From 01c2e13dcae9757ea987af8933f9fcc6e33f2d7c Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 18 Jan 2018 14:07:53 -0800 Subject: xfs: only grab shared inode locks for source file during reflink Reflink and dedupe operations remap blocks from a source file into a destination file. The destination file needs exclusive locks on all levels because we're updating its block map, but the source file isn't undergoing any block map changes so we can use a shared lock. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_reflink.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) (limited to 'fs/xfs/xfs_reflink.c') diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index bcc58c24287c..85a119e1463b 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -1202,13 +1202,16 @@ xfs_reflink_remap_blocks( /* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */ while (len) { + uint lock_mode; + trace_xfs_reflink_remap_blocks_loop(src, srcoff, len, dest, destoff); + /* Read extent from the source file */ nimaps = 1; - xfs_ilock(src, XFS_ILOCK_EXCL); + lock_mode = xfs_ilock_data_map_shared(src); error = xfs_bmapi_read(src, srcoff, len, &imap, &nimaps, 0); - xfs_iunlock(src, XFS_ILOCK_EXCL); + xfs_iunlock(src, lock_mode); if (error) goto err; ASSERT(nimaps == 1); @@ -1260,7 +1263,7 @@ xfs_iolock_two_inodes_and_break_layout( retry: if (src < dest) { - inode_lock(src); + inode_lock_shared(src); inode_lock_nested(dest, I_MUTEX_NONDIR2); } else { /* src >= dest */ @@ -1271,7 +1274,7 @@ retry: if (error == -EWOULDBLOCK) { inode_unlock(dest); if (src < dest) - inode_unlock(src); + inode_unlock_shared(src); error = break_layout(dest, true); if (error) return error; @@ -1280,11 +1283,11 @@ retry: if (error) { inode_unlock(dest); if (src < dest) - inode_unlock(src); + inode_unlock_shared(src); return error; } if (src > dest) - inode_lock_nested(src, I_MUTEX_NONDIR2); + inode_lock_shared_nested(src, I_MUTEX_NONDIR2); return 0; } @@ -1324,7 +1327,7 @@ xfs_reflink_remap_range( if (same_inode) xfs_ilock(src, XFS_MMAPLOCK_EXCL); else - xfs_lock_two_inodes(src, XFS_MMAPLOCK_EXCL, dest, + xfs_lock_two_inodes(src, XFS_MMAPLOCK_SHARED, dest, XFS_MMAPLOCK_EXCL); /* Check file eligibility and prepare for block sharing. */ @@ -1393,10 +1396,12 @@ xfs_reflink_remap_range( is_dedupe); out_unlock: - xfs_iunlock(src, XFS_MMAPLOCK_EXCL); + xfs_iunlock(dest, XFS_MMAPLOCK_EXCL); + if (!same_inode) + xfs_iunlock(src, XFS_MMAPLOCK_SHARED); + inode_unlock(inode_out); if (!same_inode) - xfs_iunlock(dest, XFS_MMAPLOCK_EXCL); - unlock_two_nondirectories(inode_in, inode_out); + inode_unlock_shared(inode_in); if (ret) trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_); return ret; -- cgit