diff options
Diffstat (limited to 'fs/xfs/xfs_iomap.c')
| -rw-r--r-- | fs/xfs/xfs_iomap.c | 518 |
1 files changed, 252 insertions, 266 deletions
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index 27c93b5f029d..63d323916bba 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -35,18 +35,40 @@ #define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \ << mp->m_writeio_log) -void +static int +xfs_alert_fsblock_zero( + xfs_inode_t *ip, + xfs_bmbt_irec_t *imap) +{ + xfs_alert_tag(ip->i_mount, XFS_PTAG_FSBLOCK_ZERO, + "Access to block zero in inode %llu " + "start_block: %llx start_off: %llx " + "blkcnt: %llx extent-state: %x", + (unsigned long long)ip->i_ino, + (unsigned long long)imap->br_startblock, + (unsigned long long)imap->br_startoff, + (unsigned long long)imap->br_blockcount, + imap->br_state); + return -EFSCORRUPTED; +} + +int xfs_bmbt_to_iomap( struct xfs_inode *ip, struct iomap *iomap, - struct xfs_bmbt_irec *imap) + struct xfs_bmbt_irec *imap, + bool shared) { struct xfs_mount *mp = ip->i_mount; + if (unlikely(!imap->br_startblock && !XFS_IS_REALTIME_INODE(ip))) + return xfs_alert_fsblock_zero(ip, imap); + if (imap->br_startblock == HOLESTARTBLOCK) { iomap->addr = IOMAP_NULL_ADDR; iomap->type = IOMAP_HOLE; - } else if (imap->br_startblock == DELAYSTARTBLOCK) { + } else if (imap->br_startblock == DELAYSTARTBLOCK || + isnullstartblock(imap->br_startblock)) { iomap->addr = IOMAP_NULL_ADDR; iomap->type = IOMAP_DELALLOC; } else { @@ -60,6 +82,13 @@ xfs_bmbt_to_iomap( iomap->length = XFS_FSB_TO_B(mp, imap->br_blockcount); iomap->bdev = xfs_find_bdev_for_inode(VFS_I(ip)); iomap->dax_dev = xfs_find_daxdev_for_inode(VFS_I(ip)); + + if (xfs_ipincount(ip) && + (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP)) + iomap->flags |= IOMAP_F_DIRTY; + if (shared) + iomap->flags |= IOMAP_F_SHARED; + return 0; } static void @@ -138,23 +167,6 @@ xfs_iomap_eof_align_last_fsb( return 0; } -STATIC int -xfs_alert_fsblock_zero( - xfs_inode_t *ip, - xfs_bmbt_irec_t *imap) -{ - xfs_alert_tag(ip->i_mount, XFS_PTAG_FSBLOCK_ZERO, - "Access to block zero in inode %llu " - "start_block: %llx start_off: %llx " - "blkcnt: %llx extent-state: %x", - (unsigned long long)ip->i_ino, - (unsigned long long)imap->br_startblock, - (unsigned long long)imap->br_startoff, - (unsigned long long)imap->br_blockcount, - imap->br_state); - return -EFSCORRUPTED; -} - int xfs_iomap_write_direct( xfs_inode_t *ip, @@ -383,12 +395,13 @@ xfs_quota_calc_throttle( STATIC xfs_fsblock_t xfs_iomap_prealloc_size( struct xfs_inode *ip, + int whichfork, loff_t offset, loff_t count, struct xfs_iext_cursor *icur) { struct xfs_mount *mp = ip->i_mount; - struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK); + struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork); xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); struct xfs_bmbt_irec prev; int shift = 0; @@ -522,15 +535,16 @@ xfs_file_iomap_begin_delay( { struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; - struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK); xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); xfs_fileoff_t maxbytes_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes); xfs_fileoff_t end_fsb; - int error = 0, eof = 0; - struct xfs_bmbt_irec got; - struct xfs_iext_cursor icur; + struct xfs_bmbt_irec imap, cmap; + struct xfs_iext_cursor icur, ccur; xfs_fsblock_t prealloc_blocks = 0; + bool eof = false, cow_eof = false, shared = false; + int whichfork = XFS_DATA_FORK; + int error = 0; ASSERT(!XFS_IS_REALTIME_INODE(ip)); ASSERT(!xfs_get_extsz_hint(ip)); @@ -548,7 +562,7 @@ xfs_file_iomap_begin_delay( XFS_STATS_INC(mp, xs_blk_mapw); - if (!(ifp->if_flags & XFS_IFEXTENTS)) { + if (!(ip->i_df.if_flags & XFS_IFEXTENTS)) { error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK); if (error) goto out_unlock; @@ -556,53 +570,101 @@ xfs_file_iomap_begin_delay( end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb); - eof = !xfs_iext_lookup_extent(ip, ifp, offset_fsb, &icur, &got); + /* + * Search the data fork fork first to look up our source mapping. We + * always need the data fork map, as we have to return it to the + * iomap code so that the higher level write code can read data in to + * perform read-modify-write cycles for unaligned writes. + */ + eof = !xfs_iext_lookup_extent(ip, &ip->i_df, offset_fsb, &icur, &imap); if (eof) - got.br_startoff = end_fsb; /* fake hole until the end */ + imap.br_startoff = end_fsb; /* fake hole until the end */ + + /* We never need to allocate blocks for zeroing a hole. */ + if ((flags & IOMAP_ZERO) && imap.br_startoff > offset_fsb) { + xfs_hole_to_iomap(ip, iomap, offset_fsb, imap.br_startoff); + goto out_unlock; + } - if (got.br_startoff <= offset_fsb) { + /* + * Search the COW fork extent list even if we did not find a data fork + * extent. This serves two purposes: first this implements the + * speculative preallocation using cowextsize, so that we also unshare + * block adjacent to shared blocks instead of just the shared blocks + * themselves. Second the lookup in the extent list is generally faster + * than going out to the shared extent tree. + */ + if (xfs_is_cow_inode(ip)) { + if (!ip->i_cowfp) { + ASSERT(!xfs_is_reflink_inode(ip)); + xfs_ifork_init_cow(ip); + } + cow_eof = !xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, + &ccur, &cmap); + if (!cow_eof && cmap.br_startoff <= offset_fsb) { + trace_xfs_reflink_cow_found(ip, &cmap); + whichfork = XFS_COW_FORK; + goto done; + } + } + + if (imap.br_startoff <= offset_fsb) { /* * For reflink files we may need a delalloc reservation when * overwriting shared extents. This includes zeroing of * existing extents that contain data. */ - if (xfs_is_reflink_inode(ip) && - ((flags & IOMAP_WRITE) || - got.br_state != XFS_EXT_UNWRITTEN)) { - xfs_trim_extent(&got, offset_fsb, end_fsb - offset_fsb); - error = xfs_reflink_reserve_cow(ip, &got); - if (error) - goto out_unlock; + if (!xfs_is_cow_inode(ip) || + ((flags & IOMAP_ZERO) && imap.br_state != XFS_EXT_NORM)) { + trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK, + &imap); + goto done; } - trace_xfs_iomap_found(ip, offset, count, 0, &got); - goto done; - } + xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb); - if (flags & IOMAP_ZERO) { - xfs_hole_to_iomap(ip, iomap, offset_fsb, got.br_startoff); - goto out_unlock; + /* Trim the mapping to the nearest shared extent boundary. */ + error = xfs_inode_need_cow(ip, &imap, &shared); + if (error) + goto out_unlock; + + /* Not shared? Just report the (potentially capped) extent. */ + if (!shared) { + trace_xfs_iomap_found(ip, offset, count, XFS_DATA_FORK, + &imap); + goto done; + } + + /* + * Fork all the shared blocks from our write offset until the + * end of the extent. + */ + whichfork = XFS_COW_FORK; + end_fsb = imap.br_startoff + imap.br_blockcount; + } else { + /* + * We cap the maximum length we map here to MAX_WRITEBACK_PAGES + * pages to keep the chunks of work done where somewhat + * symmetric with the work writeback does. This is a completely + * arbitrary number pulled out of thin air. + * + * Note that the values needs to be less than 32-bits wide until + * the lower level functions are updated. + */ + count = min_t(loff_t, count, 1024 * PAGE_SIZE); + end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb); + + if (xfs_is_always_cow_inode(ip)) + whichfork = XFS_COW_FORK; } error = xfs_qm_dqattach_locked(ip, false); if (error) goto out_unlock; - /* - * We cap the maximum length we map here to MAX_WRITEBACK_PAGES pages - * to keep the chunks of work done where somewhat symmetric with the - * work writeback does. This is a completely arbitrary number pulled - * out of thin air as a best guess for initial testing. - * - * Note that the values needs to be less than 32-bits wide until - * the lower level functions are updated. - */ - count = min_t(loff_t, count, 1024 * PAGE_SIZE); - end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb); - if (eof) { - prealloc_blocks = xfs_iomap_prealloc_size(ip, offset, count, - &icur); + prealloc_blocks = xfs_iomap_prealloc_size(ip, whichfork, offset, + count, &icur); if (prealloc_blocks) { xfs_extlen_t align; xfs_off_t end_offset; @@ -623,9 +685,11 @@ xfs_file_iomap_begin_delay( } retry: - error = xfs_bmapi_reserve_delalloc(ip, XFS_DATA_FORK, offset_fsb, - end_fsb - offset_fsb, prealloc_blocks, &got, &icur, - eof); + error = xfs_bmapi_reserve_delalloc(ip, whichfork, offset_fsb, + end_fsb - offset_fsb, prealloc_blocks, + whichfork == XFS_DATA_FORK ? &imap : &cmap, + whichfork == XFS_DATA_FORK ? &icur : &ccur, + whichfork == XFS_DATA_FORK ? eof : cow_eof); switch (error) { case 0: break; @@ -647,186 +711,22 @@ retry: * them out if the write happens to fail. */ iomap->flags |= IOMAP_F_NEW; - trace_xfs_iomap_alloc(ip, offset, count, 0, &got); + trace_xfs_iomap_alloc(ip, offset, count, whichfork, + whichfork == XFS_DATA_FORK ? &imap : &cmap); done: - if (isnullstartblock(got.br_startblock)) - got.br_startblock = DELAYSTARTBLOCK; - - if (!got.br_startblock) { - error = xfs_alert_fsblock_zero(ip, &got); - if (error) + if (whichfork == XFS_COW_FORK) { + if (imap.br_startoff > offset_fsb) { + xfs_trim_extent(&cmap, offset_fsb, + imap.br_startoff - offset_fsb); + error = xfs_bmbt_to_iomap(ip, iomap, &cmap, true); goto out_unlock; - } - - xfs_bmbt_to_iomap(ip, iomap, &got); - -out_unlock: - xfs_iunlock(ip, XFS_ILOCK_EXCL); - return error; -} - -/* - * Pass in a delayed allocate extent, convert it to real extents; - * return to the caller the extent we create which maps on top of - * the originating callers request. - * - * Called without a lock on the inode. - * - * We no longer bother to look at the incoming map - all we have to - * guarantee is that whatever we allocate fills the required range. - */ -int -xfs_iomap_write_allocate( - xfs_inode_t *ip, - int whichfork, - xfs_off_t offset, - xfs_bmbt_irec_t *imap, - unsigned int *cow_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; - - /* - * Make sure that the dquots are there. - */ - error = xfs_qm_dqattach(ip); - if (error) - return error; - - offset_fsb = XFS_B_TO_FSBT(mp, offset); - count_fsb = imap->br_blockcount; - map_start_fsb = imap->br_startoff; - - XFS_STATS_ADD(mp, xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb)); - - while (count_fsb != 0) { - /* - * 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. - */ - 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; - - 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; - } - } - - /* - * 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; - - error = xfs_trans_commit(tp); - if (error) - goto error0; - - if (whichfork == XFS_COW_FORK) - *cow_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 - */ - if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip))) - return xfs_alert_fsblock_zero(ip, imap); - - if ((offset_fsb >= imap->br_startoff) && - (offset_fsb < (imap->br_startoff + - imap->br_blockcount))) { - XFS_STATS_INC(mp, xs_xstrat_quick); - 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; + /* ensure we only report blocks we have a reservation for */ + xfs_trim_extent(&imap, cmap.br_startoff, cmap.br_blockcount); + shared = true; } - -trans_cancel: - xfs_trans_cancel(tp); -error0: + error = xfs_bmbt_to_iomap(ip, iomap, &imap, shared); +out_unlock: xfs_iunlock(ip, XFS_ILOCK_EXCL); return error; } @@ -975,7 +875,7 @@ xfs_ilock_for_iomap( * COW writes may allocate delalloc space or convert unwritten COW * extents, so we need to make sure to take the lock exclusively here. */ - if (xfs_is_reflink_inode(ip) && is_write) { + if (xfs_is_cow_inode(ip) && is_write) { /* * FIXME: It could still overwrite on unshared extents and not * need allocation. @@ -1009,7 +909,7 @@ relock: * check, so if we got ILOCK_SHARED for a write and but we're now a * reflink inode we have to switch to ILOCK_EXCL and relock. */ - if (mode == XFS_ILOCK_SHARED && is_write && xfs_is_reflink_inode(ip)) { + if (mode == XFS_ILOCK_SHARED && is_write && xfs_is_cow_inode(ip)) { xfs_iunlock(ip, mode); mode = XFS_ILOCK_EXCL; goto relock; @@ -1081,23 +981,33 @@ xfs_file_iomap_begin( * Break shared extents if necessary. Checks for non-blocking IO have * been done up front, so we don't need to do them here. */ - if (xfs_is_reflink_inode(ip)) { + if (xfs_is_cow_inode(ip)) { + struct xfs_bmbt_irec cmap; + bool directio = (flags & IOMAP_DIRECT); + /* if zeroing doesn't need COW allocation, then we are done. */ if ((flags & IOMAP_ZERO) && !needs_cow_for_zeroing(&imap, nimaps)) goto out_found; - if (flags & IOMAP_DIRECT) { - /* may drop and re-acquire the ilock */ - error = xfs_reflink_allocate_cow(ip, &imap, &shared, - &lockmode); - if (error) - goto out_unlock; - } else { - error = xfs_reflink_reserve_cow(ip, &imap); - if (error) - goto out_unlock; - } + /* may drop and re-acquire the ilock */ + cmap = imap; + error = xfs_reflink_allocate_cow(ip, &cmap, &shared, &lockmode, + directio); + if (error) + goto out_unlock; + + /* + * For buffered writes we need to report the address of the + * previous block (if there was any) so that the higher level + * write code can perform read-modify-write operations; we + * won't need the CoW fork mapping until writeback. For direct + * I/O, which must be block aligned, we need to report the + * newly allocated address. If the data fork has a hole, copy + * the COW fork mapping to avoid allocating to the data fork. + */ + if (directio || imap.br_startblock == HOLESTARTBLOCK) + imap = cmap; end_fsb = imap.br_startoff + imap.br_blockcount; length = XFS_FSB_TO_B(mp, end_fsb) - offset; @@ -1139,23 +1049,15 @@ xfs_file_iomap_begin( return error; iomap->flags |= IOMAP_F_NEW; - trace_xfs_iomap_alloc(ip, offset, length, 0, &imap); + trace_xfs_iomap_alloc(ip, offset, length, XFS_DATA_FORK, &imap); out_finish: - if (xfs_ipincount(ip) && (ip->i_itemp->ili_fsync_fields - & ~XFS_ILOG_TIMESTAMP)) - iomap->flags |= IOMAP_F_DIRTY; - - xfs_bmbt_to_iomap(ip, iomap, &imap); - - if (shared) - iomap->flags |= IOMAP_F_SHARED; - return 0; + return xfs_bmbt_to_iomap(ip, iomap, &imap, shared); out_found: ASSERT(nimaps); xfs_iunlock(ip, lockmode); - trace_xfs_iomap_found(ip, offset, length, 0, &imap); + trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap); goto out_finish; out_unlock: @@ -1241,6 +1143,92 @@ const struct iomap_ops xfs_iomap_ops = { }; static int +xfs_seek_iomap_begin( + struct inode *inode, + loff_t offset, + loff_t length, + unsigned flags, + struct iomap *iomap) +{ + struct xfs_inode *ip = XFS_I(inode); + struct xfs_mount *mp = ip->i_mount; + xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); + xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + length); + xfs_fileoff_t cow_fsb = NULLFILEOFF, data_fsb = NULLFILEOFF; + struct xfs_iext_cursor icur; + struct xfs_bmbt_irec imap, cmap; + int error = 0; + unsigned lockmode; + + if (XFS_FORCED_SHUTDOWN(mp)) + return -EIO; + + lockmode = xfs_ilock_data_map_shared(ip); + if (!(ip->i_df.if_flags & XFS_IFEXTENTS)) { + error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK); + if (error) + goto out_unlock; + } + + if (xfs_iext_lookup_extent(ip, &ip->i_df, offset_fsb, &icur, &imap)) { + /* + * If we found a data extent we are done. + */ + if (imap.br_startoff <= offset_fsb) + goto done; + data_fsb = imap.br_startoff; + } else { + /* + * Fake a hole until the end of the file. + */ + data_fsb = min(XFS_B_TO_FSB(mp, offset + length), + XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes)); + } + + /* + * If a COW fork extent covers the hole, report it - capped to the next + * data fork extent: + */ + if (xfs_inode_has_cow_data(ip) && + xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &cmap)) + cow_fsb = cmap.br_startoff; + if (cow_fsb != NULLFILEOFF && cow_fsb <= offset_fsb) { + if (data_fsb < cow_fsb + cmap.br_blockcount) + end_fsb = min(end_fsb, data_fsb); + xfs_trim_extent(&cmap, offset_fsb, end_fsb); + error = xfs_bmbt_to_iomap(ip, iomap, &cmap, true); + /* + * This is a COW extent, so we must probe the page cache + * because there could be dirty page cache being backed + * by this extent. + */ + iomap->type = IOMAP_UNWRITTEN; + goto out_unlock; + } + + /* + * Else report a hole, capped to the next found data or COW extent. + */ + if (cow_fsb != NULLFILEOFF && cow_fsb < data_fsb) + imap.br_blockcount = cow_fsb - offset_fsb; + else + imap.br_blockcount = data_fsb - offset_fsb; + imap.br_startoff = offset_fsb; + imap.br_startblock = HOLESTARTBLOCK; + imap.br_state = XFS_EXT_NORM; +done: + xfs_trim_extent(&imap, offset_fsb, end_fsb); + error = xfs_bmbt_to_iomap(ip, iomap, &imap, false); +out_unlock: + xfs_iunlock(ip, lockmode); + return error; +} + +const struct iomap_ops xfs_seek_iomap_ops = { + .iomap_begin = xfs_seek_iomap_begin, +}; + +static int xfs_xattr_iomap_begin( struct inode *inode, loff_t offset, @@ -1273,12 +1261,10 @@ xfs_xattr_iomap_begin( out_unlock: xfs_iunlock(ip, lockmode); - if (!error) { - ASSERT(nimaps); - xfs_bmbt_to_iomap(ip, iomap, &imap); - } - - return error; + if (error) + return error; + ASSERT(nimaps); + return xfs_bmbt_to_iomap(ip, iomap, &imap, false); } const struct iomap_ops xfs_xattr_iomap_ops = { |