diff mbox series

[v4,20/27] btrfs: wait existing extents before truncating

Message ID 20190823101036.796932-21-naohiro.aota@wdc.com (mailing list archive)
State New, archived
Headers show
Series btrfs zoned block device support | expand

Commit Message

Naohiro Aota Aug. 23, 2019, 10:10 a.m. UTC 
When truncating a file, file buffers which have already been allocated but
not yet written may be truncated.  Truncating these buffers could cause
breakage of a sequential write pattern in a block group if the truncated
blocks are for example followed by blocks allocated to another file. To
avoid this problem, always wait for write out of all unwritten buffers
before proceeding with the truncate execution.

Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
---
 fs/btrfs/inode.c | 10 ++++++++++
 1 file changed, 10 insertions(+)
diff mbox series

Patch

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index d7be97c6a069..95f4ce8ac8d0 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5236,6 +5236,16 @@  static int btrfs_setsize(struct inode *inode, struct iattr *attr)
 		btrfs_end_write_no_snapshotting(root);
 		btrfs_end_transaction(trans);
 	} else {
+		struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+
+		if (btrfs_fs_incompat(fs_info, HMZONED)) {
+			ret = btrfs_wait_ordered_range(
+				inode,
+				ALIGN(newsize, fs_info->sectorsize),
+				(u64)-1);
+			if (ret)
+				return ret;
+		}
 
 		/*
 		 * We're truncating a file that used to have good data down to