| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (c) 2000-2006 Silicon Graphics, Inc. |
| * Copyright (c) 2016-2018 Christoph Hellwig. |
| * All Rights Reserved. |
| */ |
| #include "xfs.h" |
| #include "xfs_fs.h" |
| #include "xfs_shared.h" |
| #include "xfs_format.h" |
| #include "xfs_log_format.h" |
| #include "xfs_trans_resv.h" |
| #include "xfs_mount.h" |
| #include "xfs_inode.h" |
| #include "xfs_btree.h" |
| #include "xfs_bmap_btree.h" |
| #include "xfs_bmap.h" |
| #include "xfs_bmap_util.h" |
| #include "xfs_errortag.h" |
| #include "xfs_error.h" |
| #include "xfs_trans.h" |
| #include "xfs_trans_space.h" |
| #include "xfs_inode_item.h" |
| #include "xfs_iomap.h" |
| #include "xfs_trace.h" |
| #include "xfs_quota.h" |
| #include "xfs_dquot_item.h" |
| #include "xfs_dquot.h" |
| #include "xfs_reflink.h" |
| |
| |
| #define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \ |
| << mp->m_writeio_log) |
| |
| 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, |
| 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 || |
| isnullstartblock(imap->br_startblock)) { |
| iomap->addr = IOMAP_NULL_ADDR; |
| iomap->type = IOMAP_DELALLOC; |
| } else { |
| iomap->addr = BBTOB(xfs_fsb_to_db(ip, imap->br_startblock)); |
| if (imap->br_state == XFS_EXT_UNWRITTEN) |
| iomap->type = IOMAP_UNWRITTEN; |
| else |
| iomap->type = IOMAP_MAPPED; |
| } |
| iomap->offset = XFS_FSB_TO_B(mp, imap->br_startoff); |
| 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 |
| xfs_hole_to_iomap( |
| struct xfs_inode *ip, |
| struct iomap *iomap, |
| xfs_fileoff_t offset_fsb, |
| xfs_fileoff_t end_fsb) |
| { |
| iomap->addr = IOMAP_NULL_ADDR; |
| iomap->type = IOMAP_HOLE; |
| iomap->offset = XFS_FSB_TO_B(ip->i_mount, offset_fsb); |
| iomap->length = XFS_FSB_TO_B(ip->i_mount, end_fsb - offset_fsb); |
| iomap->bdev = xfs_find_bdev_for_inode(VFS_I(ip)); |
| iomap->dax_dev = xfs_find_daxdev_for_inode(VFS_I(ip)); |
| } |
| |
| xfs_extlen_t |
| xfs_eof_alignment( |
| struct xfs_inode *ip, |
| xfs_extlen_t extsize) |
| { |
| struct xfs_mount *mp = ip->i_mount; |
| xfs_extlen_t align = 0; |
| |
| if (!XFS_IS_REALTIME_INODE(ip)) { |
| /* |
| * Round up the allocation request to a stripe unit |
| * (m_dalign) boundary if the file size is >= stripe unit |
| * size, and we are allocating past the allocation eof. |
| * |
| * If mounted with the "-o swalloc" option the alignment is |
| * increased from the strip unit size to the stripe width. |
| */ |
| if (mp->m_swidth && (mp->m_flags & XFS_MOUNT_SWALLOC)) |
| align = mp->m_swidth; |
| else if (mp->m_dalign) |
| align = mp->m_dalign; |
| |
| if (align && XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, align)) |
| align = 0; |
| } |
| |
| /* |
| * Always round up the allocation request to an extent boundary |
| * (when file on a real-time subvolume or has di_extsize hint). |
| */ |
| if (extsize) { |
| if (align) |
| align = roundup_64(align, extsize); |
| else |
| align = extsize; |
| } |
| |
| return align; |
| } |
| |
| STATIC int |
| xfs_iomap_eof_align_last_fsb( |
| struct xfs_inode *ip, |
| xfs_extlen_t extsize, |
| xfs_fileoff_t *last_fsb) |
| { |
| xfs_extlen_t align = xfs_eof_alignment(ip, extsize); |
| |
| if (align) { |
| xfs_fileoff_t new_last_fsb = roundup_64(*last_fsb, align); |
| int eof, error; |
| |
| error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof); |
| if (error) |
| return error; |
| if (eof) |
| *last_fsb = new_last_fsb; |
| } |
| return 0; |
| } |
| |
| int |
| xfs_iomap_write_direct( |
| xfs_inode_t *ip, |
| xfs_off_t offset, |
| size_t count, |
| xfs_bmbt_irec_t *imap, |
| int nmaps) |
| { |
| xfs_mount_t *mp = ip->i_mount; |
| xfs_fileoff_t offset_fsb; |
| xfs_fileoff_t last_fsb; |
| xfs_filblks_t count_fsb, resaligned; |
| xfs_extlen_t extsz; |
| int nimaps; |
| int quota_flag; |
| int rt; |
| xfs_trans_t *tp; |
| uint qblocks, resblks, resrtextents; |
| int error; |
| int lockmode; |
| int bmapi_flags = XFS_BMAPI_PREALLOC; |
| uint tflags = 0; |
| |
| rt = XFS_IS_REALTIME_INODE(ip); |
| extsz = xfs_get_extsz_hint(ip); |
| lockmode = XFS_ILOCK_SHARED; /* locked by caller */ |
| |
| ASSERT(xfs_isilocked(ip, lockmode)); |
| |
| offset_fsb = XFS_B_TO_FSBT(mp, offset); |
| last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count))); |
| if ((offset + count) > XFS_ISIZE(ip)) { |
| /* |
| * Assert that the in-core extent list is present since this can |
| * call xfs_iread_extents() and we only have the ilock shared. |
| * This should be safe because the lock was held around a bmapi |
| * call in the caller and we only need it to access the in-core |
| * list. |
| */ |
| ASSERT(XFS_IFORK_PTR(ip, XFS_DATA_FORK)->if_flags & |
| XFS_IFEXTENTS); |
| error = xfs_iomap_eof_align_last_fsb(ip, extsz, &last_fsb); |
| if (error) |
| goto out_unlock; |
| } else { |
| if (nmaps && (imap->br_startblock == HOLESTARTBLOCK)) |
| last_fsb = min(last_fsb, (xfs_fileoff_t) |
| imap->br_blockcount + |
| imap->br_startoff); |
| } |
| count_fsb = last_fsb - offset_fsb; |
| ASSERT(count_fsb > 0); |
| resaligned = xfs_aligned_fsb_count(offset_fsb, count_fsb, extsz); |
| |
| if (unlikely(rt)) { |
| resrtextents = qblocks = resaligned; |
| resrtextents /= mp->m_sb.sb_rextsize; |
| resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0); |
| quota_flag = XFS_QMOPT_RES_RTBLKS; |
| } else { |
| resrtextents = 0; |
| resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned); |
| quota_flag = XFS_QMOPT_RES_REGBLKS; |
| } |
| |
| /* |
| * Drop the shared lock acquired by the caller, attach the dquot if |
| * necessary and move on to transaction setup. |
| */ |
| xfs_iunlock(ip, lockmode); |
| error = xfs_qm_dqattach(ip); |
| if (error) |
| return error; |
| |
| /* |
| * For DAX, we do not allocate unwritten extents, but instead we zero |
| * the block before we commit the transaction. Ideally we'd like to do |
| * this outside the transaction context, but if we commit and then crash |
| * we may not have zeroed the blocks and this will be exposed on |
| * recovery of the allocation. Hence we must zero before commit. |
| * |
| * Further, if we are mapping unwritten extents here, we need to zero |
| * and convert them to written so that we don't need an unwritten extent |
| * callback for DAX. This also means that we need to be able to dip into |
| * the reserve block pool for bmbt block allocation if there is no space |
| * left but we need to do unwritten extent conversion. |
| */ |
| if (IS_DAX(VFS_I(ip))) { |
| bmapi_flags = XFS_BMAPI_CONVERT | XFS_BMAPI_ZERO; |
| if (imap->br_state == XFS_EXT_UNWRITTEN) { |
| tflags |= XFS_TRANS_RESERVE; |
| resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1; |
| } |
| } |
| error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, resrtextents, |
| tflags, &tp); |
| if (error) |
| return error; |
| |
| lockmode = XFS_ILOCK_EXCL; |
| xfs_ilock(ip, lockmode); |
| |
| error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks, 0, quota_flag); |
| if (error) |
| goto out_trans_cancel; |
| |
| xfs_trans_ijoin(tp, ip, 0); |
| |
| /* |
| * From this point onwards we overwrite the imap pointer that the |
| * caller gave to us. |
| */ |
| nimaps = 1; |
| error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, |
| bmapi_flags, resblks, imap, &nimaps); |
| if (error) |
| goto out_res_cancel; |
| |
| /* |
| * Complete the transaction |
| */ |
| error = xfs_trans_commit(tp); |
| if (error) |
| goto out_unlock; |
| |
| /* |
| * Copy any maps to caller's array and return any error. |
| */ |
| if (nimaps == 0) { |
| error = -ENOSPC; |
| goto out_unlock; |
| } |
| |
| if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip))) |
| error = xfs_alert_fsblock_zero(ip, imap); |
| |
| out_unlock: |
| xfs_iunlock(ip, lockmode); |
| return error; |
| |
| out_res_cancel: |
| xfs_trans_unreserve_quota_nblks(tp, ip, (long)qblocks, 0, quota_flag); |
| out_trans_cancel: |
| xfs_trans_cancel(tp); |
| goto out_unlock; |
| } |
| |
| STATIC bool |
| xfs_quota_need_throttle( |
| struct xfs_inode *ip, |
| int type, |
| xfs_fsblock_t alloc_blocks) |
| { |
| struct xfs_dquot *dq = xfs_inode_dquot(ip, type); |
| |
| if (!dq || !xfs_this_quota_on(ip->i_mount, type)) |
| return false; |
| |
| /* no hi watermark, no throttle */ |
| if (!dq->q_prealloc_hi_wmark) |
| return false; |
| |
| /* under the lo watermark, no throttle */ |
| if (dq->q_res_bcount + alloc_blocks < dq->q_prealloc_lo_wmark) |
| return false; |
| |
| return true; |
| } |
| |
| STATIC void |
| xfs_quota_calc_throttle( |
| struct xfs_inode *ip, |
| int type, |
| xfs_fsblock_t *qblocks, |
| int *qshift, |
| int64_t *qfreesp) |
| { |
| int64_t freesp; |
| int shift = 0; |
| struct xfs_dquot *dq = xfs_inode_dquot(ip, type); |
| |
| /* no dq, or over hi wmark, squash the prealloc completely */ |
| if (!dq || dq->q_res_bcount >= dq->q_prealloc_hi_wmark) { |
| *qblocks = 0; |
| *qfreesp = 0; |
| return; |
| } |
| |
| freesp = dq->q_prealloc_hi_wmark - dq->q_res_bcount; |
| if (freesp < dq->q_low_space[XFS_QLOWSP_5_PCNT]) { |
| shift = 2; |
| if (freesp < dq->q_low_space[XFS_QLOWSP_3_PCNT]) |
| shift += 2; |
| if (freesp < dq->q_low_space[XFS_QLOWSP_1_PCNT]) |
| shift += 2; |
| } |
| |
| if (freesp < *qfreesp) |
| *qfreesp = freesp; |
| |
| /* only overwrite the throttle values if we are more aggressive */ |
| if ((freesp >> shift) < (*qblocks >> *qshift)) { |
| *qblocks = freesp; |
| *qshift = shift; |
| } |
| } |
| |
| /* |
| * If we are doing a write at the end of the file and there are no allocations |
| * past this one, then extend the allocation out to the file system's write |
| * iosize. |
| * |
| * If we don't have a user specified preallocation size, dynamically increase |
| * the preallocation size as the size of the file grows. Cap the maximum size |
| * at a single extent or less if the filesystem is near full. The closer the |
| * filesystem is to full, the smaller the maximum prealocation. |
| * |
| * As an exception we don't do any preallocation at all if the file is smaller |
| * than the minimum preallocation and we are using the default dynamic |
| * preallocation scheme, as it is likely this is the only write to the file that |
| * is going to be done. |
| * |
| * We clean up any extra space left over when the file is closed in |
| * xfs_inactive(). |
| */ |
| 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, whichfork); |
| xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); |
| struct xfs_bmbt_irec prev; |
| int shift = 0; |
| int64_t freesp; |
| xfs_fsblock_t qblocks; |
| int qshift = 0; |
| xfs_fsblock_t alloc_blocks = 0; |
| |
| if (offset + count <= XFS_ISIZE(ip)) |
| return 0; |
| |
| if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE) && |
| (XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_writeio_blocks))) |
| return 0; |
| |
| /* |
| * If an explicit allocsize is set, the file is small, or we |
| * are writing behind a hole, then use the minimum prealloc: |
| */ |
| if ((mp->m_flags & XFS_MOUNT_DFLT_IOSIZE) || |
| XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_dalign) || |
| !xfs_iext_peek_prev_extent(ifp, icur, &prev) || |
| prev.br_startoff + prev.br_blockcount < offset_fsb) |
| return mp->m_writeio_blocks; |
| |
| /* |
| * Determine the initial size of the preallocation. We are beyond the |
| * current EOF here, but we need to take into account whether this is |
| * a sparse write or an extending write when determining the |
| * preallocation size. Hence we need to look up the extent that ends |
| * at the current write offset and use the result to determine the |
| * preallocation size. |
| * |
| * If the extent is a hole, then preallocation is essentially disabled. |
| * Otherwise we take the size of the preceding data extent as the basis |
| * for the preallocation size. If the size of the extent is greater than |
| * half the maximum extent length, then use the current offset as the |
| * basis. This ensures that for large files the preallocation size |
| * always extends to MAXEXTLEN rather than falling short due to things |
| * like stripe unit/width alignment of real extents. |
| */ |
| if (prev.br_blockcount <= (MAXEXTLEN >> 1)) |
| alloc_blocks = prev.br_blockcount << 1; |
| else |
| alloc_blocks = XFS_B_TO_FSB(mp, offset); |
| if (!alloc_blocks) |
| goto check_writeio; |
| qblocks = alloc_blocks; |
| |
| /* |
| * MAXEXTLEN is not a power of two value but we round the prealloc down |
| * to the nearest power of two value after throttling. To prevent the |
| * round down from unconditionally reducing the maximum supported prealloc |
| * size, we round up first, apply appropriate throttling, round down and |
| * cap the value to MAXEXTLEN. |
| */ |
| alloc_blocks = XFS_FILEOFF_MIN(roundup_pow_of_two(MAXEXTLEN), |
| alloc_blocks); |
| |
| freesp = percpu_counter_read_positive(&mp->m_fdblocks); |
| if (freesp < mp->m_low_space[XFS_LOWSP_5_PCNT]) { |
| shift = 2; |
| if (freesp < mp->m_low_space[XFS_LOWSP_4_PCNT]) |
| shift++; |
| if (freesp < mp->m_low_space[XFS_LOWSP_3_PCNT]) |
| shift++; |
| if (freesp < mp->m_low_space[XFS_LOWSP_2_PCNT]) |
| shift++; |
| if (freesp < mp->m_low_space[XFS_LOWSP_1_PCNT]) |
| shift++; |
| } |
| |
| /* |
| * Check each quota to cap the prealloc size, provide a shift value to |
| * throttle with and adjust amount of available space. |
| */ |
| if (xfs_quota_need_throttle(ip, XFS_DQ_USER, alloc_blocks)) |
| xfs_quota_calc_throttle(ip, XFS_DQ_USER, &qblocks, &qshift, |
| &freesp); |
| if (xfs_quota_need_throttle(ip, XFS_DQ_GROUP, alloc_blocks)) |
| xfs_quota_calc_throttle(ip, XFS_DQ_GROUP, &qblocks, &qshift, |
| &freesp); |
| if (xfs_quota_need_throttle(ip, XFS_DQ_PROJ, alloc_blocks)) |
| xfs_quota_calc_throttle(ip, XFS_DQ_PROJ, &qblocks, &qshift, |
| &freesp); |
| |
| /* |
| * The final prealloc size is set to the minimum of free space available |
| * in each of the quotas and the overall filesystem. |
| * |
| * The shift throttle value is set to the maximum value as determined by |
| * the global low free space values and per-quota low free space values. |
| */ |
| alloc_blocks = min(alloc_blocks, qblocks); |
| shift = max(shift, qshift); |
| |
| if (shift) |
| alloc_blocks >>= shift; |
| /* |
| * rounddown_pow_of_two() returns an undefined result if we pass in |
| * alloc_blocks = 0. |
| */ |
| if (alloc_blocks) |
| alloc_blocks = rounddown_pow_of_two(alloc_blocks); |
| if (alloc_blocks > MAXEXTLEN) |
| alloc_blocks = MAXEXTLEN; |
| |
| /* |
| * If we are still trying to allocate more space than is |
| * available, squash the prealloc hard. This can happen if we |
| * have a large file on a small filesystem and the above |
| * lowspace thresholds are smaller than MAXEXTLEN. |
| */ |
| while (alloc_blocks && alloc_blocks >= freesp) |
| alloc_blocks >>= 4; |
| check_writeio: |
| if (alloc_blocks < mp->m_writeio_blocks) |
| alloc_blocks = mp->m_writeio_blocks; |
| trace_xfs_iomap_prealloc_size(ip, alloc_blocks, shift, |
| mp->m_writeio_blocks); |
| return alloc_blocks; |
| } |
| |
| static int |
| xfs_file_iomap_begin_delay( |
| struct inode *inode, |
| loff_t offset, |
| loff_t count, |
| 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 maxbytes_fsb = |
| XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes); |
| xfs_fileoff_t end_fsb; |
| 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)); |
| |
| xfs_ilock(ip, XFS_ILOCK_EXCL); |
| |
| if (unlikely(XFS_TEST_ERROR( |
| (XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_EXTENTS && |
| XFS_IFORK_FORMAT(ip, XFS_DATA_FORK) != XFS_DINODE_FMT_BTREE), |
| mp, XFS_ERRTAG_BMAPIFORMAT))) { |
| XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp); |
| error = -EFSCORRUPTED; |
| goto out_unlock; |
| } |
| |
| XFS_STATS_INC(mp, xs_blk_mapw); |
| |
| if (!(ip->i_df.if_flags & XFS_IFEXTENTS)) { |
| error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK); |
| if (error) |
| goto out_unlock; |
| } |
| |
| end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb); |
| |
| /* |
| * 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) |
| 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; |
| } |
| |
| /* |
| * 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_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; |
| } |
| |
| xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb); |
| |
| /* 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; |
| |
| if (eof) { |
| prealloc_blocks = xfs_iomap_prealloc_size(ip, whichfork, offset, |
| count, &icur); |
| if (prealloc_blocks) { |
| xfs_extlen_t align; |
| xfs_off_t end_offset; |
| xfs_fileoff_t p_end_fsb; |
| |
| end_offset = XFS_WRITEIO_ALIGN(mp, offset + count - 1); |
| p_end_fsb = XFS_B_TO_FSBT(mp, end_offset) + |
| prealloc_blocks; |
| |
| align = xfs_eof_alignment(ip, 0); |
| if (align) |
| p_end_fsb = roundup_64(p_end_fsb, align); |
| |
| p_end_fsb = min(p_end_fsb, maxbytes_fsb); |
| ASSERT(p_end_fsb > offset_fsb); |
| prealloc_blocks = p_end_fsb - end_fsb; |
| } |
| } |
| |
| retry: |
| 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; |
| case -ENOSPC: |
| case -EDQUOT: |
| /* retry without any preallocation */ |
| trace_xfs_delalloc_enospc(ip, offset, count); |
| if (prealloc_blocks) { |
| prealloc_blocks = 0; |
| goto retry; |
| } |
| /*FALLTHRU*/ |
| default: |
| goto out_unlock; |
| } |
| |
| /* |
| * Flag newly allocated delalloc blocks with IOMAP_F_NEW so we punch |
| * them out if the write happens to fail. |
| */ |
| iomap->flags |= IOMAP_F_NEW; |
| trace_xfs_iomap_alloc(ip, offset, count, whichfork, |
| whichfork == XFS_DATA_FORK ? &imap : &cmap); |
| done: |
| 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; |
| } |
| /* ensure we only report blocks we have a reservation for */ |
| xfs_trim_extent(&imap, cmap.br_startoff, cmap.br_blockcount); |
| shared = true; |
| } |
| error = xfs_bmbt_to_iomap(ip, iomap, &imap, shared); |
| out_unlock: |
| xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| return error; |
| } |
| |
| int |
| xfs_iomap_write_unwritten( |
| xfs_inode_t *ip, |
| xfs_off_t offset, |
| xfs_off_t count, |
| bool update_isize) |
| { |
| xfs_mount_t *mp = ip->i_mount; |
| xfs_fileoff_t offset_fsb; |
| xfs_filblks_t count_fsb; |
| xfs_filblks_t numblks_fsb; |
| int nimaps; |
| xfs_trans_t *tp; |
| xfs_bmbt_irec_t imap; |
| struct inode *inode = VFS_I(ip); |
| xfs_fsize_t i_size; |
| uint resblks; |
| int error; |
| |
| trace_xfs_unwritten_convert(ip, offset, count); |
| |
| offset_fsb = XFS_B_TO_FSBT(mp, offset); |
| count_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count); |
| count_fsb = (xfs_filblks_t)(count_fsb - offset_fsb); |
| |
| /* |
| * Reserve enough blocks in this transaction for two complete extent |
| * btree splits. We may be converting the middle part of an unwritten |
| * extent and in this case we will insert two new extents in the btree |
| * each of which could cause a full split. |
| * |
| * This reservation amount will be used in the first call to |
| * xfs_bmbt_split() to select an AG with enough space to satisfy the |
| * rest of the operation. |
| */ |
| resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1; |
| |
| do { |
| /* |
| * Set up a transaction to convert the range of extents |
| * from unwritten to real. Do allocations in a loop until |
| * we have covered the range passed in. |
| * |
| * Note that we can't risk to recursing back into the filesystem |
| * here as we might be asked to write out the same inode that we |
| * complete here and might deadlock on the iolock. |
| */ |
| error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, |
| XFS_TRANS_RESERVE, &tp); |
| if (error) |
| return error; |
| |
| xfs_ilock(ip, XFS_ILOCK_EXCL); |
| xfs_trans_ijoin(tp, ip, 0); |
| |
| /* |
| * Modify the unwritten extent state of the buffer. |
| */ |
| nimaps = 1; |
| error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, |
| XFS_BMAPI_CONVERT, resblks, &imap, |
| &nimaps); |
| if (error) |
| goto error_on_bmapi_transaction; |
| |
| /* |
| * Log the updated inode size as we go. We have to be careful |
| * to only log it up to the actual write offset if it is |
| * halfway into a block. |
| */ |
| i_size = XFS_FSB_TO_B(mp, offset_fsb + count_fsb); |
| if (i_size > offset + count) |
| i_size = offset + count; |
| if (update_isize && i_size > i_size_read(inode)) |
| i_size_write(inode, i_size); |
| i_size = xfs_new_eof(ip, i_size); |
| if (i_size) { |
| ip->i_d.di_size = i_size; |
| xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); |
| } |
| |
| error = xfs_trans_commit(tp); |
| xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| if (error) |
| return error; |
| |
| if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip))) |
| return xfs_alert_fsblock_zero(ip, &imap); |
| |
| if ((numblks_fsb = imap.br_blockcount) == 0) { |
| /* |
| * The numblks_fsb value should always get |
| * smaller, otherwise the loop is stuck. |
| */ |
| ASSERT(imap.br_blockcount); |
| break; |
| } |
| offset_fsb += numblks_fsb; |
| count_fsb -= numblks_fsb; |
| } while (count_fsb > 0); |
| |
| return 0; |
| |
| error_on_bmapi_transaction: |
| xfs_trans_cancel(tp); |
| xfs_iunlock(ip, XFS_ILOCK_EXCL); |
| return error; |
| } |
| |
| static inline bool |
| imap_needs_alloc( |
| struct inode *inode, |
| struct xfs_bmbt_irec *imap, |
| int nimaps) |
| { |
| return !nimaps || |
| imap->br_startblock == HOLESTARTBLOCK || |
| imap->br_startblock == DELAYSTARTBLOCK || |
| (IS_DAX(inode) && imap->br_state == XFS_EXT_UNWRITTEN); |
| } |
| |
| static inline bool |
| needs_cow_for_zeroing( |
| struct xfs_bmbt_irec *imap, |
| int nimaps) |
| { |
| return nimaps && |
| imap->br_startblock != HOLESTARTBLOCK && |
| imap->br_state != XFS_EXT_UNWRITTEN; |
| } |
| |
| static int |
| xfs_ilock_for_iomap( |
| struct xfs_inode *ip, |
| unsigned flags, |
| unsigned *lockmode) |
| { |
| unsigned mode = XFS_ILOCK_SHARED; |
| bool is_write = flags & (IOMAP_WRITE | IOMAP_ZERO); |
| |
| /* |
| * 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_cow_inode(ip) && is_write) { |
| /* |
| * FIXME: It could still overwrite on unshared extents and not |
| * need allocation. |
| */ |
| if (flags & IOMAP_NOWAIT) |
| return -EAGAIN; |
| mode = XFS_ILOCK_EXCL; |
| } |
| |
| /* |
| * Extents not yet cached requires exclusive access, don't block. This |
| * is an opencoded xfs_ilock_data_map_shared() call but with |
| * non-blocking behaviour. |
| */ |
| if (!(ip->i_df.if_flags & XFS_IFEXTENTS)) { |
| if (flags & IOMAP_NOWAIT) |
| return -EAGAIN; |
| mode = XFS_ILOCK_EXCL; |
| } |
| |
| relock: |
| if (flags & IOMAP_NOWAIT) { |
| if (!xfs_ilock_nowait(ip, mode)) |
| return -EAGAIN; |
| } else { |
| xfs_ilock(ip, mode); |
| } |
| |
| /* |
| * The reflink iflag could have changed since the earlier unlocked |
| * 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_cow_inode(ip)) { |
| xfs_iunlock(ip, mode); |
| mode = XFS_ILOCK_EXCL; |
| goto relock; |
| } |
| |
| *lockmode = mode; |
| return 0; |
| } |
| |
| static int |
| xfs_file_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; |
| struct xfs_bmbt_irec imap; |
| xfs_fileoff_t offset_fsb, end_fsb; |
| int nimaps = 1, error = 0; |
| bool shared = false; |
| unsigned lockmode; |
| |
| if (XFS_FORCED_SHUTDOWN(mp)) |
| return -EIO; |
| |
| if ((flags & (IOMAP_WRITE | IOMAP_ZERO)) && !(flags & IOMAP_DIRECT) && |
| !IS_DAX(inode) && !xfs_get_extsz_hint(ip)) { |
| /* Reserve delalloc blocks for regular writeback. */ |
| return xfs_file_iomap_begin_delay(inode, offset, length, flags, |
| iomap); |
| } |
| |
| /* |
| * Lock the inode in the manner required for the specified operation and |
| * check for as many conditions that would result in blocking as |
| * possible. This removes most of the non-blocking checks from the |
| * mapping code below. |
| */ |
| error = xfs_ilock_for_iomap(ip, flags, &lockmode); |
| if (error) |
| return error; |
| |
| ASSERT(offset <= mp->m_super->s_maxbytes); |
| if (offset > mp->m_super->s_maxbytes - length) |
| length = mp->m_super->s_maxbytes - offset; |
| offset_fsb = XFS_B_TO_FSBT(mp, offset); |
| end_fsb = XFS_B_TO_FSB(mp, offset + length); |
| |
| error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap, |
| &nimaps, 0); |
| if (error) |
| goto out_unlock; |
| |
| if (flags & IOMAP_REPORT) { |
| /* Trim the mapping to the nearest shared extent boundary. */ |
| error = xfs_reflink_trim_around_shared(ip, &imap, &shared); |
| if (error) |
| goto out_unlock; |
| } |
| |
| /* Non-modifying mapping requested, so we are done */ |
| if (!(flags & (IOMAP_WRITE | IOMAP_ZERO))) |
| goto out_found; |
| |
| /* |
| * 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_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; |
| |
| /* 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; |
| } |
| |
| /* Don't need to allocate over holes when doing zeroing operations. */ |
| if (flags & IOMAP_ZERO) |
| goto out_found; |
| |
| if (!imap_needs_alloc(inode, &imap, nimaps)) |
| goto out_found; |
| |
| /* If nowait is set bail since we are going to make allocations. */ |
| if (flags & IOMAP_NOWAIT) { |
| error = -EAGAIN; |
| goto out_unlock; |
| } |
| |
| /* |
| * We cap the maximum length we map to a sane size 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. |
| */ |
| length = min_t(loff_t, length, 1024 * PAGE_SIZE); |
| |
| /* |
| * xfs_iomap_write_direct() expects the shared lock. It is unlocked on |
| * return. |
| */ |
| if (lockmode == XFS_ILOCK_EXCL) |
| xfs_ilock_demote(ip, lockmode); |
| error = xfs_iomap_write_direct(ip, offset, length, &imap, |
| nimaps); |
| if (error) |
| return error; |
| |
| iomap->flags |= IOMAP_F_NEW; |
| trace_xfs_iomap_alloc(ip, offset, length, XFS_DATA_FORK, &imap); |
| |
| out_finish: |
| return xfs_bmbt_to_iomap(ip, iomap, &imap, shared); |
| |
| out_found: |
| ASSERT(nimaps); |
| xfs_iunlock(ip, lockmode); |
| trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap); |
| goto out_finish; |
| |
| out_unlock: |
| xfs_iunlock(ip, lockmode); |
| return error; |
| } |
| |
| static int |
| xfs_file_iomap_end_delalloc( |
| struct xfs_inode *ip, |
| loff_t offset, |
| loff_t length, |
| ssize_t written, |
| struct iomap *iomap) |
| { |
| struct xfs_mount *mp = ip->i_mount; |
| xfs_fileoff_t start_fsb; |
| xfs_fileoff_t end_fsb; |
| int error = 0; |
| |
| /* |
| * Behave as if the write failed if drop writes is enabled. Set the NEW |
| * flag to force delalloc cleanup. |
| */ |
| if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_DROP_WRITES)) { |
| iomap->flags |= IOMAP_F_NEW; |
| written = 0; |
| } |
| |
| /* |
| * start_fsb refers to the first unused block after a short write. If |
| * nothing was written, round offset down to point at the first block in |
| * the range. |
| */ |
| if (unlikely(!written)) |
| start_fsb = XFS_B_TO_FSBT(mp, offset); |
| else |
| start_fsb = XFS_B_TO_FSB(mp, offset + written); |
| end_fsb = XFS_B_TO_FSB(mp, offset + length); |
| |
| /* |
| * Trim delalloc blocks if they were allocated by this write and we |
| * didn't manage to write the whole range. |
| * |
| * We don't need to care about racing delalloc as we hold i_mutex |
| * across the reserve/allocate/unreserve calls. If there are delalloc |
| * blocks in the range, they are ours. |
| */ |
| if ((iomap->flags & IOMAP_F_NEW) && start_fsb < end_fsb) { |
| truncate_pagecache_range(VFS_I(ip), XFS_FSB_TO_B(mp, start_fsb), |
| XFS_FSB_TO_B(mp, end_fsb) - 1); |
| |
| error = xfs_bmap_punch_delalloc_range(ip, start_fsb, |
| end_fsb - start_fsb); |
| if (error && !XFS_FORCED_SHUTDOWN(mp)) { |
| xfs_alert(mp, "%s: unable to clean up ino %lld", |
| __func__, ip->i_ino); |
| return error; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int |
| xfs_file_iomap_end( |
| struct inode *inode, |
| loff_t offset, |
| loff_t length, |
| ssize_t written, |
| unsigned flags, |
| struct iomap *iomap) |
| { |
| if ((flags & IOMAP_WRITE) && iomap->type == IOMAP_DELALLOC) |
| return xfs_file_iomap_end_delalloc(XFS_I(inode), offset, |
| length, written, iomap); |
| return 0; |
| } |
| |
| const struct iomap_ops xfs_iomap_ops = { |
| .iomap_begin = xfs_file_iomap_begin, |
| .iomap_end = xfs_file_iomap_end, |
| }; |
| |
| 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, |
| 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); |
| struct xfs_bmbt_irec imap; |
| int nimaps = 1, error = 0; |
| unsigned lockmode; |
| |
| if (XFS_FORCED_SHUTDOWN(mp)) |
| return -EIO; |
| |
| lockmode = xfs_ilock_attr_map_shared(ip); |
| |
| /* if there are no attribute fork or extents, return ENOENT */ |
| if (!XFS_IFORK_Q(ip) || !ip->i_d.di_anextents) { |
| error = -ENOENT; |
| goto out_unlock; |
| } |
| |
| ASSERT(ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL); |
| error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap, |
| &nimaps, XFS_BMAPI_ATTRFORK); |
| out_unlock: |
| xfs_iunlock(ip, lockmode); |
| |
| if (error) |
| return error; |
| ASSERT(nimaps); |
| return xfs_bmbt_to_iomap(ip, iomap, &imap, false); |
| } |
| |
| const struct iomap_ops xfs_xattr_iomap_ops = { |
| .iomap_begin = xfs_xattr_iomap_begin, |
| }; |