diff options
| author | alex chen <alex.chen@huawei.com> | 2017-11-15 17:31:44 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-15 18:21:01 -0800 |
| commit | 3e4c56d41eef5595035872a2ec5a483f42e8917f (patch) | |
| tree | f050c8e277b91c7bbc9e53986017c67eba1c6e3e | |
| parent | 28f5a8a7c033cbf3e32277f4cc9c6afd74f05300 (diff) | |
| download | linux-3e4c56d41eef5595035872a2ec5a483f42e8917f.tar.bz2 | |
ocfs2: ip_alloc_sem should be taken in ocfs2_get_block()
ip_alloc_sem should be taken in ocfs2_get_block() when reading file in
DIRECT mode to prevent concurrent access to extent tree with
ocfs2_dio_end_io_write(), which may cause BUGON in the following
situation:
read file 'A' end_io of writing file 'A'
vfs_read
__vfs_read
ocfs2_file_read_iter
generic_file_read_iter
ocfs2_direct_IO
__blockdev_direct_IO
do_blockdev_direct_IO
do_direct_IO
get_more_blocks
ocfs2_get_block
ocfs2_extent_map_get_blocks
ocfs2_get_clusters
ocfs2_get_clusters_nocache()
ocfs2_search_extent_list
return the index of record which
contains the v_cluster, that is
v_cluster > rec[i]->e_cpos.
ocfs2_dio_end_io
ocfs2_dio_end_io_write
down_write(&oi->ip_alloc_sem);
ocfs2_mark_extent_written
ocfs2_change_extent_flag
ocfs2_split_extent
...
--> modify the rec[i]->e_cpos, resulting
in v_cluster < rec[i]->e_cpos.
BUG_ON(v_cluster < le32_to_cpu(rec->e_cpos))
[alex.chen@huawei.com: v3]
Link: http://lkml.kernel.org/r/59EF3614.6050008@huawei.com
Link: http://lkml.kernel.org/r/59EF3614.6050008@huawei.com
Fixes: c15471f79506 ("ocfs2: fix sparse file & data ordering issue in direct io")
Signed-off-by: Alex Chen <alex.chen@huawei.com>
Reviewed-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Joseph Qi <jiangqi903@gmail.com>
Reviewed-by: Gang He <ghe@suse.com>
Acked-by: Changwei Ge <ge.changwei@h3c.com>
Cc: Mark Fasheh <mfasheh@versity.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/ocfs2/aops.c | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index 88a31e9340a0..d1516327b787 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -134,6 +134,19 @@ bail: return err; } +static int ocfs2_lock_get_block(struct inode *inode, sector_t iblock, + struct buffer_head *bh_result, int create) +{ + int ret = 0; + struct ocfs2_inode_info *oi = OCFS2_I(inode); + + down_read(&oi->ip_alloc_sem); + ret = ocfs2_get_block(inode, iblock, bh_result, create); + up_read(&oi->ip_alloc_sem); + + return ret; +} + int ocfs2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { @@ -2128,7 +2141,7 @@ static void ocfs2_dio_free_write_ctx(struct inode *inode, * called like this: dio->get_blocks(dio->inode, fs_startblk, * fs_count, map_bh, dio->rw == WRITE); */ -static int ocfs2_dio_get_block(struct inode *inode, sector_t iblock, +static int ocfs2_dio_wr_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); @@ -2154,12 +2167,9 @@ static int ocfs2_dio_get_block(struct inode *inode, sector_t iblock, * while file size will be changed. */ if (pos + total_len <= i_size_read(inode)) { - 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); + /* This is the fast path for re-write. */ + ret = ocfs2_lock_get_block(inode, iblock, bh_result, create); if (buffer_mapped(bh_result) && !buffer_new(bh_result) && ret == 0) @@ -2424,9 +2434,9 @@ static ssize_t ocfs2_direct_IO(struct kiocb *iocb, struct iov_iter *iter) return 0; if (iov_iter_rw(iter) == READ) - get_block = ocfs2_get_block; + get_block = ocfs2_lock_get_block; else - get_block = ocfs2_dio_get_block; + get_block = ocfs2_dio_wr_get_block; return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter, get_block, |