6.1-stable review patch. If anyone has any objections, please let me know.
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From: Christoph Hellwig hch@lst.de
[ Upstream commit 35dc55b9e80cb9ec4bcb969302000b002b2ed850 ]
If xfs_bmapi_write finds a delalloc extent at the requested range, it tries to convert the entire delalloc extent to a real allocation.
But if the allocator cannot find a single free extent large enough to cover the start block of the requested range, xfs_bmapi_write will return 0 but leave *nimaps set to 0.
In that case we simply need to keep looping with the same startoffset_fsb so that one of the following allocations will eventually reach the requested range.
Note that this could affect any caller of xfs_bmapi_write that covers an existing delayed allocation. As far as I can tell we do not have any other such caller, though - the regular writeback path uses xfs_bmapi_convert_delalloc to convert delayed allocations to real ones, and direct I/O invalidates the page cache first.
Signed-off-by: Christoph Hellwig hch@lst.de Reviewed-by: "Darrick J. Wong" djwong@kernel.org Signed-off-by: Chandan Babu R chandanbabu@kernel.org Signed-off-by: Leah Rumancik leah.rumancik@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/xfs/xfs_bmap_util.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-)
--- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -780,12 +780,10 @@ xfs_alloc_file_space( { xfs_mount_t *mp = ip->i_mount; xfs_off_t count; - xfs_filblks_t allocated_fsb; xfs_filblks_t allocatesize_fsb; xfs_extlen_t extsz, temp; xfs_fileoff_t startoffset_fsb; xfs_fileoff_t endoffset_fsb; - int nimaps; int rt; xfs_trans_t *tp; xfs_bmbt_irec_t imaps[1], *imapp; @@ -808,7 +806,6 @@ xfs_alloc_file_space(
count = len; imapp = &imaps[0]; - nimaps = 1; startoffset_fsb = XFS_B_TO_FSBT(mp, offset); endoffset_fsb = XFS_B_TO_FSB(mp, offset + count); allocatesize_fsb = endoffset_fsb - startoffset_fsb; @@ -819,6 +816,7 @@ xfs_alloc_file_space( while (allocatesize_fsb && !error) { xfs_fileoff_t s, e; unsigned int dblocks, rblocks, resblks; + int nimaps = 1;
/* * Determine space reservations for data/realtime. @@ -884,15 +882,19 @@ xfs_alloc_file_space( if (error) break;
- allocated_fsb = imapp->br_blockcount; - - if (nimaps == 0) { - error = -ENOSPC; - break; + /* + * If the allocator cannot find a single free extent large + * enough to cover the start block of the requested range, + * xfs_bmapi_write will return 0 but leave *nimaps set to 0. + * + * In that case we simply need to keep looping with the same + * startoffset_fsb so that one of the following allocations + * will eventually reach the requested range. + */ + if (nimaps) { + startoffset_fsb += imapp->br_blockcount; + allocatesize_fsb -= imapp->br_blockcount; } - - startoffset_fsb += allocated_fsb; - allocatesize_fsb -= allocated_fsb; }
return error;