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authorYunlong Song <yunlong.song@huawei.com>2018-09-18 15:39:53 +0300
committerJaegeuk Kim <jaegeuk@kernel.org>2018-11-27 02:53:54 +0300
commit9bf1a3f73927492c8be127b642197125e9d52be8 (patch)
tree853a4fe4306fef8a7a68dd7d2f5f9be2ac533be5
parent6f8b52ba442ce1372a58df4e85f169686ef52a0d (diff)
downloadlinux-9bf1a3f73927492c8be127b642197125e9d52be8.tar.xz
f2fs: avoid GC causing encrypted file corrupted
The encrypted file may be corrupted by GC in following case: Time 1: | segment 1 blkaddr = A | GC -> | segment 2 blkaddr = B | Encrypted block 1 is moved from blkaddr A of segment 1 to blkaddr B of segment 2, Time 2: | segment 1 blkaddr = B | GC -> | segment 3 blkaddr = C | Before page 1 is written back and if segment 2 become a victim, then page 1 is moved from blkaddr B of segment 2 to blkaddr Cof segment 3, during the GC process of Time 2, f2fs should wait for page 1 written back before reading it, or move_data_block will read a garbage block from blkaddr B since page is not written back to blkaddr B yet. Commit 6aa58d8a ("f2fs: readahead encrypted block during GC") introduce ra_data_block to read encrypted block, but it forgets to add f2fs_wait_on_page_writeback to avoid racing between GC and flush. Signed-off-by: Yunlong Song <yunlong.song@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
-rw-r--r--fs/f2fs/gc.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index a07241fb8537..c96e7c6354ef 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -658,6 +658,14 @@ got_it:
fio.page = page;
fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
+ /*
+ * don't cache encrypted data into meta inode until previous dirty
+ * data were writebacked to avoid racing between GC and flush.
+ */
+ f2fs_wait_on_page_writeback(page, DATA, true);
+
+ f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
+
fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
dn.data_blkaddr,
FGP_LOCK | FGP_CREAT, GFP_NOFS);
@@ -745,6 +753,8 @@ static int move_data_block(struct inode *inode, block_t bidx,
*/
f2fs_wait_on_page_writeback(page, DATA, true);
+ f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
+
err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
if (err)
goto put_out;