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authorJaegeuk Kim <jaegeuk@kernel.org>2017-07-25 05:46:29 +0300
committerJaegeuk Kim <jaegeuk@kernel.org>2017-07-29 03:49:01 +0300
commit7a10f0177e117e9935ee9e5c595fcf3c57215de5 (patch)
tree5b8f062a85ac3d175d0686323fc4c051ce484a17 /fs/f2fs
parent640cc18982b1c2049ac3a7223444248aea7d51b4 (diff)
downloadlinux-7a10f0177e117e9935ee9e5c595fcf3c57215de5.tar.xz
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')
-rw-r--r--fs/f2fs/f2fs.h1
-rw-r--r--fs/f2fs/file.c18
2 files changed, 19 insertions, 0 deletions
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 70777a889e12..859ff4265c34 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -536,6 +536,7 @@ struct f2fs_inode_info {
struct list_head dirty_list; /* dirty list for dirs and files */
struct list_head gdirty_list; /* linked in global dirty list */
struct list_head inmem_pages; /* inmemory pages managed by f2fs */
+ struct task_struct *inmem_task; /* store inmemory task */
struct mutex inmem_lock; /* lock for inmemory pages */
struct extent_tree *extent_tree; /* cached extent_tree entry */
struct rw_semaphore dio_rwsem[2];/* avoid racing between dio and gc */
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,