Enable multigrain timestamps, which should ensure that there is an
apparent change to the timestamp whenever it has been written after
being actively observed via getattr.
Beyond enabling the FS_MGTIME flag, this patch eliminates
update_time_for_write, which goes to great pains to avoid in-memory
stores. Just have it overwrite the timestamps unconditionally.
Note that this also drops the IS_I_VERSION check and unconditionally
bumps the change attribute, since SB_I_VERSION is always set on btrfs.
Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
Tested-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> # documentation bits
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/btrfs/file.c | 25 ++++---------------------
fs/btrfs/super.c | 3 ++-
2 files changed, 6 insertions(+), 22 deletions(-)
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 2aeb8116549c..1656ad7498b8 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1120,26 +1120,6 @@ void btrfs_check_nocow_unlock(struct btrfs_inode *inode)
btrfs_drew_write_unlock(&inode->root->snapshot_lock);
}
-static void update_time_for_write(struct inode *inode)
-{
- struct timespec64 now, ts;
-
- if (IS_NOCMTIME(inode))
- return;
-
- now = current_time(inode);
- ts = inode_get_mtime(inode);
- if (!timespec64_equal(&ts, &now))
- inode_set_mtime_to_ts(inode, now);
-
- ts = inode_get_ctime(inode);
- if (!timespec64_equal(&ts, &now))
- inode_set_ctime_to_ts(inode, now);
-
- if (IS_I_VERSION(inode))
- inode_inc_iversion(inode);
-}
-
int btrfs_write_check(struct kiocb *iocb, struct iov_iter *from, size_t count)
{
struct file *file = iocb->ki_filp;
@@ -1170,7 +1150,10 @@ int btrfs_write_check(struct kiocb *iocb, struct iov_iter *from, size_t count)
* need to start yet another transaction to update the inode as we will
* update the inode when we finish writing whatever data we write.
*/
- update_time_for_write(inode);
+ if (!IS_NOCMTIME(inode)) {
+ inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
+ inode_inc_iversion(inode);
+ }
start_pos = round_down(pos, fs_info->sectorsize);
oldsize = i_size_read(inode);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 98fa0f382480..d423acfe11d0 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2198,7 +2198,8 @@ static struct file_system_type btrfs_fs_type = {
.init_fs_context = btrfs_init_fs_context,
.parameters = btrfs_fs_parameters,
.kill_sb = btrfs_kill_super,
- .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_ALLOW_IDMAP,
+ .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA |
+ FS_ALLOW_IDMAP | FS_MGTIME,
};
MODULE_ALIAS_FS("btrfs");
--
2.46.2
