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| author | Jaegeuk Kim <jaegeuk@kernel.org> | 2017-07-25 04:46:29 +0200 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2017-07-29 02:49:01 +0200 |
| commit | 7a10f0177e117e9935ee9e5c595fcf3c57215de5 (patch) | |
| tree | 5b8f062a85ac3d175d0686323fc4c051ce484a17 /fs/f2fs/file.c | |
| parent | f2fs: give a try to do atomic write in -ENOMEM case (diff) | |
| download | linux-7a10f0177e117e9935ee9e5c595fcf3c57215de5.tar.xz linux-7a10f0177e117e9935ee9e5c595fcf3c57215de5.zip | |
f2fs: don't give partially written atomic data from process crash
This patch resolves the below scenario.
== Process 1 == == Process 2 ==
open(w) open(rw)
begin
write(new_#1)
process_crash
f_op->flush
locks_remove_posix
f_op>release
read (new_#1)
In order to avoid corrupted database caused by new_#1, we must do roll-back
at process_crash time. In order to check that, this patch keeps task which
triggers transaction begin, and does roll-back in f_op->flush before removing
file locks.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs/file.c')
| -rw-r--r-- | fs/f2fs/file.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 2706130c261b..75b3fda99e55 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1495,6 +1495,22 @@ static int f2fs_release_file(struct inode *inode, struct file *filp) return 0; } +static int f2fs_file_flush(struct file *file, fl_owner_t id) +{ + struct inode *inode = file_inode(file); + + /* + * If the process doing a transaction is crashed, we should do + * roll-back. Otherwise, other reader/write can see corrupted database + * until all the writers close its file. Since this should be done + * before dropping file lock, it needs to do in ->flush. + */ + if (f2fs_is_atomic_file(inode) && + F2FS_I(inode)->inmem_task == current) + drop_inmem_pages(inode); + return 0; +} + #define F2FS_REG_FLMASK (~(FS_DIRSYNC_FL | FS_TOPDIR_FL)) #define F2FS_OTHER_FLMASK (FS_NODUMP_FL | FS_NOATIME_FL) @@ -1614,6 +1630,7 @@ static int f2fs_ioc_start_atomic_write(struct file *filp) } inc_stat: + F2FS_I(inode)->inmem_task = current; stat_inc_atomic_write(inode); stat_update_max_atomic_write(inode); out: @@ -2506,6 +2523,7 @@ const struct file_operations f2fs_file_operations = { .open = f2fs_file_open, .release = f2fs_release_file, .mmap = f2fs_file_mmap, + .flush = f2fs_file_flush, .fsync = f2fs_sync_file, .fallocate = f2fs_fallocate, .unlocked_ioctl = f2fs_ioctl, |