ocfs2: take ip_alloc_sem in ocfs2_dio_get_block & ocfs2_dio_end_io_write

Take ip_alloc_sem to prevent concurrent access to extent tree, which may
cause the extent tree in an unstable state.

Signed-off-by: Ryan Ding <ryan.ding@oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 843475793504299aea8348bf2312eede339e4846..0f3816325808f34aa61bdc58efff2516cc35cd36 100644 (file)
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -2151,6 +2151,7 @@ static int ocfs2_dio_get_block(struct inode *inode, sector_t iblock,
                               struct buffer_head *bh_result, int create)
 {
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+       struct ocfs2_inode_info *oi = OCFS2_I(inode);
        struct ocfs2_write_ctxt *wc;
        struct ocfs2_write_cluster_desc *desc = NULL;
        struct ocfs2_dio_write_ctxt *dwc = NULL;
@@ -2166,9 +2167,12 @@ static int ocfs2_dio_get_block(struct inode *inode, sector_t iblock,
        mlog(0, "get block of %lu at %llu:%u req %u\n",
                        inode->i_ino, pos, len, total_len);
 
+       down_read(&oi->ip_alloc_sem);
        /* This is the fast path for re-write. */
        ret = ocfs2_get_block(inode, iblock, bh_result, create);
 
+       up_read(&oi->ip_alloc_sem);
+
        if (buffer_mapped(bh_result) &&
            !buffer_new(bh_result) &&
            ret == 0)
@@ -2206,6 +2210,8 @@ static int ocfs2_dio_get_block(struct inode *inode, sector_t iblock,
                goto out;
        }
 
+       down_write(&oi->ip_alloc_sem);
+
        if (first_get_block) {
                if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
                        ret = ocfs2_zero_tail(inode, di_bh, pos);
@@ -2259,6 +2265,7 @@ static int ocfs2_dio_get_block(struct inode *inode, sector_t iblock,
        BUG_ON(ret != len);
        ret = 0;
 unlock:
+       up_write(&oi->ip_alloc_sem);
        ocfs2_inode_unlock(inode, 1);
        brelse(di_bh);
 out:
@@ -2275,6 +2282,7 @@ static void ocfs2_dio_end_io_write(struct inode *inode,
        struct ocfs2_cached_dealloc_ctxt dealloc;
        struct ocfs2_extent_tree et;
        struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+       struct ocfs2_inode_info *oi = OCFS2_I(inode);
        struct ocfs2_unwritten_extent *ue = NULL;
        struct buffer_head *di_bh = NULL;
        struct ocfs2_dinode *di;
@@ -2293,12 +2301,6 @@ static void ocfs2_dio_end_io_write(struct inode *inode,
            !dwc->dw_orphaned)
                goto out;
 
-       ret = ocfs2_inode_lock(inode, &di_bh, 1);
-       if (ret < 0) {
-               mlog_errno(ret);
-               goto out;
-       }
-
        /* ocfs2_file_write_iter will get i_mutex, so we need not lock if we
         * are in that context. */
        if (dwc->dw_writer_pid != task_pid_nr(current)) {
@@ -2306,6 +2308,14 @@ static void ocfs2_dio_end_io_write(struct inode *inode,
                locked = 1;
        }
 
+       ret = ocfs2_inode_lock(inode, &di_bh, 1);
+       if (ret < 0) {
+               mlog_errno(ret);
+               goto out;
+       }
+
+       down_write(&oi->ip_alloc_sem);
+
        /* Delete orphan before acquire i_mutex. */
        if (dwc->dw_orphaned) {
                BUG_ON(dwc->dw_writer_pid != task_pid_nr(current));
@@ -2359,6 +2369,7 @@ static void ocfs2_dio_end_io_write(struct inode *inode,
 commit:
        ocfs2_commit_trans(osb, handle);
 unlock:
+       up_write(&oi->ip_alloc_sem);
        ocfs2_inode_unlock(inode, 1);
        brelse(di_bh);
 out: