From 8ff2957d581582890693affc09920108a67cb05d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 10 Dec 2010 08:42:21 +0000 Subject: [PATCH] xfs: simplify xfs_map_blocks No need to lock the extent map exclusive when performing an overwrite, we know the extent map must already have been loaded by get_blocks. Apply the non-blocking inode semantics to all mapping types instead of just delayed allocations. Remove the handling of not yet allocated blocks for the IO_UNWRITTEN case - if an extent is marked as unwritten allocated in the buffer it must already have an extent on disk. Add asserts to verify all the assumptions above in debug builds. Signed-off-by: Christoph Hellwig Reviewed-by: Dave Chinner Signed-off-by: Alex Elder --- fs/xfs/linux-2.6/xfs_aops.c | 77 ++++++++++++------------------------- 1 file changed, 25 insertions(+), 52 deletions(-) diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index 365040f61d89..1252a8443429 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -313,81 +313,54 @@ xfs_map_blocks( struct xfs_mount *mp = ip->i_mount; xfs_fileoff_t offset_fsb, end_fsb; int error = 0; - int lockmode = 0; int bmapi_flags = XFS_BMAPI_ENTIRE; int nimaps = 1; if (XFS_FORCED_SHUTDOWN(mp)) return -XFS_ERROR(EIO); - switch (type) { - case IO_OVERWRITE: - lockmode = xfs_ilock_map_shared(ip); - break; - case IO_UNWRITTEN: - lockmode = XFS_ILOCK_EXCL; + if (type == IO_UNWRITTEN) bmapi_flags |= XFS_BMAPI_IGSTATE; - xfs_ilock(ip, lockmode); - break; - case IO_DELALLOC: - lockmode = XFS_ILOCK_SHARED; - - if (!xfs_ilock_nowait(ip, lockmode)) { - if (nonblocking) - return -XFS_ERROR(EAGAIN); - xfs_ilock(ip, lockmode); - } - break; + + if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) { + if (nonblocking) + return -XFS_ERROR(EAGAIN); + xfs_ilock(ip, XFS_ILOCK_SHARED); } + ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE || + (ip->i_df.if_flags & XFS_IFEXTENTS)); ASSERT(offset <= mp->m_maxioffset); + if (offset + count > mp->m_maxioffset) count = mp->m_maxioffset - offset; end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count); offset_fsb = XFS_B_TO_FSBT(mp, offset); - error = xfs_bmapi(NULL, ip, offset_fsb, end_fsb - offset_fsb, bmapi_flags, NULL, 0, imap, &nimaps, NULL); - if (error) - goto out; - - switch (type) { - case IO_UNWRITTEN: - /* If we found an extent, return it */ - if (nimaps && - (imap->br_startblock != HOLESTARTBLOCK) && - (imap->br_startblock != DELAYSTARTBLOCK)) { - trace_xfs_map_blocks_found(ip, offset, count, type, imap); - break; - } + xfs_iunlock(ip, XFS_ILOCK_SHARED); - error = xfs_iomap_write_delay(ip, offset, count, imap); - if (!error) - trace_xfs_map_blocks_alloc(ip, offset, count, type, imap); - break; - case IO_DELALLOC: - /* If we found an extent, return it */ - xfs_iunlock(ip, lockmode); - lockmode = 0; - - if (nimaps && !isnullstartblock(imap->br_startblock)) { - trace_xfs_map_blocks_found(ip, offset, count, type, imap); - break; - } + if (error) + return -XFS_ERROR(error); + if (type == IO_DELALLOC && + (!nimaps || isnullstartblock(imap->br_startblock))) { error = xfs_iomap_write_allocate(ip, offset, count, imap); if (!error) trace_xfs_map_blocks_alloc(ip, offset, count, type, imap); - break; - default: - if (nimaps) - trace_xfs_map_blocks_found(ip, offset, count, type, imap); + return -XFS_ERROR(error); } -out: - if (lockmode) - xfs_iunlock(ip, lockmode); - return -XFS_ERROR(error); +#ifdef DEBUG + if (type == IO_UNWRITTEN) { + ASSERT(nimaps); + ASSERT(imap->br_startblock != HOLESTARTBLOCK); + ASSERT(imap->br_startblock != DELAYSTARTBLOCK); + } +#endif + if (nimaps) + trace_xfs_map_blocks_found(ip, offset, count, type, imap); + return 0; } STATIC int -- 2.39.5