diff options
| -rw-r--r-- | fs/xfs/libxfs/xfs_bmap.c | 16 | ||||
| -rw-r--r-- | fs/xfs/libxfs/xfs_bmap.h | 2 | ||||
| -rw-r--r-- | fs/xfs/xfs_iomap.c | 170 |
3 files changed, 64 insertions, 124 deletions
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index c629004d9a4c..f4a65330a2a9 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -4296,15 +4296,14 @@ xfs_bmapi_write( bma.datatype = 0; /* - * The reval flag means the caller wants to allocate the entire delalloc - * extent backing bno where bno may not necessarily match the startoff. - * Now that we've looked up the extent, reset the range to map based on - * the extent in the file. If we're in a hole, this may be an error so - * don't adjust anything. + * The delalloc flag means the caller wants to allocate the entire + * delalloc extent backing bno where bno may not necessarily match the + * startoff. Now that we've looked up the extent, reset the range to + * map based on the extent in the file. If we're in a hole, this may be + * an error so don't adjust anything. */ - if ((flags & XFS_BMAPI_REVALRANGE) && + if ((flags & XFS_BMAPI_DELALLOC) && !eof && bno >= bma.got.br_startoff) { - ASSERT(flags & XFS_BMAPI_DELALLOC); bno = bma.got.br_startoff; len = bma.got.br_blockcount; #ifdef DEBUG @@ -4495,10 +4494,9 @@ xfs_bmapi_convert_delalloc( flags |= XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC; /* - * The reval flag means to allocate the entire extent; pass a dummy + * The delalloc flag means to allocate the entire extent; pass a dummy * length of 1. */ - flags |= XFS_BMAPI_REVALRANGE; error = xfs_bmapi_write(tp, ip, offset_fsb, 1, flags, total, imap, &nimaps); if (!error && !nimaps) diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h index 75586d56f7a5..4dc7d1a02b35 100644 --- a/fs/xfs/libxfs/xfs_bmap.h +++ b/fs/xfs/libxfs/xfs_bmap.h @@ -107,8 +107,6 @@ struct xfs_extent_free_item /* Do not update the rmap btree. Used for reconstructing bmbt from rmapbt. */ #define XFS_BMAPI_NORMAP 0x2000 -#define XFS_BMAPI_REVALRANGE 0x4000 - #define XFS_BMAPI_FLAGS \ { XFS_BMAPI_ENTIRE, "ENTIRE" }, \ { XFS_BMAPI_METADATA, "METADATA" }, \ diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index ab69caa685b4..6af1d3ec0a9c 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -677,25 +677,19 @@ out_unlock: */ int xfs_iomap_write_allocate( - xfs_inode_t *ip, - int whichfork, - xfs_off_t offset, - xfs_bmbt_irec_t *imap, - unsigned int *seq) + struct xfs_inode *ip, + int whichfork, + xfs_off_t offset, + struct xfs_bmbt_irec *imap, + unsigned int *seq) { - xfs_mount_t *mp = ip->i_mount; - struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork); - xfs_fileoff_t offset_fsb, last_block; - xfs_fileoff_t end_fsb, map_start_fsb; - xfs_filblks_t count_fsb; - xfs_trans_t *tp; - int nimaps; - int error = 0; - int flags = XFS_BMAPI_DELALLOC; - int nres; - - if (whichfork == XFS_COW_FORK) - flags |= XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC; + struct xfs_mount *mp = ip->i_mount; + struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork); + xfs_fileoff_t offset_fsb; + xfs_fileoff_t map_start_fsb; + xfs_extlen_t map_count_fsb; + struct xfs_trans *tp; + int error = 0; /* * Make sure that the dquots are there. @@ -704,106 +698,60 @@ xfs_iomap_write_allocate( if (error) return error; + /* + * Store the file range the caller is interested in because it encodes + * state such as potential overlap with COW fork blocks. We must trim + * the allocated extent down to this range to maintain consistency with + * what the caller expects. Revalidation of the range itself is the + * responsibility of the caller. + */ offset_fsb = XFS_B_TO_FSBT(mp, offset); - count_fsb = imap->br_blockcount; map_start_fsb = imap->br_startoff; + map_count_fsb = imap->br_blockcount; - XFS_STATS_ADD(mp, xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb)); + XFS_STATS_ADD(mp, xs_xstrat_bytes, + XFS_FSB_TO_B(mp, imap->br_blockcount)); - while (count_fsb != 0) { + while (true) { /* - * Set up a transaction with which to allocate the - * backing store for the file. Do allocations in a - * loop until we get some space in the range we are - * interested in. The other space that might be allocated - * is in the delayed allocation extent on which we sit - * but before our buffer starts. + * Allocate in a loop because it may take several attempts to + * allocate real blocks for a contiguous delalloc extent if free + * space is sufficiently fragmented. Note that space for the + * extent and indirect blocks was reserved when the delalloc + * extent was created so there's no need to do so here. */ - nimaps = 0; - while (nimaps == 0) { - nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); - /* - * We have already reserved space for the extent and any - * indirect blocks when creating the delalloc extent, - * there is no need to reserve space in this transaction - * again. - */ - error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, - 0, XFS_TRANS_RESERVE, &tp); - if (error) - return error; - - xfs_ilock(ip, XFS_ILOCK_EXCL); - xfs_trans_ijoin(tp, ip, 0); - - /* - * it is possible that the extents have changed since - * we did the read call as we dropped the ilock for a - * while. We have to be careful about truncates or hole - * punchs here - we are not allowed to allocate - * non-delalloc blocks here. - * - * The only protection against truncation is the pages - * for the range we are being asked to convert are - * locked and hence a truncate will block on them - * first. - * - * As a result, if we go beyond the range we really - * need and hit an delalloc extent boundary followed by - * a hole while we have excess blocks in the map, we - * will fill the hole incorrectly and overrun the - * transaction reservation. - * - * Using a single map prevents this as we are forced to - * check each map we look for overlap with the desired - * range and abort as soon as we find it. Also, given - * that we only return a single map, having one beyond - * what we can return is probably a bit silly. - * - * We also need to check that we don't go beyond EOF; - * this is a truncate optimisation as a truncate sets - * the new file size before block on the pages we - * currently have locked under writeback. Because they - * are about to be tossed, we don't need to write them - * back.... - */ - nimaps = 1; - end_fsb = XFS_B_TO_FSB(mp, XFS_ISIZE(ip)); - error = xfs_bmap_last_offset(ip, &last_block, - XFS_DATA_FORK); - if (error) - goto trans_cancel; + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, + XFS_TRANS_RESERVE, &tp); + if (error) + return error; - last_block = XFS_FILEOFF_MAX(last_block, end_fsb); - if ((map_start_fsb + count_fsb) > last_block) { - count_fsb = last_block - map_start_fsb; - if (count_fsb == 0) { - error = -EAGAIN; - goto trans_cancel; - } - } + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, 0); - /* - * From this point onwards we overwrite the imap - * pointer that the caller gave to us. - */ - error = xfs_bmapi_write(tp, ip, map_start_fsb, - count_fsb, flags, nres, imap, - &nimaps); - if (error) - goto trans_cancel; + /* + * ilock was dropped since imap was populated which means it + * might no longer be valid. The current page is held locked so + * nothing could have removed the block backing offset_fsb. + * Attempt to allocate whatever delalloc extent currently backs + * offset_fsb and put the result in the imap pointer from the + * caller. We'll trim it down to the caller's most recently + * validated range before we return. + */ + error = xfs_bmapi_convert_delalloc(tp, ip, offset_fsb, + whichfork, imap); + if (error) + goto trans_cancel; - error = xfs_trans_commit(tp); - if (error) - goto error0; + error = xfs_trans_commit(tp); + if (error) + goto error0; - *seq = READ_ONCE(ifp->if_seq); - xfs_iunlock(ip, XFS_ILOCK_EXCL); - } + *seq = READ_ONCE(ifp->if_seq); + xfs_iunlock(ip, XFS_ILOCK_EXCL); /* - * See if we were able to allocate an extent that - * covers at least part of the callers request + * See if we were able to allocate an extent that covers at + * least part of the callers request. */ if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip))) return xfs_alert_fsblock_zero(ip, imap); @@ -812,15 +760,11 @@ xfs_iomap_write_allocate( (offset_fsb < (imap->br_startoff + imap->br_blockcount))) { XFS_STATS_INC(mp, xs_xstrat_quick); + xfs_trim_extent(imap, map_start_fsb, map_count_fsb); + ASSERT(offset_fsb >= imap->br_startoff && + offset_fsb < imap->br_startoff + imap->br_blockcount); return 0; } - - /* - * So far we have not mapped the requested part of the - * file, just surrounding data, try again. - */ - count_fsb -= imap->br_blockcount; - map_start_fsb = imap->br_startoff + imap->br_blockcount; } trans_cancel: |