From 85da94c6b4666582c38579ccdcd90a5d9b5697ef Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 10 Dec 2010 08:42:16 +0000 Subject: [PATCH] xfs: improve mapping type check in xfs_vm_writepage Currently we only refuse a "read-only" mapping for writing out unwritten and delayed buffers, and refuse any other for overwrites. Improve the checks to require delalloc mappings for delayed buffers, and unwritten extent mappings for unwritten extents. Signed-off-by: Christoph Hellwig Reviewed-by: Dave Chinner Signed-off-by: Alex Elder --- fs/xfs/linux-2.6/xfs_aops.c | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index 691f61223ed6..23a7668e07da 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -1082,17 +1082,17 @@ xfs_vm_writepage( if (buffer_unwritten(bh) || buffer_delay(bh)) { int new_ioend = 0; - /* - * Make sure we don't use a read-only iomap - */ - if (flags == BMAPI_READ) - imap_valid = 0; - if (buffer_unwritten(bh)) { - type = IO_UNWRITTEN; + if (type != IO_UNWRITTEN) { + type = IO_UNWRITTEN; + imap_valid = 0; + } flags = BMAPI_WRITE | BMAPI_IGNSTATE; } else if (buffer_delay(bh)) { - type = IO_DELAY; + if (type != IO_DELAY) { + type = IO_DELAY; + imap_valid = 0; + } flags = BMAPI_ALLOCATE; if (wbc->sync_mode == WB_SYNC_NONE) @@ -1128,8 +1128,11 @@ xfs_vm_writepage( * That means it must already have extents allocated * underneath it. Map the extent by reading it. */ - if (!imap_valid || flags != BMAPI_READ) { + if (flags != BMAPI_READ) { flags = BMAPI_READ; + imap_valid = 0; + } + if (!imap_valid) { size = xfs_probe_cluster(inode, page, bh, head); err = xfs_map_blocks(inode, offset, size, &imap, flags); -- 2.39.2