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-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