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| author | Niu Yawei <yawei.niu@gmail.com> | 2013-02-01 21:31:27 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-04 06:09:05 +0800 |
| commit | fd80f53550720f200ca0469e9419c750f895ab50 (patch) | |
| tree | 9f38972a5c4df24ae1e780df97f5c85cffdbbf0f /fs/ext4 | |
| parent | 5dec43e3d688390256df3343bb444e7ed0022f44 (diff) | |
| download | lwn-fd80f53550720f200ca0469e9419c750f895ab50.tar.gz lwn-fd80f53550720f200ca0469e9419c750f895ab50.zip | |
ext4: fix race in ext4_mb_add_n_trim()
commit f1167009711032b0d747ec89a632a626c901a1ad upstream.
In ext4_mb_add_n_trim(), lg_prealloc_lock should be taken when
changing the lg_prealloc_list.
Signed-off-by: Niu Yawei <yawei.niu@intel.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/mballoc.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index b6adf68a5c02..31bbdb52b899 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4111,7 +4111,7 @@ static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac) /* The max size of hash table is PREALLOC_TB_SIZE */ order = PREALLOC_TB_SIZE - 1; /* Add the prealloc space to lg */ - rcu_read_lock(); + spin_lock(&lg->lg_prealloc_lock); list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order], pa_inode_list) { spin_lock(&tmp_pa->pa_lock); @@ -4135,12 +4135,12 @@ static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac) if (!added) list_add_tail_rcu(&pa->pa_inode_list, &lg->lg_prealloc_list[order]); - rcu_read_unlock(); + spin_unlock(&lg->lg_prealloc_lock); /* Now trim the list to be not more than 8 elements */ if (lg_prealloc_count > 8) { ext4_mb_discard_lg_preallocations(sb, lg, - order, lg_prealloc_count); + order, lg_prealloc_count); return; } return ; |