw-r--r-- | include/linux/fs.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 8d7de08ab546..56285e5e1de4 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1302,6 +1302,11 @@ struct fasync_struct { /* SMP safe fasync helpers: */ extern int fasync_helper(int, struct file *, int, struct fasync_struct **); +extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *); +extern int fasync_remove_entry(struct file *, struct fasync_struct **); +extern struct fasync_struct *fasync_alloc(void); +extern void fasync_free(struct fasync_struct *); + /* can be called from interrupts */ extern void kill_fasync(struct fasync_struct **, int, int); |
