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authorRussell King <rmk@dyn-67.arm.linux.org.uk>2008-10-07 19:08:56 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2008-10-07 19:08:56 +0100
commit5a89770daad83df74d77a8d34a1ffaedae565ce9 (patch)
tree0d8ef70293a6ef969ba8b7718e59608337643d40 /Documentation/filesystems/Locking
parentc46c948260f41af18b277c1eb1895d788d3605dc (diff)
parentaf7c951d76708c61b862463d579d76be757130bf (diff)
downloadblackbird-op-linux-5a89770daad83df74d77a8d34a1ffaedae565ce9.tar.gz
blackbird-op-linux-5a89770daad83df74d77a8d34a1ffaedae565ce9.zip
Merge branches 'pxa-core' and 'pxa-machines' into pxa-all
Conflicts: arch/arm/mach-pxa/Kconfig arch/arm/mach-pxa/pxa25x.c arch/arm/mach-pxa/pxa27x.c
Diffstat (limited to 'Documentation/filesystems/Locking')
-rw-r--r--Documentation/filesystems/Locking15
1 files changed, 4 insertions, 11 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 680fb566b928..8362860e21a7 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -144,8 +144,8 @@ prototypes:
void (*kill_sb) (struct super_block *);
locking rules:
may block BKL
-get_sb yes yes
-kill_sb yes yes
+get_sb yes no
+kill_sb yes no
->get_sb() returns error or 0 with locked superblock attached to the vfsmount
(exclusive on ->s_umount).
@@ -409,12 +409,12 @@ ioctl: yes (see below)
unlocked_ioctl: no (see below)
compat_ioctl: no
mmap: no
-open: maybe (see below)
+open: no
flush: no
release: no
fsync: no (see below)
aio_fsync: no
-fasync: yes (see below)
+fasync: no
lock: yes
readv: no
writev: no
@@ -431,13 +431,6 @@ For many filesystems, it is probably safe to acquire the inode
semaphore. Note some filesystems (i.e. remote ones) provide no
protection for i_size so you will need to use the BKL.
-->open() locking is in-transit: big lock partially moved into the methods.
-The only exception is ->open() in the instances of file_operations that never
-end up in ->i_fop/->proc_fops, i.e. ones that belong to character devices
-(chrdev_open() takes lock before replacing ->f_op and calling the secondary
-method. As soon as we fix the handling of module reference counters all
-instances of ->open() will be called without the BKL.
-
Note: ext2_release() was *the* source of contention on fs-intensive
loads and dropping BKL on ->release() helps to get rid of that (we still
grab BKL for cases when we close a file that had been opened r/w, but that
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