From 5c989a0ee06eb77a44baffd1779a5dbb9a7e873f Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Sun, 10 Dec 2017 18:03:54 -0800 Subject: xfs: remove dest file's post-eof preallocations before reflinking If we try to reflink into a file with post-eof preallocations at an offset well past the preallocations, we increase i_size as one would expect. However, those allocations do not have page cache backing them, so they won't get cleaned out on their own. This leads to asserts in the collapse/insert range code and xfs_destroy_inode when they encounter delalloc extents they weren't expecting to find. Since there are plenty of other places where we dump those post-eof blocks, do the same to the reflink destination file before we start remapping extents. This was found by adding clonerange support to fsstress and running it in write-only mode. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_reflink.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'fs/xfs/xfs_reflink.c') diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index cf7c8f81bebb..e13f5ad57a03 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -1291,6 +1291,17 @@ xfs_reflink_remap_range( trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); + /* + * Clear out post-eof preallocations because we don't have page cache + * backing the delayed allocations and they'll never get freed on + * their own. + */ + if (xfs_can_free_eofblocks(dest, true)) { + ret = xfs_free_eofblocks(dest); + if (ret) + goto out_unlock; + } + /* Set flags and remap blocks. */ ret = xfs_reflink_set_inode_flag(src, dest); if (ret) -- cgit v1.2.3 From 73353f486c9b5b2407ec32be1004174dbbaf6c18 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Sun, 10 Dec 2017 18:03:55 -0800 Subject: xfs: relax is_reflink_inode assert in xfs_reflink_find_cow_mapping We don't hold the ilock through the entire sequence of xfs_writepage_map -> xfs_map_cow -> xfs_reflink_find_cow_mapping. This means that we can race with another thread that is trying to clear the inode reflink flag, with the result that the flag is set for the xfs_map_cow check but cleared before we get to the assert in find_cow_mapping. When this happens, we blow the assert even though everything is fine. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_reflink.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'fs/xfs/xfs_reflink.c') diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index e13f5ad57a03..99c5852f9fe7 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -490,8 +490,9 @@ xfs_reflink_find_cow_mapping( struct xfs_iext_cursor icur; ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED)); - ASSERT(xfs_is_reflink_inode(ip)); + if (!xfs_is_reflink_inode(ip)) + return false; offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &icur, &got)) return false; -- cgit v1.2.3 From 9d40fba8b2056773b9744a95df9ddd6cc33a4f83 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Sun, 10 Dec 2017 18:03:55 -0800 Subject: xfs: avoid infinite loop when cancelling CoW blocks after writeback failure When we're cancelling a cow range, we don't always delete each extent that we iterate, so we have to move icur backwards in the list to avoid an infinite loop. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_reflink.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/xfs/xfs_reflink.c') diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 99c5852f9fe7..6931b0c79cac 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -611,6 +611,9 @@ xfs_reflink_cancel_cow_blocks( /* Remove the mapping from the CoW fork. */ xfs_bmap_del_extent_cow(ip, &icur, &got, &del); + } else { + /* Didn't do anything, push cursor back. */ + xfs_iext_prev(ifp, &icur); } next_extent: if (!xfs_iext_get_extent(ifp, &icur, &got)) -- cgit v1.2.3 From a192de265b26c525672884630d5376c405e83b2a Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Sun, 10 Dec 2017 18:03:56 -0800 Subject: xfs: allow CoW remap transactions to use reserve blocks Since we as yet have no way of holding on to the indlen blocks that are reserved as part of CoW fork delalloc reservations, let the CoW remap transaction dip into the reserves so that we avoid failing writes. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_reflink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/xfs/xfs_reflink.c') diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 6931b0c79cac..e49e6db415f7 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -729,7 +729,7 @@ xfs_reflink_end_cow( (unsigned int)(end_fsb - offset_fsb), XFS_DATA_FORK); error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, - resblks, 0, 0, &tp); + resblks, 0, XFS_TRANS_RESERVE, &tp); if (error) goto out; -- cgit v1.2.3 From 86d692bfad1b0097fa866f5fcfa5f5adf4cd82e8 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 14 Dec 2017 15:46:06 -0800 Subject: xfs: set cowblocks tag for direct cow writes too If a user performs a direct CoW write, we end up loading the CoW fork with preallocated extents. Therefore, we must set the cowblocks tag so that they can be cleared out if we run low on space. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_reflink.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/xfs/xfs_reflink.c') diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index e49e6db415f7..47aea2e82c26 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -454,6 +454,8 @@ retry: if (error) goto out_bmap_cancel; + xfs_inode_set_cowblocks_tag(ip); + /* Finish up. */ error = xfs_defer_finish(&tp, &dfops); if (error) -- cgit v1.2.3