| Message ID | 20210923130814.140814-10-cgxu519@mykernel.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | implement containerized syncfs for overlayfs | expand |
On Thu, Sep 23, 2021 at 4:08 PM Chengguang Xu <cgxu519@mykernel.net> wrote: > > Overlayfs needs to call upper layer's ->sync_fs > and __sync_blockdev() to sync metadata during syncfs(2). > > Currently, __sync_blockdev() does not export to module > so introduce new helper sync_fs_and_blockdev() to wrap > those operations. Heads up: looks like __sync_blockdev() will be gone soon, but you will have other exported symbols that overlayfs can use https://lore.kernel.org/linux-fsdevel/20211019062530.2174626-1-hch@lst.de/T/ Thanks, Amir.
---- 在 星期二, 2021-10-19 15:15:28 Amir Goldstein <amir73il@gmail.com> 撰写 ---- > On Thu, Sep 23, 2021 at 4:08 PM Chengguang Xu <cgxu519@mykernel.net> wrote: > > > > Overlayfs needs to call upper layer's ->sync_fs > > and __sync_blockdev() to sync metadata during syncfs(2). > > > > Currently, __sync_blockdev() does not export to module > > so introduce new helper sync_fs_and_blockdev() to wrap > > those operations. > > Heads up: looks like __sync_blockdev() will be gone soon, > but you will have other exported symbols that overlayfs can use > > https://lore.kernel.org/linux-fsdevel/20211019062530.2174626-1-hch@lst.de/T/ > Hi Amir, Thanks for the information. Chengguang,
diff --git a/fs/sync.c b/fs/sync.c index 1373a610dc78..36c755e6568a 100644 --- a/fs/sync.c +++ b/fs/sync.c @@ -21,6 +21,15 @@ #define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \ SYNC_FILE_RANGE_WAIT_AFTER) + +int sync_fs_and_blockdev(struct super_block *sb, int wait) +{ + if (sb->s_op->sync_fs) + sb->s_op->sync_fs(sb, wait); + return __sync_blockdev(sb->s_bdev, wait); +} +EXPORT_SYMBOL(sync_fs_and_blockdev); + /* * Do the filesystem syncing work. For simple filesystems * writeback_inodes_sb(sb) just dirties buffers with inodes so we have to @@ -34,10 +43,7 @@ static int __sync_filesystem(struct super_block *sb, int wait) sync_inodes_sb(sb); else writeback_inodes_sb(sb, WB_REASON_SYNC); - - if (sb->s_op->sync_fs) - sb->s_op->sync_fs(sb, wait); - return __sync_blockdev(sb->s_bdev, wait); + return sync_fs_and_blockdev(sb, wait); } /* diff --git a/include/linux/fs.h b/include/linux/fs.h index e7a633353fd2..e5ebf126281c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2777,6 +2777,7 @@ static inline bool sb_is_blkdev_sb(struct super_block *sb) void emergency_thaw_all(void); extern int sync_filesystem(struct super_block *); +extern int sync_fs_and_blockdev(struct super_block *sb, int wait); extern const struct file_operations def_blk_fops; extern const struct file_operations def_chr_fops;
Overlayfs needs to call upper layer's ->sync_fs and __sync_blockdev() to sync metadata during syncfs(2). Currently, __sync_blockdev() does not export to module so introduce new helper sync_fs_and_blockdev() to wrap those operations. Signed-off-by: Chengguang Xu <cgxu519@mykernel.net> --- fs/sync.c | 14 ++++++++++---- include/linux/fs.h | 1 + 2 files changed, 11 insertions(+), 4 deletions(-)