From 723cac48473358939759885a18e8df113ea96138 Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 23 Feb 2015 21:47:29 +1100 Subject: xfs: lock out page faults from extent swap operations Extent swap operations are another extent manipulation operation that we need to ensure does not race against mmap page faults. The current code returns if the file is mapped prior to the swap being done, but it could potentially race against new page faults while the swap is in progress. Hence we should use the XFS_MMAPLOCK_EXCL for this operation, too. While there, fix the error path handling that can result in double unlocks of the inodes when cancelling the swapext transaction. Signed-off-by: Dave Chinner Reviewed-by: Brian Foster Signed-off-by: Dave Chinner --- fs/xfs/xfs_bmap_util.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) (limited to 'fs/xfs/xfs_bmap_util.c') diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index 22a5dcb70b32..7efa23e72a90 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -1599,13 +1599,6 @@ xfs_swap_extent_flush( /* Verify O_DIRECT for ftmp */ if (VFS_I(ip)->i_mapping->nrpages) return -EINVAL; - - /* - * Don't try to swap extents on mmap()d files because we can't lock - * out races against page faults safely. - */ - if (mapping_mapped(VFS_I(ip)->i_mapping)) - return -EBUSY; return 0; } @@ -1633,13 +1626,14 @@ xfs_swap_extents( } /* - * Lock up the inodes against other IO and truncate to begin with. - * Then we can ensure the inodes are flushed and have no page cache - * safely. Once we have done this we can take the ilocks and do the rest - * of the checks. + * Lock the inodes against other IO, page faults and truncate to + * begin with. Then we can ensure the inodes are flushed and have no + * page cache safely. Once we have done this we can take the ilocks and + * do the rest of the checks. */ - lock_flags = XFS_IOLOCK_EXCL; + lock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL; xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL); + xfs_lock_two_inodes(ip, tip, XFS_MMAPLOCK_EXCL); /* Verify that both files have the same format */ if ((ip->i_d.di_mode & S_IFMT) != (tip->i_d.di_mode & S_IFMT)) { @@ -1666,8 +1660,16 @@ xfs_swap_extents( xfs_trans_cancel(tp, 0); goto out_unlock; } + + /* + * Lock and join the inodes to the tansaction so that transaction commit + * or cancel will unlock the inodes from this point onwards. + */ xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL); lock_flags |= XFS_ILOCK_EXCL; + xfs_trans_ijoin(tp, ip, lock_flags); + xfs_trans_ijoin(tp, tip, lock_flags); + /* Verify all data are being swapped */ if (sxp->sx_offset != 0 || @@ -1720,9 +1722,6 @@ xfs_swap_extents( goto out_trans_cancel; } - xfs_trans_ijoin(tp, ip, lock_flags); - xfs_trans_ijoin(tp, tip, lock_flags); - /* * Before we've swapped the forks, lets set the owners of the forks * appropriately. We have to do this as we are demand paging the btree @@ -1856,5 +1855,5 @@ out_unlock: out_trans_cancel: xfs_trans_cancel(tp, 0); - goto out_unlock; + goto out; } -- cgit v1.2.3 From a904b1ca5751faf5ece8600e18cd3b674afcca1b Mon Sep 17 00:00:00 2001 From: Namjae Jeon Date: Wed, 25 Mar 2015 15:08:56 +1100 Subject: xfs: Add support FALLOC_FL_INSERT_RANGE for fallocate This patch implements fallocate's FALLOC_FL_INSERT_RANGE for XFS. 1) Make sure that both offset and len are block size aligned. 2) Update the i_size of inode by len bytes. 3) Compute the file's logical block number against offset. If the computed block number is not the starting block of the extent, split the extent such that the block number is the starting block of the extent. 4) Shift all the extents which are lying bewteen [offset, last allocated extent] towards right by len bytes. This step will make a hole of len bytes at offset. Signed-off-by: Namjae Jeon Signed-off-by: Ashish Sangwan Reviewed-by: Brian Foster Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/xfs/xfs_bmap_util.c | 131 ++++++++++++++++++++++++++++++++++++------------- 1 file changed, 96 insertions(+), 35 deletions(-) (limited to 'fs/xfs/xfs_bmap_util.c') diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index 22a5dcb70b32..fe1f11b96d0d 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -1376,22 +1376,19 @@ out: } /* - * xfs_collapse_file_space() - * This routine frees disk space and shift extent for the given file. - * The first thing we do is to free data blocks in the specified range - * by calling xfs_free_file_space(). It would also sync dirty data - * and invalidate page cache over the region on which collapse range - * is working. And Shift extent records to the left to cover a hole. - * RETURNS: - * 0 on success - * errno on error - * + * @next_fsb will keep track of the extent currently undergoing shift. + * @stop_fsb will keep track of the extent at which we have to stop. + * If we are shifting left, we will start with block (offset + len) and + * shift each extent till last extent. + * If we are shifting right, we will start with last extent inside file space + * and continue until we reach the block corresponding to offset. */ int -xfs_collapse_file_space( - struct xfs_inode *ip, - xfs_off_t offset, - xfs_off_t len) +xfs_shift_file_space( + struct xfs_inode *ip, + xfs_off_t offset, + xfs_off_t len, + enum shift_direction direction) { int done = 0; struct xfs_mount *mp = ip->i_mount; @@ -1400,21 +1397,26 @@ xfs_collapse_file_space( struct xfs_bmap_free free_list; xfs_fsblock_t first_block; int committed; - xfs_fileoff_t start_fsb; + xfs_fileoff_t stop_fsb; xfs_fileoff_t next_fsb; xfs_fileoff_t shift_fsb; - ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL)); + ASSERT(direction == SHIFT_LEFT || direction == SHIFT_RIGHT); - trace_xfs_collapse_file_space(ip); + if (direction == SHIFT_LEFT) { + next_fsb = XFS_B_TO_FSB(mp, offset + len); + stop_fsb = XFS_B_TO_FSB(mp, VFS_I(ip)->i_size); + } else { + /* + * If right shift, delegate the work of initialization of + * next_fsb to xfs_bmap_shift_extent as it has ilock held. + */ + next_fsb = NULLFSBLOCK; + stop_fsb = XFS_B_TO_FSB(mp, offset); + } - next_fsb = XFS_B_TO_FSB(mp, offset + len); shift_fsb = XFS_B_TO_FSB(mp, len); - error = xfs_free_file_space(ip, offset, len); - if (error) - return error; - /* * Trim eofblocks to avoid shifting uninitialized post-eof preallocation * into the accessible region of the file. @@ -1427,20 +1429,28 @@ xfs_collapse_file_space( /* * Writeback and invalidate cache for the remainder of the file as we're - * about to shift down every extent from the collapse range to EOF. The - * free of the collapse range above might have already done some of - * this, but we shouldn't rely on it to do anything outside of the range - * that was freed. + * about to shift down every extent from offset to EOF. */ error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping, - offset + len, -1); + offset, -1); if (error) return error; error = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping, - (offset + len) >> PAGE_CACHE_SHIFT, -1); + offset >> PAGE_CACHE_SHIFT, -1); if (error) return error; + /* + * The extent shiting code works on extent granularity. So, if + * stop_fsb is not the starting block of extent, we need to split + * the extent at stop_fsb. + */ + if (direction == SHIFT_RIGHT) { + error = xfs_bmap_split_extent(ip, stop_fsb); + if (error) + return error; + } + while (!error && !done) { tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT); /* @@ -1464,7 +1474,7 @@ xfs_collapse_file_space( if (error) goto out; - xfs_trans_ijoin(tp, ip, 0); + xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL); xfs_bmap_init(&free_list, &first_block); @@ -1472,10 +1482,9 @@ xfs_collapse_file_space( * We are using the write transaction in which max 2 bmbt * updates are allowed */ - start_fsb = next_fsb; - error = xfs_bmap_shift_extents(tp, ip, start_fsb, shift_fsb, - &done, &next_fsb, &first_block, &free_list, - XFS_BMAP_MAX_SHIFT_EXTENTS); + error = xfs_bmap_shift_extents(tp, ip, &next_fsb, shift_fsb, + &done, stop_fsb, &first_block, &free_list, + direction, XFS_BMAP_MAX_SHIFT_EXTENTS); if (error) goto out; @@ -1484,17 +1493,69 @@ xfs_collapse_file_space( goto out; error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); - xfs_iunlock(ip, XFS_ILOCK_EXCL); } return error; out: xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT); - xfs_iunlock(ip, XFS_ILOCK_EXCL); return error; } +/* + * xfs_collapse_file_space() + * This routine frees disk space and shift extent for the given file. + * The first thing we do is to free data blocks in the specified range + * by calling xfs_free_file_space(). It would also sync dirty data + * and invalidate page cache over the region on which collapse range + * is working. And Shift extent records to the left to cover a hole. + * RETURNS: + * 0 on success + * errno on error + * + */ +int +xfs_collapse_file_space( + struct xfs_inode *ip, + xfs_off_t offset, + xfs_off_t len) +{ + int error; + + ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL)); + trace_xfs_collapse_file_space(ip); + + error = xfs_free_file_space(ip, offset, len); + if (error) + return error; + + return xfs_shift_file_space(ip, offset, len, SHIFT_LEFT); +} + +/* + * xfs_insert_file_space() + * This routine create hole space by shifting extents for the given file. + * The first thing we do is to sync dirty data and invalidate page cache + * over the region on which insert range is working. And split an extent + * to two extents at given offset by calling xfs_bmap_split_extent. + * And shift all extent records which are laying between [offset, + * last allocated extent] to the right to reserve hole range. + * RETURNS: + * 0 on success + * errno on error + */ +int +xfs_insert_file_space( + struct xfs_inode *ip, + loff_t offset, + loff_t len) +{ + ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL)); + trace_xfs_insert_file_space(ip); + + return xfs_shift_file_space(ip, offset, len, SHIFT_RIGHT); +} + /* * We need to check that the format of the data fork in the temporary inode is * valid for the target inode before doing the swap. This is not a problem with -- cgit v1.2.3 From 72c1a73993cfa3572e45e1a878ff7acf31d14fc8 Mon Sep 17 00:00:00 2001 From: kbuild test robot Date: Mon, 13 Apr 2015 11:25:04 +1000 Subject: xfs: xfs_shift_file_space can be static Signed-off-by: Fengguang Wu Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/xfs/xfs_bmap_util.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/xfs/xfs_bmap_util.c') diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index fe1f11b96d0d..e86757358d5b 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -1383,7 +1383,7 @@ out: * If we are shifting right, we will start with last extent inside file space * and continue until we reach the block corresponding to offset. */ -int +static int xfs_shift_file_space( struct xfs_inode *ip, xfs_off_t offset, -- cgit v1.2.3