Btrfs: don't update atime on RO subvolumes (2bc55652) · Commits · 戴 / test

Before the update_time inode operation was indroduced, it was not possible to prevent updates of atime on RO subvolumes. VFS was only able to check for RO on the mount, but did not know anything about btrfs subvolumes. btrfs_update_time does now check if the root is RO and skip updating of times. Signed-off-by:

Alexander Block <ablock84@googlemail.com>

fs/btrfs/inode.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -4518,6 +4518,11 @@ int btrfs_dirty_inode(struct inode *inode)
		static int btrfs_update_time(struct inode inode, struct timespec now,
		int flags)
		{
		struct btrfs_root *root = BTRFS_I(inode)->root;

		if (btrfs_root_readonly(root))
		return -EROFS;

		if (flags & S_VERSION)
		inode_inc_iversion(inode);
		if (flags & S_CTIME)

fs/inode.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1551,6 +1551,8 @@ void touch_atime(struct path *path)
		* Btrfs), but since we touch atime while walking down the path we
		* really don't care if we failed to update the atime of the file,
		* so just ignore the return value.
		* We may also fail on filesystems that have the ability to make parts
		* of the fs read only, e.g. subvolumes in Btrfs.
		*/
		update_time(inode, &now, S_ATIME);
		mnt_drop_write(mnt);

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