diff options
Diffstat (limited to 'fs/xfs/xfs_iomap.c')
| -rw-r--r-- | fs/xfs/xfs_iomap.c | 2699 |
1 files changed, 2036 insertions, 663 deletions
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index 6a7096422295..04f39ea15898 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -1,65 +1,205 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) 2000-2006 Silicon Graphics, Inc. + * Copyright (c) 2016-2018 Christoph Hellwig. * All Rights Reserved. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation. - * - * This program is distributed in the hope that it would be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include "xfs.h" #include "xfs_fs.h" -#include "xfs_log.h" -#include "xfs_trans.h" -#include "xfs_sb.h" -#include "xfs_ag.h" -#include "xfs_alloc.h" -#include "xfs_quota.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_bmap_btree.h" -#include "xfs_alloc_btree.h" -#include "xfs_ialloc_btree.h" -#include "xfs_dinode.h" #include "xfs_inode.h" -#include "xfs_inode_item.h" #include "xfs_btree.h" +#include "xfs_bmap_btree.h" #include "xfs_bmap.h" -#include "xfs_rtalloc.h" +#include "xfs_bmap_util.h" +#include "xfs_errortag.h" #include "xfs_error.h" -#include "xfs_itable.h" -#include "xfs_attr.h" -#include "xfs_buf_item.h" +#include "xfs_trans.h" #include "xfs_trans_space.h" -#include "xfs_utils.h" +#include "xfs_inode_item.h" #include "xfs_iomap.h" #include "xfs_trace.h" -#include "xfs_icache.h" +#include "xfs_quota.h" +#include "xfs_rtgroup.h" #include "xfs_dquot_item.h" #include "xfs_dquot.h" +#include "xfs_reflink.h" +#include "xfs_health.h" +#include "xfs_rtbitmap.h" +#include "xfs_icache.h" +#include "xfs_zone_alloc.h" +#define XFS_ALLOC_ALIGN(mp, off) \ + (((off) >> mp->m_allocsize_log) << mp->m_allocsize_log) -#define XFS_WRITEIO_ALIGN(mp,off) (((off) >> mp->m_writeio_log) \ - << mp->m_writeio_log) -#define XFS_WRITE_IMAPS XFS_BMAP_MAX_NMAP - -STATIC int -xfs_iomap_eof_align_last_fsb( - xfs_mount_t *mp, +static int +xfs_alert_fsblock_zero( xfs_inode_t *ip, - xfs_extlen_t extsize, - xfs_fileoff_t *last_fsb) + xfs_bmbt_irec_t *imap) { - xfs_fileoff_t new_last_fsb = 0; - xfs_extlen_t align = 0; - int eof, error; + 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); + xfs_bmap_mark_sick(ip, XFS_DATA_FORK); + return -EFSCORRUPTED; +} + +u64 +xfs_iomap_inode_sequence( + struct xfs_inode *ip, + u16 iomap_flags) +{ + u64 cookie = 0; + + if (iomap_flags & IOMAP_F_XATTR) + return READ_ONCE(ip->i_af.if_seq); + if ((iomap_flags & IOMAP_F_SHARED) && ip->i_cowfp) + cookie = (u64)READ_ONCE(ip->i_cowfp->if_seq) << 32; + return cookie | READ_ONCE(ip->i_df.if_seq); +} + +/* + * Check that the iomap passed to us is still valid for the given offset and + * length. + */ +static bool +xfs_iomap_valid( + struct inode *inode, + const struct iomap *iomap) +{ + struct xfs_inode *ip = XFS_I(inode); + + if (iomap->type == IOMAP_HOLE) + return true; + + if (iomap->validity_cookie != + xfs_iomap_inode_sequence(ip, iomap->flags)) { + trace_xfs_iomap_invalid(ip, iomap); + return false; + } + + XFS_ERRORTAG_DELAY(ip->i_mount, XFS_ERRTAG_WRITE_DELAY_MS); + return true; +} + +const struct iomap_write_ops xfs_iomap_write_ops = { + .iomap_valid = xfs_iomap_valid, +}; + +int +xfs_bmbt_to_iomap( + struct xfs_inode *ip, + struct iomap *iomap, + struct xfs_bmbt_irec *imap, + unsigned int mapping_flags, + u16 iomap_flags, + u64 sequence_cookie) +{ + struct xfs_mount *mp = ip->i_mount; + struct xfs_buftarg *target = xfs_inode_buftarg(ip); + + if (unlikely(!xfs_valid_startblock(ip, imap->br_startblock))) { + xfs_bmap_mark_sick(ip, XFS_DATA_FORK); + 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 { + xfs_daddr_t daddr = xfs_fsb_to_db(ip, imap->br_startblock); + + iomap->addr = BBTOB(daddr); + if (mapping_flags & IOMAP_DAX) + iomap->addr += target->bt_dax_part_off; + + if (imap->br_state == XFS_EXT_UNWRITTEN) + iomap->type = IOMAP_UNWRITTEN; + else + iomap->type = IOMAP_MAPPED; + + /* + * Mark iomaps starting at the first sector of a RTG as merge + * boundary so that each I/O completions is contained to a + * single RTG. + */ + if (XFS_IS_REALTIME_INODE(ip) && xfs_has_rtgroups(mp) && + xfs_rtbno_is_group_start(mp, imap->br_startblock)) + iomap->flags |= IOMAP_F_BOUNDARY; + } + iomap->offset = XFS_FSB_TO_B(mp, imap->br_startoff); + iomap->length = XFS_FSB_TO_B(mp, imap->br_blockcount); + if (mapping_flags & IOMAP_DAX) + iomap->dax_dev = target->bt_daxdev; + else + iomap->bdev = target->bt_bdev; + iomap->flags = iomap_flags; + + /* + * If the inode is dirty for datasync purposes, let iomap know so it + * doesn't elide the IO completion journal flushes on O_DSYNC IO. + */ + if (ip->i_itemp) { + struct xfs_inode_log_item *iip = ip->i_itemp; + + spin_lock(&iip->ili_lock); + if (iip->ili_datasync_seq) + iomap->flags |= IOMAP_F_DIRTY; + spin_unlock(&iip->ili_lock); + } + + iomap->validity_cookie = sequence_cookie; + 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) +{ + struct xfs_buftarg *target = xfs_inode_buftarg(ip); + + 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 = target->bt_bdev; + iomap->dax_dev = target->bt_daxdev; +} + +static inline xfs_fileoff_t +xfs_iomap_end_fsb( + struct xfs_mount *mp, + loff_t offset, + loff_t count) +{ + ASSERT(offset <= mp->m_super->s_maxbytes); + return min(XFS_B_TO_FSB(mp, offset + count), + XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes)); +} + +static xfs_extlen_t +xfs_eof_alignment( + struct xfs_inode *ip) +{ + struct xfs_mount *mp = ip->i_mount; + xfs_extlen_t align = 0; if (!XFS_IS_REALTIME_INODE(ip)) { /* @@ -70,334 +210,182 @@ xfs_iomap_eof_align_last_fsb( * 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)) + if (mp->m_swidth && xfs_has_swalloc(mp)) align = mp->m_swidth; else if (mp->m_dalign) align = mp->m_dalign; - if (align && XFS_ISIZE(ip) >= XFS_FSB_TO_B(mp, align)) - new_last_fsb = roundup_64(*last_fsb, align); + if (align && XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, align)) + align = 0; } + return align; +} + +/* + * Check if last_fsb is outside the last extent, and if so grow it to the next + * stripe unit boundary. + */ +xfs_fileoff_t +xfs_iomap_eof_align_last_fsb( + struct xfs_inode *ip, + xfs_fileoff_t end_fsb) +{ + struct xfs_ifork *ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK); + xfs_extlen_t extsz = xfs_get_extsz_hint(ip); + xfs_extlen_t align = xfs_eof_alignment(ip); + struct xfs_bmbt_irec irec; + struct xfs_iext_cursor icur; + + ASSERT(!xfs_need_iread_extents(ifp)); + /* - * Always round up the allocation request to an extent boundary - * (when file on a real-time subvolume or has di_extsize hint). + * Always round up the allocation request to the extent hint boundary. */ - if (extsize) { - if (new_last_fsb) - align = roundup_64(new_last_fsb, extsize); + if (extsz) { + if (align) + align = roundup_64(align, extsz); else - align = extsize; - new_last_fsb = roundup_64(*last_fsb, align); + align = extsz; } - if (new_last_fsb) { - error = xfs_bmap_eof(ip, new_last_fsb, XFS_DATA_FORK, &eof); - if (error) - return error; - if (eof) - *last_fsb = new_last_fsb; + if (align) { + xfs_fileoff_t aligned_end_fsb = roundup_64(end_fsb, align); + + xfs_iext_last(ifp, &icur); + if (!xfs_iext_get_extent(ifp, &icur, &irec) || + aligned_end_fsb >= irec.br_startoff + irec.br_blockcount) + return aligned_end_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\n", - (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; + return end_fsb; } int xfs_iomap_write_direct( - xfs_inode_t *ip, - xfs_off_t offset, - size_t count, - xfs_bmbt_irec_t *imap, - int nmaps) + struct xfs_inode *ip, + xfs_fileoff_t offset_fsb, + xfs_fileoff_t count_fsb, + unsigned int flags, + struct xfs_bmbt_irec *imap, + u64 *seq) { - xfs_mount_t *mp = ip->i_mount; - xfs_fileoff_t offset_fsb; - xfs_fileoff_t last_fsb; - xfs_filblks_t count_fsb, resaligned; - xfs_fsblock_t firstfsb; - xfs_extlen_t extsz, temp; - int nimaps; - int bmapi_flag; - int quota_flag; - int rt; - xfs_trans_t *tp; - xfs_bmap_free_t free_list; - uint qblocks, resblks, resrtextents; - int committed; - int error; - - error = xfs_qm_dqattach(ip, 0); - if (error) - return XFS_ERROR(error); + struct xfs_mount *mp = ip->i_mount; + struct xfs_trans *tp; + xfs_filblks_t resaligned; + int nimaps; + unsigned int dblocks, rblocks; + bool force = false; + int error; + int bmapi_flags = XFS_BMAPI_PREALLOC; + int nr_exts = XFS_IEXT_ADD_NOSPLIT_CNT; - rt = XFS_IS_REALTIME_INODE(ip); - extsz = xfs_get_extsz_hint(ip); - - 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)) { - error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb); - if (error) - return XFS_ERROR(error); - } 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 = count_fsb; - if (unlikely(extsz)) { - if ((temp = do_mod(offset_fsb, extsz))) - resaligned += temp; - if ((temp = do_mod(resaligned, extsz))) - resaligned += extsz - temp; - } - - 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; + resaligned = xfs_aligned_fsb_count(offset_fsb, count_fsb, + xfs_get_extsz_hint(ip)); + if (unlikely(XFS_IS_REALTIME_INODE(ip))) { + dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0); + rblocks = resaligned; } else { - resrtextents = 0; - resblks = qblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned); - quota_flag = XFS_QMOPT_RES_REGBLKS; + dblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned); + rblocks = 0; } + error = xfs_qm_dqattach(ip); + if (error) + return error; + /* - * Allocate and setup the transaction - */ - tp = xfs_trans_alloc(mp, XFS_TRANS_DIOSTRAT); - error = xfs_trans_reserve(tp, resblks, - XFS_WRITE_LOG_RES(mp), resrtextents, - XFS_TRANS_PERM_LOG_RES, - XFS_WRITE_LOG_COUNT); - /* - * Check for running out of space, note: need lock to return + * 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 (error) { - xfs_trans_cancel(tp, 0); - return XFS_ERROR(error); + if (flags & IOMAP_DAX) { + bmapi_flags = XFS_BMAPI_CONVERT | XFS_BMAPI_ZERO; + if (imap->br_state == XFS_EXT_UNWRITTEN) { + force = true; + nr_exts = XFS_IEXT_WRITE_UNWRITTEN_CNT; + dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1; + } } - xfs_ilock(ip, XFS_ILOCK_EXCL); + error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write, dblocks, + rblocks, force, &tp); + if (error) + return error; - error = xfs_trans_reserve_quota_nblks(tp, ip, qblocks, 0, quota_flag); + error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK, nr_exts); if (error) goto out_trans_cancel; - xfs_trans_ijoin(tp, ip, 0); - - bmapi_flag = 0; - if (offset < XFS_ISIZE(ip) || extsz) - bmapi_flag |= XFS_BMAPI_PREALLOC; - /* * From this point onwards we overwrite the imap pointer that the * caller gave to us. */ - xfs_bmap_init(&free_list, &firstfsb); nimaps = 1; - error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, bmapi_flag, - &firstfsb, 0, imap, &nimaps, &free_list); + error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, bmapi_flags, 0, + imap, &nimaps); if (error) - goto out_bmap_cancel; + goto out_trans_cancel; /* * Complete the transaction */ - error = xfs_bmap_finish(&tp, &free_list, &committed); - if (error) - goto out_bmap_cancel; - error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); + 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 = XFS_ERROR(ENOSPC); - goto out_unlock; - } - - if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip))) + if (unlikely(!xfs_valid_startblock(ip, imap->br_startblock))) { + xfs_bmap_mark_sick(ip, XFS_DATA_FORK); error = xfs_alert_fsblock_zero(ip, imap); + } out_unlock: + *seq = xfs_iomap_inode_sequence(ip, 0); xfs_iunlock(ip, XFS_ILOCK_EXCL); return error; -out_bmap_cancel: - xfs_bmap_cancel(&free_list); - xfs_trans_unreserve_quota_nblks(tp, ip, (long)qblocks, 0, quota_flag); out_trans_cancel: - xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT); + xfs_trans_cancel(tp); goto out_unlock; } -/* - * If the caller is doing a write at the end of the file, then extend the - * allocation out to the file system's write iosize. We clean up any extra - * space left over when the file is closed in xfs_inactive(). - * - * If we find we already have delalloc preallocation beyond EOF, don't do more - * preallocation as it it not needed. - */ -STATIC int -xfs_iomap_eof_want_preallocate( - xfs_mount_t *mp, - xfs_inode_t *ip, - xfs_off_t offset, - size_t count, - xfs_bmbt_irec_t *imap, - int nimaps, - int *prealloc) -{ - xfs_fileoff_t start_fsb; - xfs_filblks_t count_fsb; - xfs_fsblock_t firstblock; - int n, error, imaps; - int found_delalloc = 0; - - *prealloc = 0; - if (offset + count <= XFS_ISIZE(ip)) - return 0; - - /* - * If the file is smaller than the minimum prealloc and we are using - * dynamic preallocation, don't do any preallocation at all as it is - * likely this is the only write to the file that is going to be done. - */ - if (!(mp->m_flags & XFS_MOUNT_DFLT_IOSIZE) && - XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_writeio_blocks)) - return 0; - - /* - * If there are any real blocks past eof, then don't - * do any speculative allocation. - */ - start_fsb = XFS_B_TO_FSBT(mp, ((xfs_ufsize_t)(offset + count - 1))); - count_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes); - while (count_fsb > 0) { - imaps = nimaps; - firstblock = NULLFSBLOCK; - error = xfs_bmapi_read(ip, start_fsb, count_fsb, imap, &imaps, - 0); - if (error) - return error; - for (n = 0; n < imaps; n++) { - if ((imap[n].br_startblock != HOLESTARTBLOCK) && - (imap[n].br_startblock != DELAYSTARTBLOCK)) - return 0; - start_fsb += imap[n].br_blockcount; - count_fsb -= imap[n].br_blockcount; - - if (imap[n].br_startblock == DELAYSTARTBLOCK) - found_delalloc = 1; - } - } - if (!found_delalloc) - *prealloc = 1; - return 0; -} - -/* - * 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 preceeding 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. - */ -STATIC xfs_fsblock_t -xfs_iomap_eof_prealloc_initial_size( - struct xfs_mount *mp, - struct xfs_inode *ip, - xfs_off_t offset, - xfs_bmbt_irec_t *imap, - int nimaps) -{ - xfs_fileoff_t start_fsb; - int imaps = 1; - int error; - - ASSERT(nimaps >= imaps); - - /* if we are using a specific prealloc size, return now */ - if (mp->m_flags & XFS_MOUNT_DFLT_IOSIZE) - return 0; - - /* If the file is small, then use the minimum prealloc */ - if (XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_dalign)) - return 0; - - /* - * As we write multiple pages, the offset will always align to the - * start of a page and hence point to a hole at EOF. i.e. if the size is - * 4096 bytes, we only have one block at FSB 0, but XFS_B_TO_FSB(4096) - * will return FSB 1. Hence if there are blocks in the file, we want to - * point to the block prior to the EOF block and not the hole that maps - * directly at @offset. - */ - start_fsb = XFS_B_TO_FSB(mp, offset); - if (start_fsb) - start_fsb--; - error = xfs_bmapi_read(ip, start_fsb, 1, imap, &imaps, XFS_BMAPI_ENTIRE); - if (error) - return 0; - - ASSERT(imaps == 1); - if (imap[0].br_startblock == HOLESTARTBLOCK) - return 0; - if (imap[0].br_blockcount <= (MAXEXTLEN >> 1)) - return imap[0].br_blockcount << 1; - return XFS_B_TO_FSB(mp, offset); -} - STATIC bool xfs_quota_need_throttle( - struct xfs_inode *ip, - int type, - xfs_fsblock_t alloc_blocks) + struct xfs_inode *ip, + xfs_dqtype_t type, + xfs_fsblock_t alloc_blocks) { - struct xfs_dquot *dq = xfs_inode_dquot(ip, type); + struct xfs_dquot *dq = xfs_inode_dquot(ip, type); + struct xfs_dquot_res *res; + struct xfs_dquot_pre *pre; if (!dq || !xfs_this_quota_on(ip->i_mount, type)) return false; + if (XFS_IS_REALTIME_INODE(ip)) { + res = &dq->q_rtb; + pre = &dq->q_rtb_prealloc; + } else { + res = &dq->q_blk; + pre = &dq->q_blk_prealloc; + } + /* no hi watermark, no throttle */ - if (!dq->q_prealloc_hi_wmark) + if (!pre->q_prealloc_hi_wmark) return false; /* under the lo watermark, no throttle */ - if (dq->q_res_bcount + alloc_blocks < dq->q_prealloc_lo_wmark) + if (res->reserved + alloc_blocks < pre->q_prealloc_lo_wmark) return false; return true; @@ -405,30 +393,48 @@ xfs_quota_need_throttle( STATIC void xfs_quota_calc_throttle( - struct xfs_inode *ip, - int type, - xfs_fsblock_t *qblocks, - int *qshift) + struct xfs_inode *ip, + xfs_dqtype_t 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); + struct xfs_dquot *dq = xfs_inode_dquot(ip, type); + struct xfs_dquot_res *res; + struct xfs_dquot_pre *pre; + int64_t freesp; + int shift = 0; + + if (!dq) { + res = NULL; + pre = NULL; + } else if (XFS_IS_REALTIME_INODE(ip)) { + res = &dq->q_rtb; + pre = &dq->q_rtb_prealloc; + } else { + res = &dq->q_blk; + pre = &dq->q_blk_prealloc; + } - /* over hi wmark, squash the prealloc completely */ - if (dq->q_res_bcount >= dq->q_prealloc_hi_wmark) { + /* no dq, or over hi wmark, squash the prealloc completely */ + if (!res || res->reserved >= pre->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]) { + freesp = pre->q_prealloc_hi_wmark - res->reserved; + if (freesp < pre->q_low_space[XFS_QLOWSP_5_PCNT]) { shift = 2; - if (freesp < dq->q_low_space[XFS_QLOWSP_3_PCNT]) + if (freesp < pre->q_low_space[XFS_QLOWSP_3_PCNT]) shift += 2; - if (freesp < dq->q_low_space[XFS_QLOWSP_1_PCNT]) + if (freesp < pre->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; @@ -436,66 +442,133 @@ xfs_quota_calc_throttle( } } +static int64_t +xfs_iomap_freesp( + struct xfs_mount *mp, + unsigned int idx, + uint64_t low_space[XFS_LOWSP_MAX], + int *shift) +{ + int64_t freesp; + + freesp = xfs_estimate_freecounter(mp, idx); + if (freesp < low_space[XFS_LOWSP_5_PCNT]) { + *shift = 2; + if (freesp < low_space[XFS_LOWSP_4_PCNT]) + (*shift)++; + if (freesp < low_space[XFS_LOWSP_3_PCNT]) + (*shift)++; + if (freesp < low_space[XFS_LOWSP_2_PCNT]) + (*shift)++; + if (freesp < low_space[XFS_LOWSP_1_PCNT]) + (*shift)++; + } + return freesp; +} + /* * 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 + * 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. + * filesystem is to being full, the smaller the maximum preallocation. */ STATIC xfs_fsblock_t xfs_iomap_prealloc_size( - struct xfs_mount *mp, struct xfs_inode *ip, - xfs_off_t offset, - struct xfs_bmbt_irec *imap, - int nimaps) + int whichfork, + loff_t offset, + loff_t count, + struct xfs_iext_cursor *icur) { - xfs_fsblock_t alloc_blocks = 0; - int shift = 0; + struct xfs_iext_cursor ncur = *icur; + struct xfs_bmbt_irec prev, got; + 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); int64_t freesp; xfs_fsblock_t qblocks; + xfs_fsblock_t alloc_blocks = 0; + xfs_extlen_t plen; + int shift = 0; int qshift = 0; - alloc_blocks = xfs_iomap_eof_prealloc_initial_size(mp, ip, offset, - imap, nimaps); - if (!alloc_blocks) - goto check_writeio; + /* + * 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. + */ + if (XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_allocsize_blocks)) + return 0; + + /* + * Use the minimum preallocation size for small files or if we are + * writing right after a hole. + */ + if (XFS_ISIZE(ip) < XFS_FSB_TO_B(mp, mp->m_dalign) || + !xfs_iext_prev_extent(ifp, &ncur, &prev) || + prev.br_startoff + prev.br_blockcount < offset_fsb) + return mp->m_allocsize_blocks; + + /* + * Take the size of the preceding data extents as the basis for the + * preallocation size. Note that we don't care if the previous extents + * are written or not. + */ + plen = prev.br_blockcount; + while (xfs_iext_prev_extent(ifp, &ncur, &got)) { + if (plen > XFS_MAX_BMBT_EXTLEN / 2 || + isnullstartblock(got.br_startblock) || + got.br_startoff + got.br_blockcount != prev.br_startoff || + got.br_startblock + got.br_blockcount != prev.br_startblock) + break; + plen += got.br_blockcount; + prev = got; + } + + /* + * If the size of the extents 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 + * XFS_BMBT_MAX_EXTLEN rather than falling short due to things like stripe + * unit/width alignment of real extents. + */ + alloc_blocks = plen * 2; + if (alloc_blocks > XFS_MAX_BMBT_EXTLEN) + alloc_blocks = XFS_B_TO_FSB(mp, offset); 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. + * XFS_BMBT_MAX_EXTLEN 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 XFS_BMBT_MAX_EXTLEN. */ - alloc_blocks = XFS_FILEOFF_MIN(roundup_pow_of_two(MAXEXTLEN), + alloc_blocks = XFS_FILEOFF_MIN(roundup_pow_of_two(XFS_MAX_BMBT_EXTLEN), alloc_blocks); - xfs_icsb_sync_counters(mp, XFS_ICSB_LAZY_COUNT); - freesp = mp->m_sb.sb_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++; - } + if (unlikely(XFS_IS_REALTIME_INODE(ip))) + freesp = xfs_rtbxlen_to_blen(mp, + xfs_iomap_freesp(mp, XC_FREE_RTEXTENTS, + mp->m_low_rtexts, &shift)); + else + freesp = xfs_iomap_freesp(mp, XC_FREE_BLOCKS, mp->m_low_space, + &shift); /* - * Check each quota to cap the prealloc size and provide a shift - * value to throttle with. + * 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); - if (xfs_quota_need_throttle(ip, XFS_DQ_GROUP, alloc_blocks)) - xfs_quota_calc_throttle(ip, XFS_DQ_GROUP, &qblocks, &qshift); - if (xfs_quota_need_throttle(ip, XFS_DQ_PROJ, alloc_blocks)) - xfs_quota_calc_throttle(ip, XFS_DQ_PROJ, &qblocks, &qshift); + if (xfs_quota_need_throttle(ip, XFS_DQTYPE_USER, alloc_blocks)) + xfs_quota_calc_throttle(ip, XFS_DQTYPE_USER, &qblocks, &qshift, + &freesp); + if (xfs_quota_need_throttle(ip, XFS_DQTYPE_GROUP, alloc_blocks)) + xfs_quota_calc_throttle(ip, XFS_DQTYPE_GROUP, &qblocks, &qshift, + &freesp); + if (xfs_quota_need_throttle(ip, XFS_DQTYPE_PROJ, alloc_blocks)) + xfs_quota_calc_throttle(ip, XFS_DQTYPE_PROJ, &qblocks, &qshift, + &freesp); /* * The final prealloc size is set to the minimum of free space available @@ -504,8 +577,8 @@ xfs_iomap_prealloc_size( * 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); + alloc_blocks = min(alloc_blocks, qblocks); + shift = max(shift, qshift); if (shift) alloc_blocks >>= shift; @@ -515,422 +588,1722 @@ xfs_iomap_prealloc_size( */ if (alloc_blocks) alloc_blocks = rounddown_pow_of_two(alloc_blocks); - if (alloc_blocks > MAXEXTLEN) - alloc_blocks = MAXEXTLEN; + if (alloc_blocks > XFS_MAX_BMBT_EXTLEN) + alloc_blocks = XFS_MAX_BMBT_EXTLEN; /* * 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. + * lowspace thresholds are smaller than XFS_BMBT_MAX_EXTLEN. */ while (alloc_blocks && alloc_blocks >= freesp) alloc_blocks >>= 4; - -check_writeio: - if (alloc_blocks < mp->m_writeio_blocks) - alloc_blocks = mp->m_writeio_blocks; - + if (alloc_blocks < mp->m_allocsize_blocks) + alloc_blocks = mp->m_allocsize_blocks; trace_xfs_iomap_prealloc_size(ip, alloc_blocks, shift, - mp->m_writeio_blocks); - + mp->m_allocsize_blocks); return alloc_blocks; } int -xfs_iomap_write_delay( +xfs_iomap_write_unwritten( xfs_inode_t *ip, xfs_off_t offset, - size_t count, - xfs_bmbt_irec_t *ret_imap) + xfs_off_t count, + bool update_isize) { xfs_mount_t *mp = ip->i_mount; xfs_fileoff_t offset_fsb; - xfs_fileoff_t last_fsb; - xfs_off_t aligned_offset; - xfs_fileoff_t ioalign; - xfs_extlen_t extsz; + xfs_filblks_t count_fsb; + xfs_filblks_t numblks_fsb; int nimaps; - xfs_bmbt_irec_t imap[XFS_WRITE_IMAPS]; - int prealloc; + xfs_trans_t *tp; + xfs_bmbt_irec_t imap; + struct inode *inode = VFS_I(ip); + xfs_fsize_t i_size; + uint resblks; int error; - ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); + 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); /* - * Make sure that the dquots are there. This doesn't hold - * the ilock across a disk read. + * 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. */ - error = xfs_qm_dqattach_locked(ip, 0); + resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1; + + /* Attach dquots so that bmbt splits are accounted correctly. */ + error = xfs_qm_dqattach(ip); if (error) - return XFS_ERROR(error); + return error; - extsz = xfs_get_extsz_hint(ip); - offset_fsb = XFS_B_TO_FSBT(mp, offset); + 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_inode(ip, &M_RES(mp)->tr_write, resblks, + 0, true, &tp); + if (error) + return error; + + error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK, + XFS_IEXT_WRITE_UNWRITTEN_CNT); + if (error) + goto error_on_bmapi_transaction; + + /* + * 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_disk_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 (unlikely(!xfs_valid_startblock(ip, imap.br_startblock))) { + xfs_bmap_mark_sick(ip, XFS_DATA_FORK); + 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, + unsigned flags, + struct xfs_bmbt_irec *imap, + int nimaps) +{ + /* don't allocate blocks when just zeroing */ + if (flags & IOMAP_ZERO) + return false; + if (!nimaps || + imap->br_startblock == HOLESTARTBLOCK || + imap->br_startblock == DELAYSTARTBLOCK) + return true; + /* we convert unwritten extents before copying the data for DAX */ + if ((flags & IOMAP_DAX) && imap->br_state == XFS_EXT_UNWRITTEN) + return true; + return false; +} + +static inline bool +imap_needs_cow( + struct xfs_inode *ip, + unsigned int flags, + struct xfs_bmbt_irec *imap, + int nimaps) +{ + if (!xfs_is_cow_inode(ip)) + return false; + + /* when zeroing we don't have to COW holes or unwritten extents */ + if (flags & (IOMAP_UNSHARE | IOMAP_ZERO)) { + if (!nimaps || + imap->br_startblock == HOLESTARTBLOCK || + imap->br_state == XFS_EXT_UNWRITTEN) + return false; + } + + return true; +} + +/* + * Extents not yet cached requires exclusive access, don't block for + * IOMAP_NOWAIT. + * + * This is basically an opencoded xfs_ilock_data_map_shared() call, but with + * support for IOMAP_NOWAIT. + */ +static int +xfs_ilock_for_iomap( + struct xfs_inode *ip, + unsigned flags, + unsigned *lockmode) +{ + if (flags & IOMAP_NOWAIT) { + if (xfs_need_iread_extents(&ip->i_df)) + return -EAGAIN; + if (!xfs_ilock_nowait(ip, *lockmode)) + return -EAGAIN; + } else { + if (xfs_need_iread_extents(&ip->i_df)) + *lockmode = XFS_ILOCK_EXCL; + xfs_ilock(ip, *lockmode); + } + + return 0; +} + +/* + * Check that the imap we are going to return to the caller spans the entire + * range that the caller requested for the IO. + */ +static bool +imap_spans_range( + struct xfs_bmbt_irec *imap, + xfs_fileoff_t offset_fsb, + xfs_fileoff_t end_fsb) +{ + if (imap->br_startoff > offset_fsb) + return false; + if (imap->br_startoff + imap->br_blockcount < end_fsb) + return false; + return true; +} + +static bool +xfs_bmap_hw_atomic_write_possible( + struct xfs_inode *ip, + struct xfs_bmbt_irec *imap, + xfs_fileoff_t offset_fsb, + xfs_fileoff_t end_fsb) +{ + struct xfs_mount *mp = ip->i_mount; + xfs_fsize_t len = XFS_FSB_TO_B(mp, end_fsb - offset_fsb); + + /* + * atomic writes are required to be naturally aligned for disk blocks, + * which ensures that we adhere to block layer rules that we won't + * straddle any boundary or violate write alignment requirement. + */ + if (!IS_ALIGNED(imap->br_startblock, imap->br_blockcount)) + return false; + + /* + * Spanning multiple extents would mean that multiple BIOs would be + * issued, and so would lose atomicity required for REQ_ATOMIC-based + * atomics. + */ + if (!imap_spans_range(imap, offset_fsb, end_fsb)) + return false; + + /* + * The ->iomap_begin caller should ensure this, but check anyway. + */ + return len <= xfs_inode_buftarg(ip)->bt_awu_max; +} + +static int +xfs_direct_write_iomap_begin( + struct inode *inode, + loff_t offset, + loff_t length, + unsigned flags, + struct iomap *iomap, + struct iomap *srcmap) +{ + struct xfs_inode *ip = XFS_I(inode); + struct xfs_mount *mp = ip->i_mount; + struct xfs_bmbt_irec imap, cmap; + xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); + xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, length); + xfs_fileoff_t orig_end_fsb = end_fsb; + int nimaps = 1, error = 0; + bool shared = false; + u16 iomap_flags = 0; + bool needs_alloc; + unsigned int lockmode; + u64 seq; + + ASSERT(flags & (IOMAP_WRITE | IOMAP_ZERO)); + + if (xfs_is_shutdown(mp)) + return -EIO; + + /* + * Writes that span EOF might trigger an IO size update on completion, + * so consider them to be dirty for the purposes of O_DSYNC even if + * there is no other metadata changes pending or have been made here. + */ + if (offset + length > i_size_read(inode)) + iomap_flags |= IOMAP_F_DIRTY; + + /* HW-offload atomics are always used in this path */ + if (flags & IOMAP_ATOMIC) + iomap_flags |= IOMAP_F_ATOMIC_BIO; + + /* + * 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)) + lockmode = XFS_ILOCK_EXCL; + else + lockmode = XFS_ILOCK_SHARED; + +relock: + error = xfs_ilock_for_iomap(ip, flags, &lockmode); + if (error) + return error; + + /* + * The reflink iflag could have changed since the earlier unlocked + * check, check if it again and relock if needed. + */ + if (xfs_is_cow_inode(ip) && lockmode == XFS_ILOCK_SHARED) { + xfs_iunlock(ip, lockmode); + lockmode = XFS_ILOCK_EXCL; + goto relock; + } + + error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap, + &nimaps, 0); + if (error) + goto out_unlock; + + if (imap_needs_cow(ip, flags, &imap, nimaps)) { + error = -EAGAIN; + if (flags & IOMAP_NOWAIT) + goto out_unlock; + + /* may drop and re-acquire the ilock */ + error = xfs_reflink_allocate_cow(ip, &imap, &cmap, &shared, + &lockmode, + (flags & IOMAP_DIRECT) || IS_DAX(inode)); + if (error) + goto out_unlock; + if (shared) { + if ((flags & IOMAP_ATOMIC) && + !xfs_bmap_hw_atomic_write_possible(ip, &cmap, + offset_fsb, end_fsb)) { + error = -ENOPROTOOPT; + goto out_unlock; + } + goto out_found_cow; + } + end_fsb = imap.br_startoff + imap.br_blockcount; + length = XFS_FSB_TO_B(mp, end_fsb) - offset; + } + + needs_alloc = imap_needs_alloc(inode, flags, &imap, nimaps); + + if (flags & IOMAP_ATOMIC) { + error = -ENOPROTOOPT; + /* + * If we allocate less than what is required for the write + * then we may end up with multiple extents, which means that + * REQ_ATOMIC-based cannot be used, so avoid this possibility. + */ + if (needs_alloc && orig_end_fsb - offset_fsb > 1) + goto out_unlock; + + if (!xfs_bmap_hw_atomic_write_possible(ip, &imap, offset_fsb, + orig_end_fsb)) + goto out_unlock; + } + + if (needs_alloc) + goto allocate_blocks; + + /* + * NOWAIT and OVERWRITE I/O needs to span the entire requested I/O with + * a single map so that we avoid partial IO failures due to the rest of + * the I/O range not covered by this map triggering an EAGAIN condition + * when it is subsequently mapped and aborting the I/O. + */ + if (flags & (IOMAP_NOWAIT | IOMAP_OVERWRITE_ONLY)) { + error = -EAGAIN; + if (!imap_spans_range(&imap, offset_fsb, end_fsb)) + goto out_unlock; + } + + /* + * For overwrite only I/O, we cannot convert unwritten extents without + * requiring sub-block zeroing. This can only be done under an + * exclusive IOLOCK, hence return -EAGAIN if this is not a written + * extent to tell the caller to try again. + */ + if (flags & IOMAP_OVERWRITE_ONLY) { + error = -EAGAIN; + if (imap.br_state != XFS_EXT_NORM && + ((offset | length) & mp->m_blockmask)) + goto out_unlock; + } - error = xfs_iomap_eof_want_preallocate(mp, ip, offset, count, - imap, XFS_WRITE_IMAPS, &prealloc); + seq = xfs_iomap_inode_sequence(ip, iomap_flags); + xfs_iunlock(ip, lockmode); + trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap); + return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, iomap_flags, seq); + +allocate_blocks: + error = -EAGAIN; + if (flags & (IOMAP_NOWAIT | IOMAP_OVERWRITE_ONLY)) + 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); + end_fsb = xfs_iomap_end_fsb(mp, offset, length); + + if (offset + length > XFS_ISIZE(ip)) + end_fsb = xfs_iomap_eof_align_last_fsb(ip, end_fsb); + else if (nimaps && imap.br_startblock == HOLESTARTBLOCK) + end_fsb = min(end_fsb, imap.br_startoff + imap.br_blockcount); + xfs_iunlock(ip, lockmode); + + error = xfs_iomap_write_direct(ip, offset_fsb, end_fsb - offset_fsb, + flags, &imap, &seq); if (error) return error; + trace_xfs_iomap_alloc(ip, offset, length, XFS_DATA_FORK, &imap); + return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, + iomap_flags | IOMAP_F_NEW, seq); + +out_found_cow: + length = XFS_FSB_TO_B(mp, cmap.br_startoff + cmap.br_blockcount); + trace_xfs_iomap_found(ip, offset, length - offset, XFS_COW_FORK, &cmap); + if (imap.br_startblock != HOLESTARTBLOCK) { + seq = xfs_iomap_inode_sequence(ip, 0); + error = xfs_bmbt_to_iomap(ip, srcmap, &imap, flags, 0, seq); + if (error) + goto out_unlock; + } + seq = xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED); + xfs_iunlock(ip, lockmode); + return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, IOMAP_F_SHARED, seq); + +out_unlock: + if (lockmode) + xfs_iunlock(ip, lockmode); + return error; +} + +const struct iomap_ops xfs_direct_write_iomap_ops = { + .iomap_begin = xfs_direct_write_iomap_begin, +}; + +#ifdef CONFIG_XFS_RT +/* + * This is really simple. The space has already been reserved before taking the + * IOLOCK, the actual block allocation is done just before submitting the bio + * and only recorded in the extent map on I/O completion. + */ +static int +xfs_zoned_direct_write_iomap_begin( + struct inode *inode, + loff_t offset, + loff_t length, + unsigned flags, + struct iomap *iomap, + struct iomap *srcmap) +{ + struct xfs_inode *ip = XFS_I(inode); + int error; + + ASSERT(!(flags & IOMAP_OVERWRITE_ONLY)); + + /* + * Needs to be pushed down into the allocator so that only writes into + * a single zone can be supported. + */ + if (flags & IOMAP_NOWAIT) + return -EAGAIN; + + /* + * Ensure the extent list is in memory in so that we don't have to do + * read it from the I/O completion handler. + */ + if (xfs_need_iread_extents(&ip->i_df)) { + xfs_ilock(ip, XFS_ILOCK_EXCL); + error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + if (error) + return error; + } + + iomap->type = IOMAP_MAPPED; + iomap->flags = IOMAP_F_DIRTY; + iomap->bdev = ip->i_mount->m_rtdev_targp->bt_bdev; + iomap->offset = offset; + iomap->length = length; + iomap->flags = IOMAP_F_ANON_WRITE; + return 0; +} + +const struct iomap_ops xfs_zoned_direct_write_iomap_ops = { + .iomap_begin = xfs_zoned_direct_write_iomap_begin, +}; +#endif /* CONFIG_XFS_RT */ + +#ifdef DEBUG +static void +xfs_check_atomic_cow_conversion( + struct xfs_inode *ip, + xfs_fileoff_t offset_fsb, + xfs_filblks_t count_fsb, + const struct xfs_bmbt_irec *cmap) +{ + struct xfs_iext_cursor icur; + struct xfs_bmbt_irec cmap2 = { }; + + if (xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &cmap2)) + xfs_trim_extent(&cmap2, offset_fsb, count_fsb); + + ASSERT(cmap2.br_startoff == cmap->br_startoff); + ASSERT(cmap2.br_blockcount == cmap->br_blockcount); + ASSERT(cmap2.br_startblock == cmap->br_startblock); + ASSERT(cmap2.br_state == cmap->br_state); +} +#else +# define xfs_check_atomic_cow_conversion(...) ((void)0) +#endif + +static int +xfs_atomic_write_cow_iomap_begin( + struct inode *inode, + loff_t offset, + loff_t length, + unsigned flags, + struct iomap *iomap, + struct iomap *srcmap) +{ + struct xfs_inode *ip = XFS_I(inode); + struct xfs_mount *mp = ip->i_mount; + const xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); + const xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + length); + const xfs_filblks_t count_fsb = end_fsb - offset_fsb; + xfs_filblks_t hole_count_fsb; + int nmaps = 1; + xfs_filblks_t resaligned; + struct xfs_bmbt_irec cmap; + struct xfs_iext_cursor icur; + struct xfs_trans *tp; + unsigned int dblocks = 0, rblocks = 0; + int error; + u64 seq; + + ASSERT(flags & IOMAP_WRITE); + ASSERT(flags & IOMAP_DIRECT); + + if (xfs_is_shutdown(mp)) + return -EIO; + + if (!xfs_can_sw_atomic_write(mp)) { + ASSERT(xfs_can_sw_atomic_write(mp)); + return -EINVAL; + } + + /* blocks are always allocated in this path */ + if (flags & IOMAP_NOWAIT) + return -EAGAIN; + + trace_xfs_iomap_atomic_write_cow(ip, offset, length); retry: - if (prealloc) { - xfs_fsblock_t alloc_blocks; + xfs_ilock(ip, XFS_ILOCK_EXCL); - alloc_blocks = xfs_iomap_prealloc_size(mp, ip, offset, imap, - XFS_WRITE_IMAPS); + if (!ip->i_cowfp) { + ASSERT(!xfs_is_reflink_inode(ip)); + xfs_ifork_init_cow(ip); + } + + if (!xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &cmap)) + cmap.br_startoff = end_fsb; + if (cmap.br_startoff <= offset_fsb) { + if (isnullstartblock(cmap.br_startblock)) + goto convert_delay; + + /* + * cmap could extend outside the write range due to previous + * speculative preallocations. We must trim cmap to the write + * range because the cow fork treats written mappings to mean + * "write in progress". + */ + xfs_trim_extent(&cmap, offset_fsb, count_fsb); + goto found; + } - aligned_offset = XFS_WRITEIO_ALIGN(mp, (offset + count - 1)); - ioalign = XFS_B_TO_FSBT(mp, aligned_offset); - last_fsb = ioalign + alloc_blocks; + hole_count_fsb = cmap.br_startoff - offset_fsb; + + resaligned = xfs_aligned_fsb_count(offset_fsb, hole_count_fsb, + xfs_get_cowextsz_hint(ip)); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + + if (XFS_IS_REALTIME_INODE(ip)) { + dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0); + rblocks = resaligned; } else { - last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count))); + dblocks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned); + rblocks = 0; } - if (prealloc || extsz) { - error = xfs_iomap_eof_align_last_fsb(mp, ip, extsz, &last_fsb); + error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write, dblocks, + rblocks, false, &tp); + if (error) + return error; + + /* extent layout could have changed since the unlock, so check again */ + if (!xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &cmap)) + cmap.br_startoff = end_fsb; + if (cmap.br_startoff <= offset_fsb) { + xfs_trans_cancel(tp); + if (isnullstartblock(cmap.br_startblock)) + goto convert_delay; + xfs_trim_extent(&cmap, offset_fsb, count_fsb); + goto found; + } + + /* + * Allocate the entire reservation as unwritten blocks. + * + * Use XFS_BMAPI_EXTSZALIGN to hint at aligning new extents according to + * extszhint, such that there will be a greater chance that future + * atomic writes to that same range will be aligned (and don't require + * this COW-based method). + */ + error = xfs_bmapi_write(tp, ip, offset_fsb, hole_count_fsb, + XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC | + XFS_BMAPI_EXTSZALIGN, 0, &cmap, &nmaps); + if (error) { + xfs_trans_cancel(tp); + goto out_unlock; + } + + xfs_inode_set_cowblocks_tag(ip); + error = xfs_trans_commit(tp); + if (error) + goto out_unlock; + + /* + * cmap could map more blocks than the range we passed into bmapi_write + * because of EXTSZALIGN or adjacent pre-existing unwritten mappings + * that were merged. Trim cmap to the original write range so that we + * don't convert more than we were asked to do for this write. + */ + xfs_trim_extent(&cmap, offset_fsb, count_fsb); + +found: + if (cmap.br_state != XFS_EXT_NORM) { + error = xfs_reflink_convert_cow_locked(ip, cmap.br_startoff, + cmap.br_blockcount); if (error) - return error; + goto out_unlock; + cmap.br_state = XFS_EXT_NORM; + xfs_check_atomic_cow_conversion(ip, offset_fsb, count_fsb, + &cmap); } + trace_xfs_iomap_found(ip, offset, length, XFS_COW_FORK, &cmap); + seq = xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, IOMAP_F_SHARED, seq); + +convert_delay: + xfs_iunlock(ip, XFS_ILOCK_EXCL); + error = xfs_bmapi_convert_delalloc(ip, XFS_COW_FORK, offset, iomap, + NULL); + if (error) + return error; + /* - * Make sure preallocation does not create extents beyond the range we - * actually support in this filesystem. + * Try the lookup again, because the delalloc conversion might have + * turned the COW mapping into unwritten, but we need it to be in + * written state. */ - if (last_fsb > XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes)) - last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes); + goto retry; +out_unlock: + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; +} - ASSERT(last_fsb > offset_fsb); +const struct iomap_ops xfs_atomic_write_cow_iomap_ops = { + .iomap_begin = xfs_atomic_write_cow_iomap_begin, +}; + +static int +xfs_dax_write_iomap_end( + struct inode *inode, + loff_t pos, + loff_t length, + ssize_t written, + unsigned flags, + struct iomap *iomap) +{ + struct xfs_inode *ip = XFS_I(inode); - nimaps = XFS_WRITE_IMAPS; - error = xfs_bmapi_delay(ip, offset_fsb, last_fsb - offset_fsb, - imap, &nimaps, XFS_BMAPI_ENTIRE); - switch (error) { - case 0: - case ENOSPC: - case EDQUOT: - break; - default: - return XFS_ERROR(error); + if (!xfs_is_cow_inode(ip)) + return 0; + + if (!written) + return xfs_reflink_cancel_cow_range(ip, pos, length, true); + + return xfs_reflink_end_cow(ip, pos, written); +} + +const struct iomap_ops xfs_dax_write_iomap_ops = { + .iomap_begin = xfs_direct_write_iomap_begin, + .iomap_end = xfs_dax_write_iomap_end, +}; + +/* + * Convert a hole to a delayed allocation. + */ +static void +xfs_bmap_add_extent_hole_delay( + struct xfs_inode *ip, /* incore inode pointer */ + int whichfork, + struct xfs_iext_cursor *icur, + struct xfs_bmbt_irec *new) /* new data to add to file extents */ +{ + struct xfs_ifork *ifp; /* inode fork pointer */ + xfs_bmbt_irec_t left; /* left neighbor extent entry */ + xfs_filblks_t newlen=0; /* new indirect size */ + xfs_filblks_t oldlen=0; /* old indirect size */ + xfs_bmbt_irec_t right; /* right neighbor extent entry */ + uint32_t state = xfs_bmap_fork_to_state(whichfork); + xfs_filblks_t temp; /* temp for indirect calculations */ + + ifp = xfs_ifork_ptr(ip, whichfork); + ASSERT(isnullstartblock(new->br_startblock)); + + /* + * Check and set flags if this segment has a left neighbor + */ + if (xfs_iext_peek_prev_extent(ifp, icur, &left)) { + state |= BMAP_LEFT_VALID; + if (isnullstartblock(left.br_startblock)) + state |= BMAP_LEFT_DELAY; } /* - * If bmapi returned us nothing, we got either ENOSPC or EDQUOT. Retry - * without EOF preallocation. + * Check and set flags if the current (right) segment exists. + * If it doesn't exist, we're converting the hole at end-of-file. */ - if (nimaps == 0) { - trace_xfs_delalloc_enospc(ip, offset, count); - if (prealloc) { - prealloc = 0; - error = 0; - goto retry; - } - return XFS_ERROR(error ? error : ENOSPC); + if (xfs_iext_get_extent(ifp, icur, &right)) { + state |= BMAP_RIGHT_VALID; + if (isnullstartblock(right.br_startblock)) + state |= BMAP_RIGHT_DELAY; } - if (!(imap[0].br_startblock || XFS_IS_REALTIME_INODE(ip))) - return xfs_alert_fsblock_zero(ip, &imap[0]); + /* + * Set contiguity flags on the left and right neighbors. + * Don't let extents get too large, even if the pieces are contiguous. + */ + if ((state & BMAP_LEFT_VALID) && (state & BMAP_LEFT_DELAY) && + left.br_startoff + left.br_blockcount == new->br_startoff && + left.br_blockcount + new->br_blockcount <= XFS_MAX_BMBT_EXTLEN) + state |= BMAP_LEFT_CONTIG; + + if ((state & BMAP_RIGHT_VALID) && (state & BMAP_RIGHT_DELAY) && + new->br_startoff + new->br_blockcount == right.br_startoff && + new->br_blockcount + right.br_blockcount <= XFS_MAX_BMBT_EXTLEN && + (!(state & BMAP_LEFT_CONTIG) || + (left.br_blockcount + new->br_blockcount + + right.br_blockcount <= XFS_MAX_BMBT_EXTLEN))) + state |= BMAP_RIGHT_CONTIG; /* - * Tag the inode as speculatively preallocated so we can reclaim this - * space on demand, if necessary. + * Switch out based on the contiguity flags. */ - if (prealloc) - xfs_inode_set_eofblocks_tag(ip); + switch (state & (BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG)) { + case BMAP_LEFT_CONTIG | BMAP_RIGHT_CONTIG: + /* + * New allocation is contiguous with delayed allocations + * on the left and on the right. + * Merge all three into a single extent record. + */ + temp = left.br_blockcount + new->br_blockcount + + right.br_blockcount; + + oldlen = startblockval(left.br_startblock) + + startblockval(new->br_startblock) + + startblockval(right.br_startblock); + newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp), + oldlen); + left.br_startblock = nullstartblock(newlen); + left.br_blockcount = temp; + + xfs_iext_remove(ip, icur, state); + xfs_iext_prev(ifp, icur); + xfs_iext_update_extent(ip, state, icur, &left); + break; - *ret_imap = imap[0]; - return 0; + case BMAP_LEFT_CONTIG: + /* + * New allocation is contiguous with a delayed allocation + * on the left. + * Merge the new allocation with the left neighbor. + */ + temp = left.br_blockcount + new->br_blockcount; + + oldlen = startblockval(left.br_startblock) + + startblockval(new->br_startblock); + newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp), + oldlen); + left.br_blockcount = temp; + left.br_startblock = nullstartblock(newlen); + + xfs_iext_prev(ifp, icur); + xfs_iext_update_extent(ip, state, icur, &left); + break; + + case BMAP_RIGHT_CONTIG: + /* + * New allocation is contiguous with a delayed allocation + * on the right. + * Merge the new allocation with the right neighbor. + */ + temp = new->br_blockcount + right.br_blockcount; + oldlen = startblockval(new->br_startblock) + + startblockval(right.br_startblock); + newlen = XFS_FILBLKS_MIN(xfs_bmap_worst_indlen(ip, temp), + oldlen); + right.br_startoff = new->br_startoff; + right.br_startblock = nullstartblock(newlen); + right.br_blockcount = temp; + xfs_iext_update_extent(ip, state, icur, &right); + break; + + case 0: + /* + * New allocation is not contiguous with another + * delayed allocation. + * Insert a new entry. + */ + oldlen = newlen = 0; + xfs_iext_insert(ip, icur, new, state); + break; + } + if (oldlen != newlen) { + ASSERT(oldlen > newlen); + xfs_add_fdblocks(ip->i_mount, oldlen - newlen); + + /* + * Nothing to do for disk quota accounting here. + */ + xfs_mod_delalloc(ip, 0, (int64_t)newlen - oldlen); + } } /* - * 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. + * Add a delayed allocation extent to an inode. Blocks are reserved from the + * global pool and the extent inserted into the inode in-core extent tree. * - * Called without a lock on the inode. + * On entry, got refers to the first extent beyond the offset of the extent to + * allocate or eof is specified if no such extent exists. On return, got refers + * to the extent record that was inserted to the inode fork. * - * We no longer bother to look at the incoming map - all we have to - * guarantee is that whatever we allocate fills the required range. + * Note that the allocated extent may have been merged with contiguous extents + * during insertion into the inode fork. Thus, got does not reflect the current + * state of the inode fork on return. If necessary, the caller can use lastx to + * look up the updated record in the inode fork. */ -int -xfs_iomap_write_allocate( - xfs_inode_t *ip, - xfs_off_t offset, - size_t count, - xfs_bmbt_irec_t *imap) +static int +xfs_bmapi_reserve_delalloc( + struct xfs_inode *ip, + int whichfork, + xfs_fileoff_t off, + xfs_filblks_t len, + xfs_filblks_t prealloc, + struct xfs_bmbt_irec *got, + struct xfs_iext_cursor *icur, + int eof) { - xfs_mount_t *mp = ip->i_mount; - xfs_fileoff_t offset_fsb, last_block; - xfs_fileoff_t end_fsb, map_start_fsb; - xfs_fsblock_t first_block; - xfs_bmap_free_t free_list; - xfs_filblks_t count_fsb; - xfs_trans_t *tp; - int nimaps, committed; - int error = 0; - int nres; + struct xfs_mount *mp = ip->i_mount; + struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork); + xfs_extlen_t alen; + xfs_extlen_t indlen; + uint64_t fdblocks; + int error; + xfs_fileoff_t aoff; + bool use_cowextszhint = + whichfork == XFS_COW_FORK && !prealloc; + +retry: + /* + * Cap the alloc length. Keep track of prealloc so we know whether to + * tag the inode before we return. + */ + aoff = off; + alen = XFS_FILBLKS_MIN(len + prealloc, XFS_MAX_BMBT_EXTLEN); + if (!eof) + alen = XFS_FILBLKS_MIN(alen, got->br_startoff - aoff); + if (prealloc && alen >= len) + prealloc = alen - len; /* - * Make sure that the dquots are there. + * If we're targetting the COW fork but aren't creating a speculative + * posteof preallocation, try to expand the reservation to align with + * the COW extent size hint if there's sufficient free space. + * + * Unlike the data fork, the CoW cancellation functions will free all + * the reservations at inactivation, so we don't require that every + * delalloc reservation have a dirty pagecache. */ - error = xfs_qm_dqattach(ip, 0); + if (use_cowextszhint) { + struct xfs_bmbt_irec prev; + xfs_extlen_t extsz = xfs_get_cowextsz_hint(ip); + + if (!xfs_iext_peek_prev_extent(ifp, icur, &prev)) + prev.br_startoff = NULLFILEOFF; + + error = xfs_bmap_extsize_align(mp, got, &prev, extsz, 0, eof, + 1, 0, &aoff, &alen); + ASSERT(!error); + } + + /* + * Make a transaction-less quota reservation for delayed allocation + * blocks. This number gets adjusted later. We return if we haven't + * allocated blocks already inside this loop. + */ + error = xfs_quota_reserve_blkres(ip, alen); if (error) - return XFS_ERROR(error); + goto out; - offset_fsb = XFS_B_TO_FSBT(mp, offset); - count_fsb = imap->br_blockcount; - map_start_fsb = imap->br_startoff; + /* + * Split changing sb for alen and indlen since they could be coming + * from different places. + */ + indlen = (xfs_extlen_t)xfs_bmap_worst_indlen(ip, alen); + ASSERT(indlen > 0); - XFS_STATS_ADD(xs_xstrat_bytes, XFS_FSB_TO_B(mp, count_fsb)); + fdblocks = indlen; + if (XFS_IS_REALTIME_INODE(ip)) { + ASSERT(!xfs_is_zoned_inode(ip)); + error = xfs_dec_frextents(mp, xfs_blen_to_rtbxlen(mp, alen)); + if (error) + goto out_unreserve_quota; + } else { + fdblocks += alen; + } - 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. - */ + error = xfs_dec_fdblocks(mp, fdblocks, false); + if (error) + goto out_unreserve_frextents; - nimaps = 0; - while (nimaps == 0) { - tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE); - tp->t_flags |= XFS_TRANS_RESERVE; - nres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); - error = xfs_trans_reserve(tp, nres, - XFS_WRITE_LOG_RES(mp), - 0, XFS_TRANS_PERM_LOG_RES, - XFS_WRITE_LOG_COUNT); - if (error) { - xfs_trans_cancel(tp, 0); - return XFS_ERROR(error); - } - xfs_ilock(ip, XFS_ILOCK_EXCL); - xfs_trans_ijoin(tp, ip, 0); + ip->i_delayed_blks += alen; + xfs_mod_delalloc(ip, alen, indlen); - xfs_bmap_init(&free_list, &first_block); + got->br_startoff = aoff; + got->br_startblock = nullstartblock(indlen); + got->br_blockcount = alen; + got->br_state = XFS_EXT_NORM; - /* - * 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(NULL, 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; - } - } + xfs_bmap_add_extent_hole_delay(ip, whichfork, icur, got); + + /* + * Tag the inode if blocks were preallocated. Note that COW fork + * preallocation can occur at the start or end of the extent, even when + * prealloc == 0, so we must also check the aligned offset and length. + */ + if (whichfork == XFS_DATA_FORK && prealloc) + xfs_inode_set_eofblocks_tag(ip); + if (whichfork == XFS_COW_FORK && (prealloc || aoff < off || alen > len)) + xfs_inode_set_cowblocks_tag(ip); + + return 0; + +out_unreserve_frextents: + if (XFS_IS_REALTIME_INODE(ip)) + xfs_add_frextents(mp, xfs_blen_to_rtbxlen(mp, alen)); +out_unreserve_quota: + if (XFS_IS_QUOTA_ON(mp)) + xfs_quota_unreserve_blkres(ip, alen); +out: + if (error == -ENOSPC || error == -EDQUOT) { + trace_xfs_delalloc_enospc(ip, off, len); + + if (prealloc || use_cowextszhint) { + /* retry without any preallocation */ + use_cowextszhint = false; + prealloc = 0; + goto retry; + } + } + return error; +} + +static int +xfs_zoned_buffered_write_iomap_begin( + struct inode *inode, + loff_t offset, + loff_t count, + unsigned flags, + struct iomap *iomap, + struct iomap *srcmap) +{ + struct iomap_iter *iter = + container_of(iomap, struct iomap_iter, iomap); + struct xfs_zone_alloc_ctx *ac = iter->private; + 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_iomap_end_fsb(mp, offset, count); + u16 iomap_flags = IOMAP_F_SHARED; + unsigned int lockmode = XFS_ILOCK_EXCL; + xfs_filblks_t count_fsb; + xfs_extlen_t indlen; + struct xfs_bmbt_irec got; + struct xfs_iext_cursor icur; + int error = 0; + + ASSERT(!xfs_get_extsz_hint(ip)); + ASSERT(!(flags & IOMAP_UNSHARE)); + ASSERT(ac); + + if (xfs_is_shutdown(mp)) + return -EIO; + + error = xfs_qm_dqattach(ip); + if (error) + return error; + error = xfs_ilock_for_iomap(ip, flags, &lockmode); + if (error) + return error; + + if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(&ip->i_df)) || + XFS_TEST_ERROR(mp, XFS_ERRTAG_BMAPIFORMAT)) { + xfs_bmap_mark_sick(ip, XFS_DATA_FORK); + error = -EFSCORRUPTED; + goto out_unlock; + } + + XFS_STATS_INC(mp, xs_blk_mapw); + + error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK); + if (error) + goto out_unlock; + + /* + * For zeroing operations check if there is any data to zero first. + * + * For regular writes we always need to allocate new blocks, but need to + * provide the source mapping when the range is unaligned to support + * read-modify-write of the whole block in the page cache. + * + * In either case we need to limit the reported range to the boundaries + * of the source map in the data fork. + */ + if (!IS_ALIGNED(offset, mp->m_sb.sb_blocksize) || + !IS_ALIGNED(offset + count, mp->m_sb.sb_blocksize) || + (flags & IOMAP_ZERO)) { + struct xfs_bmbt_irec smap; + struct xfs_iext_cursor scur; + + if (!xfs_iext_lookup_extent(ip, &ip->i_df, offset_fsb, &scur, + &smap)) + smap.br_startoff = end_fsb; /* fake hole until EOF */ + if (smap.br_startoff > offset_fsb) { /* - * From this point onwards we overwrite the imap - * pointer that the caller gave to us. + * We never need to allocate blocks for zeroing a hole. */ - error = xfs_bmapi_write(tp, ip, map_start_fsb, - count_fsb, - XFS_BMAPI_STACK_SWITCH, - &first_block, 1, - imap, &nimaps, &free_list); + if (flags & IOMAP_ZERO) { + xfs_hole_to_iomap(ip, iomap, offset_fsb, + smap.br_startoff); + goto out_unlock; + } + end_fsb = min(end_fsb, smap.br_startoff); + } else { + end_fsb = min(end_fsb, + smap.br_startoff + smap.br_blockcount); + xfs_trim_extent(&smap, offset_fsb, + end_fsb - offset_fsb); + error = xfs_bmbt_to_iomap(ip, srcmap, &smap, flags, 0, + xfs_iomap_inode_sequence(ip, 0)); if (error) - goto trans_cancel; + goto out_unlock; + } + } - error = xfs_bmap_finish(&tp, &free_list, &committed); - if (error) - goto trans_cancel; + if (!ip->i_cowfp) + xfs_ifork_init_cow(ip); - error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); - if (error) - goto error0; + if (!xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &got)) + got.br_startoff = end_fsb; + if (got.br_startoff <= offset_fsb) { + trace_xfs_reflink_cow_found(ip, &got); + goto done; + } - xfs_iunlock(ip, XFS_ILOCK_EXCL); - } + /* + * Cap the maximum length to keep the chunks of work done here somewhat + * symmetric with the work writeback does. + */ + end_fsb = min(end_fsb, got.br_startoff); + count_fsb = min3(end_fsb - offset_fsb, XFS_MAX_BMBT_EXTLEN, + XFS_B_TO_FSB(mp, 1024 * PAGE_SIZE)); - /* - * 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(xs_xstrat_quick); - return 0; + /* + * The block reservation is supposed to cover all blocks that the + * operation could possible write, but there is a nasty corner case + * where blocks could be stolen from underneath us: + * + * 1) while this thread iterates over a larger buffered write, + * 2) another thread is causing a write fault that calls into + * ->page_mkwrite in range this thread writes to, using up the + * delalloc reservation created by a previous call to this function. + * 3) another thread does direct I/O on the range that the write fault + * happened on, which causes writeback of the dirty data. + * 4) this then set the stale flag, which cuts the current iomap + * iteration short, causing the new call to ->iomap_begin that gets + * us here again, but now without a sufficient reservation. + * + * This is a very unusual I/O pattern, and nothing but generic/095 is + * known to hit it. There's not really much we can do here, so turn this + * into a short write. + */ + if (count_fsb > ac->reserved_blocks) { + xfs_warn_ratelimited(mp, +"Short write on ino 0x%llx comm %.20s due to three-way race with write fault and direct I/O", + ip->i_ino, current->comm); + count_fsb = ac->reserved_blocks; + if (!count_fsb) { + error = -EIO; + goto out_unlock; } - - /* - * 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: - xfs_bmap_cancel(&free_list); - xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT); -error0: - xfs_iunlock(ip, XFS_ILOCK_EXCL); - return XFS_ERROR(error); + error = xfs_quota_reserve_blkres(ip, count_fsb); + if (error) + goto out_unlock; + + indlen = xfs_bmap_worst_indlen(ip, count_fsb); + error = xfs_dec_fdblocks(mp, indlen, false); + if (error) + goto out_unlock; + ip->i_delayed_blks += count_fsb; + xfs_mod_delalloc(ip, count_fsb, indlen); + + got.br_startoff = offset_fsb; + got.br_startblock = nullstartblock(indlen); + got.br_blockcount = count_fsb; + got.br_state = XFS_EXT_NORM; + xfs_bmap_add_extent_hole_delay(ip, XFS_COW_FORK, &icur, &got); + ac->reserved_blocks -= count_fsb; + iomap_flags |= IOMAP_F_NEW; + + trace_xfs_iomap_alloc(ip, offset, XFS_FSB_TO_B(mp, count_fsb), + XFS_COW_FORK, &got); +done: + error = xfs_bmbt_to_iomap(ip, iomap, &got, flags, iomap_flags, + xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED)); +out_unlock: + xfs_iunlock(ip, lockmode); + return error; } -int -xfs_iomap_write_unwritten( - xfs_inode_t *ip, - xfs_off_t offset, - size_t count) +static int +xfs_buffered_write_iomap_begin( + struct inode *inode, + loff_t offset, + loff_t count, + unsigned flags, + struct iomap *iomap, + struct iomap *srcmap) { - xfs_mount_t *mp = ip->i_mount; - xfs_fileoff_t offset_fsb; - xfs_filblks_t count_fsb; - xfs_filblks_t numblks_fsb; - xfs_fsblock_t firstfsb; - int nimaps; - xfs_trans_t *tp; - xfs_bmbt_irec_t imap; - xfs_bmap_free_t free_list; - xfs_fsize_t i_size; - uint resblks; - int committed; - int error; + struct iomap_iter *iter = container_of(iomap, struct iomap_iter, + 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_iomap_end_fsb(mp, offset, count); + 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 allocfork = XFS_DATA_FORK; + int error = 0; + unsigned int lockmode = XFS_ILOCK_EXCL; + unsigned int iomap_flags = 0; + u64 seq; + + if (xfs_is_shutdown(mp)) + return -EIO; + + if (xfs_is_zoned_inode(ip)) + return xfs_zoned_buffered_write_iomap_begin(inode, offset, + count, flags, iomap, srcmap); + + /* we can't use delayed allocations when using extent size hints */ + if (xfs_get_extsz_hint(ip)) + return xfs_direct_write_iomap_begin(inode, offset, count, + flags, iomap, srcmap); + + error = xfs_qm_dqattach(ip); + if (error) + return error; - trace_xfs_unwritten_convert(ip, offset, count); + error = xfs_ilock_for_iomap(ip, flags, &lockmode); + if (error) + return error; - 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); + if (XFS_IS_CORRUPT(mp, !xfs_ifork_has_extents(&ip->i_df)) || + XFS_TEST_ERROR(mp, XFS_ERRTAG_BMAPIFORMAT)) { + xfs_bmap_mark_sick(ip, XFS_DATA_FORK); + error = -EFSCORRUPTED; + goto out_unlock; + } + + XFS_STATS_INC(mp, xs_blk_mapw); + + error = xfs_iread_extents(NULL, ip, XFS_DATA_FORK); + if (error) + goto out_unlock; /* - * 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. + * Search the data 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. */ - resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0) << 1; + 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 or unsharing a hole. */ + if ((flags & (IOMAP_UNSHARE | IOMAP_ZERO)) && + imap.br_startoff > offset_fsb) { + xfs_hole_to_iomap(ip, iomap, offset_fsb, imap.br_startoff); + goto out_unlock; + } + + /* + * For zeroing, trim extents that extend beyond the EOF block. If a + * delalloc extent starts beyond the EOF block, convert it to an + * unwritten extent. + */ + if (flags & IOMAP_ZERO) { + xfs_fileoff_t eof_fsb = XFS_B_TO_FSB(mp, XFS_ISIZE(ip)); + u64 end; + + if (isnullstartblock(imap.br_startblock) && + offset_fsb >= eof_fsb) + goto convert_delay; + if (offset_fsb < eof_fsb && end_fsb > eof_fsb) + end_fsb = eof_fsb; - 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. + * Look up dirty folios for unwritten mappings within EOF. + * Providing this bypasses the flush iomap uses to trigger + * extent conversion when unwritten mappings have dirty + * pagecache in need of zeroing. * - * Note that we open code the transaction allocation here - * to pass KM_NOFS--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. + * Trim the mapping to the end pos of the lookup, which in turn + * was trimmed to the end of the batch if it became full before + * the end of the mapping. */ - sb_start_intwrite(mp->m_super); - tp = _xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE, KM_NOFS); - tp->t_flags |= XFS_TRANS_RESERVE | XFS_TRANS_FREEZE_PROT; - error = xfs_trans_reserve(tp, resblks, - XFS_WRITE_LOG_RES(mp), 0, - XFS_TRANS_PERM_LOG_RES, - XFS_WRITE_LOG_COUNT); - if (error) { - xfs_trans_cancel(tp, 0); - return XFS_ERROR(error); + if (imap.br_state == XFS_EXT_UNWRITTEN && + offset_fsb < eof_fsb) { + loff_t len = min(count, + XFS_FSB_TO_B(mp, imap.br_blockcount)); + + end = iomap_fill_dirty_folios(iter, offset, len); + end_fsb = min_t(xfs_fileoff_t, end_fsb, + XFS_B_TO_FSB(mp, end)); } - xfs_ilock(ip, XFS_ILOCK_EXCL); - xfs_trans_ijoin(tp, ip, 0); + xfs_trim_extent(&imap, offset_fsb, end_fsb - 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); + goto found_cow; + } + } + + if (imap.br_startoff <= offset_fsb) { /* - * Modify the unwritten extent state of the buffer. + * For reflink files we may need a delalloc reservation when + * overwriting shared extents. This includes zeroing of + * existing extents that contain data. */ - xfs_bmap_init(&free_list, &firstfsb); - nimaps = 1; - error = xfs_bmapi_write(tp, ip, offset_fsb, count_fsb, - XFS_BMAPI_CONVERT, &firstfsb, - 1, &imap, &nimaps, &free_list); + 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 found_imap; + } + + xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb); + + /* Trim the mapping to the nearest shared extent boundary. */ + error = xfs_bmap_trim_cow(ip, &imap, &shared); if (error) - goto error_on_bmapi_transaction; + 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 found_imap; + } /* - * 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. + * Fork all the shared blocks from our write offset until the + * end of the extent. */ - i_size = XFS_FSB_TO_B(mp, offset_fsb + count_fsb); - if (i_size > offset + count) - i_size = offset + count; + allocfork = 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 = xfs_iomap_end_fsb(mp, offset, count); - 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); + if (xfs_is_always_cow_inode(ip)) + allocfork = XFS_COW_FORK; + } + + if (eof && offset + count > XFS_ISIZE(ip)) { + /* + * Determine the initial size of the preallocation. + * We clean up any extra preallocation when the file is closed. + */ + if (xfs_has_allocsize(mp)) + prealloc_blocks = mp->m_allocsize_blocks; + else if (allocfork == XFS_DATA_FORK) + prealloc_blocks = xfs_iomap_prealloc_size(ip, allocfork, + offset, count, &icur); + else + prealloc_blocks = xfs_iomap_prealloc_size(ip, allocfork, + offset, count, &ccur); + if (prealloc_blocks) { + xfs_extlen_t align; + xfs_off_t end_offset; + xfs_fileoff_t p_end_fsb; + + end_offset = XFS_ALLOC_ALIGN(mp, offset + count - 1); + p_end_fsb = XFS_B_TO_FSBT(mp, end_offset) + + prealloc_blocks; + + align = xfs_eof_alignment(ip); + if (align) + p_end_fsb = roundup_64(p_end_fsb, align); + + p_end_fsb = min(p_end_fsb, + XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes)); + ASSERT(p_end_fsb > offset_fsb); + prealloc_blocks = p_end_fsb - end_fsb; } + } - error = xfs_bmap_finish(&tp, &free_list, &committed); + /* + * 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; + if (allocfork == XFS_COW_FORK) { + error = xfs_bmapi_reserve_delalloc(ip, allocfork, offset_fsb, + end_fsb - offset_fsb, prealloc_blocks, &cmap, + &ccur, cow_eof); if (error) - goto error_on_bmapi_transaction; + goto out_unlock; - error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES); - xfs_iunlock(ip, XFS_ILOCK_EXCL); + trace_xfs_iomap_alloc(ip, offset, count, allocfork, &cmap); + goto found_cow; + } + + error = xfs_bmapi_reserve_delalloc(ip, allocfork, offset_fsb, + end_fsb - offset_fsb, prealloc_blocks, &imap, &icur, + eof); + if (error) + goto out_unlock; + + trace_xfs_iomap_alloc(ip, offset, count, allocfork, &imap); +found_imap: + seq = xfs_iomap_inode_sequence(ip, iomap_flags); + xfs_iunlock(ip, lockmode); + return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, iomap_flags, seq); + +convert_delay: + xfs_iunlock(ip, lockmode); + truncate_pagecache(inode, offset); + error = xfs_bmapi_convert_delalloc(ip, XFS_DATA_FORK, offset, + iomap, NULL); + if (error) + return error; + + trace_xfs_iomap_alloc(ip, offset, count, XFS_DATA_FORK, &imap); + return 0; + +found_cow: + if (imap.br_startoff <= offset_fsb) { + error = xfs_bmbt_to_iomap(ip, srcmap, &imap, flags, 0, + xfs_iomap_inode_sequence(ip, 0)); if (error) - return XFS_ERROR(error); + goto out_unlock; + } else { + xfs_trim_extent(&cmap, offset_fsb, + imap.br_startoff - offset_fsb); + } - if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip))) - return xfs_alert_fsblock_zero(ip, &imap); + iomap_flags |= IOMAP_F_SHARED; + seq = xfs_iomap_inode_sequence(ip, iomap_flags); + xfs_iunlock(ip, lockmode); + return xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, iomap_flags, seq); - 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); +out_unlock: + xfs_iunlock(ip, lockmode); + return error; +} + +static void +xfs_buffered_write_delalloc_punch( + struct inode *inode, + loff_t offset, + loff_t length, + struct iomap *iomap) +{ + struct iomap_iter *iter = + container_of(iomap, struct iomap_iter, iomap); + + xfs_bmap_punch_delalloc_range(XFS_I(inode), + (iomap->flags & IOMAP_F_SHARED) ? + XFS_COW_FORK : XFS_DATA_FORK, + offset, offset + length, iter->private); +} + +static int +xfs_buffered_write_iomap_end( + struct inode *inode, + loff_t offset, + loff_t length, + ssize_t written, + unsigned flags, + struct iomap *iomap) +{ + loff_t start_byte, end_byte; + + /* If we didn't reserve the blocks, we're not allowed to punch them. */ + if (iomap->type != IOMAP_DELALLOC || !(iomap->flags & IOMAP_F_NEW)) + return 0; + + /* + * iomap_page_mkwrite() will never fail in a way that requires delalloc + * extents that it allocated to be revoked. Hence never try to release + * them here. + */ + if (flags & IOMAP_FAULT) + return 0; + + /* Nothing to do if we've written the entire delalloc extent */ + start_byte = iomap_last_written_block(inode, offset, written); + end_byte = round_up(offset + length, i_blocksize(inode)); + if (start_byte >= end_byte) + return 0; + + /* For zeroing operations the callers already hold invalidate_lock. */ + if (flags & (IOMAP_UNSHARE | IOMAP_ZERO)) { + rwsem_assert_held_write(&inode->i_mapping->invalidate_lock); + iomap_write_delalloc_release(inode, start_byte, end_byte, flags, + iomap, xfs_buffered_write_delalloc_punch); + } else { + filemap_invalidate_lock(inode->i_mapping); + iomap_write_delalloc_release(inode, start_byte, end_byte, flags, + iomap, xfs_buffered_write_delalloc_punch); + filemap_invalidate_unlock(inode->i_mapping); + } return 0; +} -error_on_bmapi_transaction: - xfs_bmap_cancel(&free_list); - xfs_trans_cancel(tp, (XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT)); - xfs_iunlock(ip, XFS_ILOCK_EXCL); - return XFS_ERROR(error); +const struct iomap_ops xfs_buffered_write_iomap_ops = { + .iomap_begin = xfs_buffered_write_iomap_begin, + .iomap_end = xfs_buffered_write_iomap_end, +}; + +static int +xfs_read_iomap_begin( + struct inode *inode, + loff_t offset, + loff_t length, + unsigned flags, + struct iomap *iomap, + struct iomap *srcmap) +{ + struct xfs_inode *ip = XFS_I(inode); + struct xfs_mount *mp = ip->i_mount; + struct xfs_bmbt_irec imap; + xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); + xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, length); + int nimaps = 1, error = 0; + bool shared = false; + unsigned int lockmode = XFS_ILOCK_SHARED; + u64 seq; + + ASSERT(!(flags & (IOMAP_WRITE | IOMAP_ZERO))); + + if (xfs_is_shutdown(mp)) + return -EIO; + + error = xfs_ilock_for_iomap(ip, flags, &lockmode); + if (error) + return error; + error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap, + &nimaps, 0); + if (!error && ((flags & IOMAP_REPORT) || IS_DAX(inode))) + error = xfs_reflink_trim_around_shared(ip, &imap, &shared); + seq = xfs_iomap_inode_sequence(ip, shared ? IOMAP_F_SHARED : 0); + xfs_iunlock(ip, lockmode); + + if (error) + return error; + trace_xfs_iomap_found(ip, offset, length, XFS_DATA_FORK, &imap); + return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, + shared ? IOMAP_F_SHARED : 0, seq); +} + +const struct iomap_ops xfs_read_iomap_ops = { + .iomap_begin = xfs_read_iomap_begin, +}; + +static int +xfs_seek_iomap_begin( + struct inode *inode, + loff_t offset, + loff_t length, + unsigned flags, + struct iomap *iomap, + struct iomap *srcmap) +{ + 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; + u64 seq; + + if (xfs_is_shutdown(mp)) + return -EIO; + + lockmode = xfs_ilock_data_map_shared(ip); + 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 = xfs_iomap_end_fsb(mp, offset, length); + } + + /* + * 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 - offset_fsb); + seq = xfs_iomap_inode_sequence(ip, IOMAP_F_SHARED); + error = xfs_bmbt_to_iomap(ip, iomap, &cmap, flags, + IOMAP_F_SHARED, seq); + /* + * 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: + seq = xfs_iomap_inode_sequence(ip, 0); + xfs_trim_extent(&imap, offset_fsb, end_fsb - offset_fsb); + error = xfs_bmbt_to_iomap(ip, iomap, &imap, flags, 0, seq); +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 iomap *srcmap) +{ + 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; + int seq; + + if (xfs_is_shutdown(mp)) + return -EIO; + + lockmode = xfs_ilock_attr_map_shared(ip); + + /* if there are no attribute fork or extents, return ENOENT */ + if (!xfs_inode_has_attr_fork(ip) || !ip->i_af.if_nextents) { + error = -ENOENT; + goto out_unlock; + } + + ASSERT(ip->i_af.if_format != XFS_DINODE_FMT_LOCAL); + error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap, + &nimaps, XFS_BMAPI_ATTRFORK); +out_unlock: + + seq = xfs_iomap_inode_sequence(ip, IOMAP_F_XATTR); + xfs_iunlock(ip, lockmode); + + if (error) + return error; + ASSERT(nimaps); + return xfs_bmbt_to_iomap(ip, iomap, &imap, flags, IOMAP_F_XATTR, seq); +} + +const struct iomap_ops xfs_xattr_iomap_ops = { + .iomap_begin = xfs_xattr_iomap_begin, +}; + +int +xfs_zero_range( + struct xfs_inode *ip, + loff_t pos, + loff_t len, + struct xfs_zone_alloc_ctx *ac, + bool *did_zero) +{ + struct inode *inode = VFS_I(ip); + + xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL); + + if (IS_DAX(inode)) + return dax_zero_range(inode, pos, len, did_zero, + &xfs_dax_write_iomap_ops); + return iomap_zero_range(inode, pos, len, did_zero, + &xfs_buffered_write_iomap_ops, &xfs_iomap_write_ops, + ac); +} + +int +xfs_truncate_page( + struct xfs_inode *ip, + loff_t pos, + struct xfs_zone_alloc_ctx *ac, + bool *did_zero) +{ + struct inode *inode = VFS_I(ip); + + if (IS_DAX(inode)) + return dax_truncate_page(inode, pos, did_zero, + &xfs_dax_write_iomap_ops); + return iomap_truncate_page(inode, pos, did_zero, + &xfs_buffered_write_iomap_ops, &xfs_iomap_write_ops, + ac); } |