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| author | Boaz Harrosh <bharrosh@panasas.com> | 2011-02-10 15:01:20 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-02-11 16:12:19 -0800 |
| commit | d863b50ab01333659314c2034890cb76d9fdc3c7 (patch) | |
| tree | 88d27ed4717bb49ba696f2efb5ef024388412af3 /fs/super.c | |
| parent | 2dab597441667d6c04451a7dcf215241ad4c74f6 (diff) | |
| download | linux-stable-d863b50ab01333659314c2034890cb76d9fdc3c7.tar.gz linux-stable-d863b50ab01333659314c2034890cb76d9fdc3c7.tar.bz2 linux-stable-d863b50ab01333659314c2034890cb76d9fdc3c7.zip | |
vfs: call rcu_barrier after ->kill_sb()
In commit fa0d7e3de6d6 ("fs: icache RCU free inodes"), we use rcu free
inode instead of freeing the inode directly. It causes a crash when we
rmmod immediately after we umount the volume[1].
So we need to call rcu_barrier after we kill_sb so that the inode is
freed before we do rmmod. The idea is inspired by Aneesh Kumar.
rcu_barrier will wait for all callbacks to end before preceding. The
original patch was done by Tao Ma, but synchronize_rcu() is not enough
here.
1. http://marc.info/?l=linux-fsdevel&m=129680863330185&w=2
Tested-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/super.c')
| -rw-r--r-- | fs/super.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/super.c b/fs/super.c index 74e149efed81..7e9dd4cc2c01 100644 --- a/fs/super.c +++ b/fs/super.c @@ -177,6 +177,11 @@ void deactivate_locked_super(struct super_block *s) struct file_system_type *fs = s->s_type; if (atomic_dec_and_test(&s->s_active)) { fs->kill_sb(s); + /* + * We need to call rcu_barrier so all the delayed rcu free + * inodes are flushed before we release the fs module. + */ + rcu_barrier(); put_filesystem(fs); put_super(s); } else { |