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Commit 19fd2df5 authored by Liu Bo's avatar Liu Bo Committed by David Sterba
Browse files

Btrfs: fix btrfs_ordered_update_i_size to update disk_i_size properly 



btrfs_ordered_update_i_size can be called by truncate and endio, but
only endio takes ordered_extent which contains the completed IO.

while truncating down a file, if there are some in-flight IOs,
btrfs_ordered_update_i_size in endio will set disk_i_size to
@orig_offset that is zero.  If truncating-down fails somehow, we try to
recover in memory isize with this zero'd disk_i_size.

Fix it by only updating disk_i_size with @orig_offset when
btrfs_ordered_update_i_size is not called from endio while truncating
down and waiting for in-flight IOs completing their work before recover
in-memory size.

Besides fixing the above issue, add an assertion for last_size to double
check we truncate down to the desired size.

Signed-off-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent f85b7379

fs/btrfs/inode.c

+14 −0
Original line number Diff line number Diff line
@@ -4695,6 +4695,13 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, 


	btrfs_free_path(path);



	if (err == 0) {

		/* only inline file may have last_size != new_size */

		if (new_size >= fs_info->sectorsize ||

		    new_size > fs_info->max_inline)

			ASSERT(last_size == new_size);

	}



	if (be_nice && bytes_deleted > SZ_32M) {

		unsigned long updates = trans->delayed_ref_updates;

		if (updates) {
@@ -5080,6 +5087,13 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr) 
		if (ret && inode->i_nlink) {

			int err;



			/* To get a stable disk_i_size */

			err = btrfs_wait_ordered_range(inode, 0, (u64)-1);

			if (err) {

				btrfs_orphan_del(NULL, inode);

				return err;

			}



			/*

			 * failed to truncate, disk_i_size is only adjusted down

			 * as we remove extents, so it should represent the true

fs/btrfs/ordered-data.c

+12 −2
Original line number Diff line number Diff line
@@ -984,8 +984,18 @@ int btrfs_ordered_update_i_size(struct inode *inode, u64 offset, 
	}

	disk_i_size = BTRFS_I(inode)->disk_i_size;



	/* truncate file */

	if (disk_i_size > i_size) {

	/*

	 * truncate file.

	 * If ordered is not NULL, then this is called from endio and

	 * disk_i_size will be updated by either truncate itself or any

	 * in-flight IOs which are inside the disk_i_size.

	 *

	 * Because btrfs_setsize() may set i_size with disk_i_size if truncate

	 * fails somehow, we need to make sure we have a precise disk_i_size by

	 * updating it as usual.

	 *

	 */

	if (!ordered && disk_i_size > i_size) {

		BTRFS_I(inode)->disk_i_size = orig_offset;

		ret = 0;

		goto out;