ocfs2: Wrap access of directory allocations with ip_alloc_sem.
OCFS2_I(inode)->ip_alloc_sem is a read-write semaphore protecting
local concurrent access of ocfs2 inodes. However, ocfs2 directories were
not taking the semaphore while they accessed or modified the allocation
tree.
ocfs2_extend_dir() needs to take the semaphore in a write mode when it
adds to the allocation. All other directory users get there via
ocfs2_bread(), which takes the semaphore in read mode.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index 21a6050..58ec54b 100644
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -1106,8 +1106,10 @@
return NULL;
}
+ down_read(&OCFS2_I(inode)->ip_alloc_sem);
tmperr = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL,
NULL);
+ up_read(&OCFS2_I(inode)->ip_alloc_sem);
if (tmperr < 0) {
mlog_errno(tmperr);
goto fail;