From 6778948f9de86c3cfaf36725a7c87dcff9ba247f Mon Sep 17 00:00:00 2001 From: hc <hc@nodka.com> Date: Mon, 11 Dec 2023 08:20:59 +0000 Subject: [PATCH] kernel_5.10 no rt --- kernel/fs/xfs/xfs_reflink.c | 1047 ++++++++++++++++++++++----------------------------------- 1 files changed, 412 insertions(+), 635 deletions(-) diff --git a/kernel/fs/xfs/xfs_reflink.c b/kernel/fs/xfs/xfs_reflink.c index 0b159a7..aa46b75 100644 --- a/kernel/fs/xfs/xfs_reflink.c +++ b/kernel/fs/xfs/xfs_reflink.c @@ -11,21 +11,12 @@ #include "xfs_trans_resv.h" #include "xfs_mount.h" #include "xfs_defer.h" -#include "xfs_da_format.h" -#include "xfs_da_btree.h" #include "xfs_inode.h" #include "xfs_trans.h" -#include "xfs_inode_item.h" #include "xfs_bmap.h" #include "xfs_bmap_util.h" -#include "xfs_error.h" -#include "xfs_dir2.h" -#include "xfs_dir2_priv.h" -#include "xfs_ioctl.h" #include "xfs_trace.h" -#include "xfs_log.h" #include "xfs_icache.h" -#include "xfs_pnfs.h" #include "xfs_btree.h" #include "xfs_refcount_btree.h" #include "xfs_refcount.h" @@ -33,11 +24,9 @@ #include "xfs_trans_space.h" #include "xfs_bit.h" #include "xfs_alloc.h" -#include "xfs_quota_defs.h" #include "xfs_quota.h" #include "xfs_reflink.h" #include "xfs_iomap.h" -#include "xfs_rmap_btree.h" #include "xfs_sb.h" #include "xfs_ag_resv.h" @@ -154,8 +143,6 @@ error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp); if (error) return error; - if (!agbp) - return -ENOMEM; cur = xfs_refcountbt_init_cursor(mp, tp, agbp, agno); @@ -182,8 +169,7 @@ xfs_reflink_trim_around_shared( struct xfs_inode *ip, struct xfs_bmbt_irec *irec, - bool *shared, - bool *trimmed) + bool *shared) { xfs_agnumber_t agno; xfs_agblock_t agbno; @@ -193,7 +179,7 @@ int error = 0; /* Holes, unwritten, and delalloc extents cannot be shared */ - if (!xfs_is_reflink_inode(ip) || !xfs_bmap_is_real_extent(irec)) { + if (!xfs_is_cow_inode(ip) || !xfs_bmap_is_written_extent(irec)) { *shared = false; return 0; } @@ -209,7 +195,7 @@ if (error) return error; - *shared = *trimmed = false; + *shared = false; if (fbno == NULLAGBLOCK) { /* No shared blocks at all. */ return 0; @@ -222,8 +208,6 @@ */ irec->br_blockcount = flen; *shared = true; - if (flen != aglen) - *trimmed = true; return 0; } else { /* @@ -233,100 +217,63 @@ * start of the shared region. */ irec->br_blockcount = fbno - agbno; - *trimmed = true; return 0; } } -/* - * Trim the passed in imap to the next shared/unshared extent boundary, and - * if imap->br_startoff points to a shared extent reserve space for it in the - * COW fork. In this case *shared is set to true, else to false. - * - * Note that imap will always contain the block numbers for the existing blocks - * in the data fork, as the upper layers need them for read-modify-write - * operations. - */ int -xfs_reflink_reserve_cow( +xfs_bmap_trim_cow( struct xfs_inode *ip, struct xfs_bmbt_irec *imap, bool *shared) { - struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); - struct xfs_bmbt_irec got; - int error = 0; - bool eof = false, trimmed; - struct xfs_iext_cursor icur; - - /* - * Search the COW fork extent list first. This serves two purposes: - * first this implement the speculative preallocation using cowextisze, - * so that we also unshared 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_iext_lookup_extent(ip, ifp, imap->br_startoff, &icur, &got)) - eof = true; - if (!eof && got.br_startoff <= imap->br_startoff) { - trace_xfs_reflink_cow_found(ip, imap); - xfs_trim_extent(imap, got.br_startoff, got.br_blockcount); - + /* We can't update any real extents in always COW mode. */ + if (xfs_is_always_cow_inode(ip) && + !isnullstartblock(imap->br_startblock)) { *shared = true; return 0; } /* Trim the mapping to the nearest shared extent boundary. */ - error = xfs_reflink_trim_around_shared(ip, imap, shared, &trimmed); - if (error) - return error; - - /* Not shared? Just report the (potentially capped) extent. */ - if (!*shared) - return 0; - - /* - * Fork all the shared blocks from our write offset until the end of - * the extent. - */ - error = xfs_qm_dqattach_locked(ip, false); - if (error) - return error; - - error = xfs_bmapi_reserve_delalloc(ip, XFS_COW_FORK, imap->br_startoff, - imap->br_blockcount, 0, &got, &icur, eof); - if (error == -ENOSPC || error == -EDQUOT) - trace_xfs_reflink_cow_enospc(ip, imap); - if (error) - return error; - - xfs_trim_extent(imap, got.br_startoff, got.br_blockcount); - trace_xfs_reflink_cow_alloc(ip, &got); - return 0; + return xfs_reflink_trim_around_shared(ip, imap, shared); } -/* Convert part of an unwritten CoW extent to a real one. */ -STATIC int -xfs_reflink_convert_cow_extent( - struct xfs_inode *ip, - struct xfs_bmbt_irec *imap, - xfs_fileoff_t offset_fsb, - xfs_filblks_t count_fsb) +static int +xfs_reflink_convert_cow_locked( + struct xfs_inode *ip, + xfs_fileoff_t offset_fsb, + xfs_filblks_t count_fsb) { - int nimaps = 1; + struct xfs_iext_cursor icur; + struct xfs_bmbt_irec got; + struct xfs_btree_cur *dummy_cur = NULL; + int dummy_logflags; + int error = 0; - if (imap->br_state == XFS_EXT_NORM) + if (!xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &got)) return 0; - xfs_trim_extent(imap, offset_fsb, count_fsb); - trace_xfs_reflink_convert_cow(ip, imap); - if (imap->br_blockcount == 0) - return 0; - return xfs_bmapi_write(NULL, ip, imap->br_startoff, imap->br_blockcount, - XFS_BMAPI_COWFORK | XFS_BMAPI_CONVERT, 0, imap, - &nimaps); + do { + if (got.br_startoff >= offset_fsb + count_fsb) + break; + if (got.br_state == XFS_EXT_NORM) + continue; + if (WARN_ON_ONCE(isnullstartblock(got.br_startblock))) + return -EIO; + + xfs_trim_extent(&got, offset_fsb, count_fsb); + if (!got.br_blockcount) + continue; + + got.br_state = XFS_EXT_NORM; + error = xfs_bmap_add_extent_unwritten_real(NULL, ip, + XFS_COW_FORK, &icur, &dummy_cur, &got, + &dummy_logflags); + if (error) + return error; + } while (xfs_iext_next_extent(ip->i_cowfp, &icur, &got)); + + return error; } /* Convert all of the unwritten CoW extents in a file's range to real ones. */ @@ -340,15 +287,12 @@ xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset); xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, offset + count); xfs_filblks_t count_fsb = end_fsb - offset_fsb; - struct xfs_bmbt_irec imap; - int nimaps = 1, error = 0; + int error; ASSERT(count != 0); xfs_ilock(ip, XFS_ILOCK_EXCL); - error = xfs_bmapi_write(NULL, ip, offset_fsb, count_fsb, - XFS_BMAPI_COWFORK | XFS_BMAPI_CONVERT | - XFS_BMAPI_CONVERT_ONLY, 0, &imap, &nimaps); + error = xfs_reflink_convert_cow_locked(ip, offset_fsb, count_fsb); xfs_iunlock(ip, XFS_ILOCK_EXCL); return error; } @@ -362,14 +306,13 @@ xfs_find_trim_cow_extent( struct xfs_inode *ip, struct xfs_bmbt_irec *imap, + struct xfs_bmbt_irec *cmap, bool *shared, bool *found) { xfs_fileoff_t offset_fsb = imap->br_startoff; xfs_filblks_t count_fsb = imap->br_blockcount; struct xfs_iext_cursor icur; - struct xfs_bmbt_irec got; - bool trimmed; *found = false; @@ -377,19 +320,22 @@ * If we don't find an overlapping extent, trim the range we need to * allocate to fit the hole we found. */ - if (!xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &got) || - got.br_startoff > offset_fsb) - return xfs_reflink_trim_around_shared(ip, imap, shared, &trimmed); + if (!xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, cmap)) + cmap->br_startoff = offset_fsb + count_fsb; + if (cmap->br_startoff > offset_fsb) { + xfs_trim_extent(imap, imap->br_startoff, + cmap->br_startoff - imap->br_startoff); + return xfs_bmap_trim_cow(ip, imap, shared); + } *shared = true; - if (isnullstartblock(got.br_startblock)) { - xfs_trim_extent(imap, got.br_startoff, got.br_blockcount); + if (isnullstartblock(cmap->br_startblock)) { + xfs_trim_extent(imap, cmap->br_startoff, cmap->br_blockcount); return 0; } /* real extent found - no need to allocate */ - xfs_trim_extent(&got, offset_fsb, count_fsb); - *imap = got; + xfs_trim_extent(cmap, offset_fsb, count_fsb); *found = true; return 0; } @@ -399,8 +345,10 @@ xfs_reflink_allocate_cow( struct xfs_inode *ip, struct xfs_bmbt_irec *imap, + struct xfs_bmbt_irec *cmap, bool *shared, - uint *lockmode) + uint *lockmode, + bool convert_now) { struct xfs_mount *mp = ip->i_mount; xfs_fileoff_t offset_fsb = imap->br_startoff; @@ -412,9 +360,12 @@ xfs_extlen_t resblks = 0; ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); - ASSERT(xfs_is_reflink_inode(ip)); + if (!ip->i_cowfp) { + ASSERT(!xfs_is_reflink_inode(ip)); + xfs_ifork_init_cow(ip); + } - error = xfs_find_trim_cow_extent(ip, imap, shared, &found); + error = xfs_find_trim_cow_extent(ip, imap, cmap, shared, &found); if (error || !*shared) return error; if (found) @@ -439,7 +390,7 @@ /* * Check for an overlapping extent again now that we dropped the ilock. */ - error = xfs_find_trim_cow_extent(ip, imap, shared, &found); + error = xfs_find_trim_cow_extent(ip, imap, cmap, shared, &found); if (error || !*shared) goto out_trans_cancel; if (found) { @@ -457,8 +408,8 @@ /* Allocate the entire reservation as unwritten blocks. */ nimaps = 1; error = xfs_bmapi_write(tp, ip, imap->br_startoff, imap->br_blockcount, - XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC, - resblks, imap, &nimaps); + XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC, 0, cmap, + &nimaps); if (error) goto out_unreserve; @@ -474,7 +425,16 @@ if (nimaps == 0) return -ENOSPC; convert: - return xfs_reflink_convert_cow_extent(ip, imap, offset_fsb, count_fsb); + xfs_trim_extent(cmap, offset_fsb, count_fsb); + /* + * COW fork extents are supposed to remain unwritten until we're ready + * to initiate a disk write. For direct I/O we are going to write the + * data and need the conversion, but for buffered writes we're done. + */ + if (!convert_now || cmap->br_state == XFS_EXT_NORM) + return 0; + trace_xfs_reflink_convert_cow(ip, cmap); + return xfs_reflink_convert_cow_locked(ip, offset_fsb, count_fsb); out_unreserve: xfs_trans_unreserve_quota_nblks(tp, ip, (long)resblks, 0, @@ -533,10 +493,8 @@ ASSERT((*tpp)->t_firstblock == NULLFSBLOCK); /* Free the CoW orphan record. */ - error = xfs_refcount_free_cow_extent(*tpp, - del.br_startblock, del.br_blockcount); - if (error) - break; + xfs_refcount_free_cow_extent(*tpp, del.br_startblock, + del.br_blockcount); xfs_bmap_add_free(*tpp, del.br_startblock, del.br_blockcount, NULL); @@ -589,7 +547,7 @@ int error; trace_xfs_reflink_cancel_cow_range(ip, offset, count); - ASSERT(xfs_is_reflink_inode(ip)); + ASSERT(ip->i_cowfp); offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); if (count == NULLFILEOFF) @@ -599,7 +557,7 @@ /* Start a rolling transaction to remove the mappings */ error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, - 0, 0, XFS_TRANS_NOFS, &tp); + 0, 0, 0, &tp); if (error) goto out; @@ -626,54 +584,47 @@ } /* - * Remap parts of a file's data fork after a successful CoW. + * Remap part of the CoW fork into the data fork. + * + * We aim to remap the range starting at @offset_fsb and ending at @end_fsb + * into the data fork; this function will remap what it can (at the end of the + * range) and update @end_fsb appropriately. Each remap gets its own + * transaction because we can end up merging and splitting bmbt blocks for + * every remap operation and we'd like to keep the block reservation + * requirements as low as possible. */ -int -xfs_reflink_end_cow( - struct xfs_inode *ip, - xfs_off_t offset, - xfs_off_t count) +STATIC int +xfs_reflink_end_cow_extent( + struct xfs_inode *ip, + xfs_fileoff_t offset_fsb, + xfs_fileoff_t *end_fsb) { - struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); - struct xfs_bmbt_irec got, del; - struct xfs_trans *tp; - xfs_fileoff_t offset_fsb; - xfs_fileoff_t end_fsb; - int error; - unsigned int resblks; - xfs_filblks_t rlen; - struct xfs_iext_cursor icur; - - trace_xfs_reflink_end_cow(ip, offset, count); + struct xfs_bmbt_irec got, del; + struct xfs_iext_cursor icur; + struct xfs_mount *mp = ip->i_mount; + struct xfs_trans *tp; + struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); + xfs_filblks_t rlen; + unsigned int resblks; + int error; /* No COW extents? That's easy! */ - if (ifp->if_bytes == 0) + if (ifp->if_bytes == 0) { + *end_fsb = offset_fsb; return 0; + } - offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); - end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count); + resblks = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, + XFS_TRANS_RESERVE, &tp); + if (error) + return error; /* - * Start a rolling transaction to switch the mappings. We're - * unlikely ever to have to remap 16T worth of single-block - * extents, so just cap the worst case extent count to 2^32-1. - * Stick a warning in just in case, and avoid 64-bit division. + * Lock the inode. We have to ijoin without automatic unlock because + * the lead transaction is the refcountbt record deletion; the data + * fork update follows as a deferred log item. */ - BUILD_BUG_ON(MAX_RW_COUNT > UINT_MAX); - if (end_fsb - offset_fsb > UINT_MAX) { - error = -EFSCORRUPTED; - xfs_force_shutdown(ip->i_mount, SHUTDOWN_CORRUPT_INCORE); - ASSERT(0); - goto out; - } - resblks = XFS_NEXTENTADD_SPACE_RES(ip->i_mount, - (unsigned int)(end_fsb - offset_fsb), - XFS_DATA_FORK); - error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, - resblks, 0, XFS_TRANS_RESERVE | XFS_TRANS_NOFS, &tp); - if (error) - goto out; - xfs_ilock(ip, XFS_ILOCK_EXCL); xfs_trans_ijoin(tp, ip, 0); @@ -682,80 +633,126 @@ * left by the time I/O completes for the loser of the race. In that * case we are done. */ - if (!xfs_iext_lookup_extent_before(ip, ifp, &end_fsb, &icur, &got)) + if (!xfs_iext_lookup_extent_before(ip, ifp, end_fsb, &icur, &got) || + got.br_startoff + got.br_blockcount <= offset_fsb) { + *end_fsb = offset_fsb; + goto out_cancel; + } + + /* + * Structure copy @got into @del, then trim @del to the range that we + * were asked to remap. We preserve @got for the eventual CoW fork + * deletion; from now on @del represents the mapping that we're + * actually remapping. + */ + del = got; + xfs_trim_extent(&del, offset_fsb, *end_fsb - offset_fsb); + + ASSERT(del.br_blockcount > 0); + + /* + * Only remap real extents that contain data. With AIO, speculative + * preallocations can leak into the range we are called upon, and we + * need to skip them. + */ + if (!xfs_bmap_is_written_extent(&got)) { + *end_fsb = del.br_startoff; + goto out_cancel; + } + + /* Unmap the old blocks in the data fork. */ + rlen = del.br_blockcount; + error = __xfs_bunmapi(tp, ip, del.br_startoff, &rlen, 0, 1); + if (error) goto out_cancel; - /* Walk backwards until we're out of the I/O range... */ - while (got.br_startoff + got.br_blockcount > offset_fsb) { - del = got; - xfs_trim_extent(&del, offset_fsb, end_fsb - offset_fsb); + /* Trim the extent to whatever got unmapped. */ + xfs_trim_extent(&del, del.br_startoff + rlen, del.br_blockcount - rlen); + trace_xfs_reflink_cow_remap(ip, &del); - /* Extent delete may have bumped ext forward */ - if (!del.br_blockcount) - goto prev_extent; + /* Free the CoW orphan record. */ + xfs_refcount_free_cow_extent(tp, del.br_startblock, del.br_blockcount); - /* - * Only remap real extent that contain data. With AIO - * speculatively preallocations can leak into the range we - * are called upon, and we need to skip them. - */ - if (!xfs_bmap_is_real_extent(&got)) - goto prev_extent; + /* Map the new blocks into the data fork. */ + xfs_bmap_map_extent(tp, ip, &del); - /* Unmap the old blocks in the data fork. */ - ASSERT(tp->t_firstblock == NULLFSBLOCK); - rlen = del.br_blockcount; - error = __xfs_bunmapi(tp, ip, del.br_startoff, &rlen, 0, 1); - if (error) - goto out_cancel; + /* Charge this new data fork mapping to the on-disk quota. */ + xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_DELBCOUNT, + (long)del.br_blockcount); - /* Trim the extent to whatever got unmapped. */ - if (rlen) { - xfs_trim_extent(&del, del.br_startoff + rlen, - del.br_blockcount - rlen); - } - trace_xfs_reflink_cow_remap(ip, &del); - - /* Free the CoW orphan record. */ - error = xfs_refcount_free_cow_extent(tp, del.br_startblock, - del.br_blockcount); - if (error) - goto out_cancel; - - /* Map the new blocks into the data fork. */ - error = xfs_bmap_map_extent(tp, ip, &del); - if (error) - goto out_cancel; - - /* Charge this new data fork mapping to the on-disk quota. */ - xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_DELBCOUNT, - (long)del.br_blockcount); - - /* Remove the mapping from the CoW fork. */ - xfs_bmap_del_extent_cow(ip, &icur, &got, &del); - - error = xfs_defer_finish(&tp); - if (error) - goto out_cancel; - if (!xfs_iext_get_extent(ifp, &icur, &got)) - break; - continue; -prev_extent: - if (!xfs_iext_prev_extent(ifp, &icur, &got)) - break; - } + /* Remove the mapping from the CoW fork. */ + xfs_bmap_del_extent_cow(ip, &icur, &got, &del); error = xfs_trans_commit(tp); xfs_iunlock(ip, XFS_ILOCK_EXCL); if (error) - goto out; + return error; + + /* Update the caller about how much progress we made. */ + *end_fsb = del.br_startoff; return 0; out_cancel: xfs_trans_cancel(tp); xfs_iunlock(ip, XFS_ILOCK_EXCL); -out: - trace_xfs_reflink_end_cow_error(ip, error, _RET_IP_); + return error; +} + +/* + * Remap parts of a file's data fork after a successful CoW. + */ +int +xfs_reflink_end_cow( + struct xfs_inode *ip, + xfs_off_t offset, + xfs_off_t count) +{ + xfs_fileoff_t offset_fsb; + xfs_fileoff_t end_fsb; + int error = 0; + + trace_xfs_reflink_end_cow(ip, offset, count); + + offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); + end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count); + + /* + * Walk backwards until we're out of the I/O range. The loop function + * repeatedly cycles the ILOCK to allocate one transaction per remapped + * extent. + * + * If we're being called by writeback then the pages will still + * have PageWriteback set, which prevents races with reflink remapping + * and truncate. Reflink remapping prevents races with writeback by + * taking the iolock and mmaplock before flushing the pages and + * remapping, which means there won't be any further writeback or page + * cache dirtying until the reflink completes. + * + * We should never have two threads issuing writeback for the same file + * region. There are also have post-eof checks in the writeback + * preparation code so that we don't bother writing out pages that are + * about to be truncated. + * + * If we're being called as part of directio write completion, the dio + * count is still elevated, which reflink and truncate will wait for. + * Reflink remapping takes the iolock and mmaplock and waits for + * pending dio to finish, which should prevent any directio until the + * remap completes. Multiple concurrent directio writes to the same + * region are handled by end_cow processing only occurring for the + * threads which succeed; the outcome of multiple overlapping direct + * writes is not well defined anyway. + * + * It's possible that a buffered write and a direct write could collide + * here (the buffered write stumbles in after the dio flushes and + * invalidates the page cache and immediately queues writeback), but we + * have never supported this 100%. If either disk write succeeds the + * blocks will be remapped. + */ + while (end_fsb > offset_fsb && !error) + error = xfs_reflink_end_cow_extent(ip, offset_fsb, &end_fsb); + + if (error) + trace_xfs_reflink_end_cow_error(ip, error, _RET_IP_); return error; } @@ -917,18 +914,18 @@ /* * Update destination inode size & cowextsize hint, if necessary. */ -STATIC int +int xfs_reflink_update_dest( struct xfs_inode *dest, xfs_off_t newlen, xfs_extlen_t cowextsize, - bool is_dedupe) + unsigned int remap_flags) { struct xfs_mount *mp = dest->i_mount; struct xfs_trans *tp; int error; - if (is_dedupe && newlen <= i_size_read(VFS_I(dest)) && cowextsize == 0) + if (newlen <= i_size_read(VFS_I(dest)) && cowextsize == 0) return 0; error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ichange, 0, 0, 0, &tp); @@ -949,10 +946,6 @@ dest->i_d.di_flags2 |= XFS_DIFLAG2_COWEXTSIZE; } - if (!is_dedupe) { - xfs_trans_ichgtime(tp, dest, - XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); - } xfs_trans_log_inode(tp, dest, XFS_ILOG_CORE); error = xfs_trans_commit(tp); @@ -991,41 +984,28 @@ } /* - * Unmap a range of blocks from a file, then map other blocks into the hole. - * The range to unmap is (destoff : destoff + srcioff + irec->br_blockcount). - * The extent irec is mapped into dest at irec->br_startoff. + * Remap the given extent into the file. The dmap blockcount will be set to + * the number of blocks that were actually remapped. */ STATIC int xfs_reflink_remap_extent( struct xfs_inode *ip, - struct xfs_bmbt_irec *irec, - xfs_fileoff_t destoff, + struct xfs_bmbt_irec *dmap, xfs_off_t new_isize) { + struct xfs_bmbt_irec smap; struct xfs_mount *mp = ip->i_mount; - bool real_extent = xfs_bmap_is_real_extent(irec); struct xfs_trans *tp; - unsigned int resblks; - struct xfs_bmbt_irec uirec; - xfs_filblks_t rlen; - xfs_filblks_t unmap_len; xfs_off_t newlen; - int64_t qres; + int64_t qres, qdelta; + unsigned int resblks; + bool smap_real; + bool dmap_written = xfs_bmap_is_written_extent(dmap); + int nimaps; int error; - unmap_len = irec->br_startoff + irec->br_blockcount - destoff; - trace_xfs_reflink_punch_range(ip, destoff, unmap_len); - - /* No reflinking if we're low on space */ - if (real_extent) { - error = xfs_reflink_ag_has_free_space(mp, - XFS_FSB_TO_AGNO(mp, irec->br_startblock)); - if (error) - goto out; - } - /* Start a rolling transaction to switch the mappings */ - resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK); + resblks = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp); if (error) goto out; @@ -1034,116 +1014,172 @@ xfs_trans_ijoin(tp, ip, 0); /* - * Reserve quota for this operation. We don't know if the first unmap - * in the dest file will cause a bmap btree split, so we always reserve - * at least enough blocks for that split. If the extent being mapped - * in is written, we need to reserve quota for that too. + * Read what's currently mapped in the destination file into smap. + * If smap isn't a hole, we will have to remove it before we can add + * dmap to the destination file. */ - qres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); - if (real_extent) - qres += irec->br_blockcount; - error = xfs_trans_reserve_quota_nblks(tp, ip, qres, 0, - XFS_QMOPT_RES_REGBLKS); + nimaps = 1; + error = xfs_bmapi_read(ip, dmap->br_startoff, dmap->br_blockcount, + &smap, &nimaps, 0); if (error) goto out_cancel; + ASSERT(nimaps == 1 && smap.br_startoff == dmap->br_startoff); + smap_real = xfs_bmap_is_real_extent(&smap); - trace_xfs_reflink_remap(ip, irec->br_startoff, - irec->br_blockcount, irec->br_startblock); + /* + * We can only remap as many blocks as the smaller of the two extent + * maps, because we can only remap one extent at a time. + */ + dmap->br_blockcount = min(dmap->br_blockcount, smap.br_blockcount); + ASSERT(dmap->br_blockcount == smap.br_blockcount); - /* Unmap the old blocks in the data fork. */ - rlen = unmap_len; - while (rlen) { - ASSERT(tp->t_firstblock == NULLFSBLOCK); - error = __xfs_bunmapi(tp, ip, destoff, &rlen, 0, 1); - if (error) - goto out_cancel; + trace_xfs_reflink_remap_extent_dest(ip, &smap); - /* - * Trim the extent to whatever got unmapped. - * Remember, bunmapi works backwards. - */ - uirec.br_startblock = irec->br_startblock + rlen; - uirec.br_startoff = irec->br_startoff + rlen; - uirec.br_blockcount = unmap_len - rlen; - uirec.br_state = irec->br_state; - unmap_len = rlen; + /* + * Two extents mapped to the same physical block must not have + * different states; that's filesystem corruption. Move on to the next + * extent if they're both holes or both the same physical extent. + */ + if (dmap->br_startblock == smap.br_startblock) { + if (dmap->br_state != smap.br_state) + error = -EFSCORRUPTED; + goto out_cancel; + } - /* If this isn't a real mapping, we're done. */ - if (!real_extent || uirec.br_blockcount == 0) - goto next_extent; + /* If both extents are unwritten, leave them alone. */ + if (dmap->br_state == XFS_EXT_UNWRITTEN && + smap.br_state == XFS_EXT_UNWRITTEN) + goto out_cancel; - trace_xfs_reflink_remap(ip, uirec.br_startoff, - uirec.br_blockcount, uirec.br_startblock); - - /* Update the refcount tree */ - error = xfs_refcount_increase_extent(tp, &uirec); - if (error) - goto out_cancel; - - /* Map the new blocks into the data fork. */ - error = xfs_bmap_map_extent(tp, ip, &uirec); - if (error) - goto out_cancel; - - /* Update quota accounting. */ - xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, - uirec.br_blockcount); - - /* Update dest isize if needed. */ - newlen = XFS_FSB_TO_B(mp, - uirec.br_startoff + uirec.br_blockcount); - newlen = min_t(xfs_off_t, newlen, new_isize); - if (newlen > i_size_read(VFS_I(ip))) { - trace_xfs_reflink_update_inode_size(ip, newlen); - i_size_write(VFS_I(ip), newlen); - ip->i_d.di_size = newlen; - xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); - } - -next_extent: - /* Process all the deferred stuff. */ - error = xfs_defer_finish(&tp); + /* No reflinking if the AG of the dest mapping is low on space. */ + if (dmap_written) { + error = xfs_reflink_ag_has_free_space(mp, + XFS_FSB_TO_AGNO(mp, dmap->br_startblock)); if (error) goto out_cancel; } + /* + * Compute quota reservation if we think the quota block counter for + * this file could increase. + * + * Adding a written extent to the extent map can cause a bmbt split, + * and removing a mapped extent from the extent can cause a bmbt split. + * The two operations cannot both cause a split since they operate on + * the same index in the bmap btree, so we only need a reservation for + * one bmbt split if either thing is happening. + * + * If we are mapping a written extent into the file, we need to have + * enough quota block count reservation to handle the blocks in that + * extent. We log only the delta to the quota block counts, so if the + * extent we're unmapping also has blocks allocated to it, we don't + * need a quota reservation for the extent itself. + * + * Note that if we're replacing a delalloc reservation with a written + * extent, we have to take the full quota reservation because removing + * the delalloc reservation gives the block count back to the quota + * count. This is suboptimal, but the VFS flushed the dest range + * before we started. That should have removed all the delalloc + * reservations, but we code defensively. + */ + qres = qdelta = 0; + if (smap_real || dmap_written) + qres = XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK); + if (!smap_real && dmap_written) + qres += dmap->br_blockcount; + if (qres > 0) { + error = xfs_trans_reserve_quota_nblks(tp, ip, qres, 0, + XFS_QMOPT_RES_REGBLKS); + if (error) + goto out_cancel; + } + + if (smap_real) { + /* + * If the extent we're unmapping is backed by storage (written + * or not), unmap the extent and drop its refcount. + */ + xfs_bmap_unmap_extent(tp, ip, &smap); + xfs_refcount_decrease_extent(tp, &smap); + qdelta -= smap.br_blockcount; + } else if (smap.br_startblock == DELAYSTARTBLOCK) { + xfs_filblks_t len = smap.br_blockcount; + + /* + * If the extent we're unmapping is a delalloc reservation, + * we can use the regular bunmapi function to release the + * incore state. Dropping the delalloc reservation takes care + * of the quota reservation for us. + */ + error = __xfs_bunmapi(NULL, ip, smap.br_startoff, &len, 0, 1); + if (error) + goto out_cancel; + ASSERT(len == 0); + } + + /* + * If the extent we're sharing is backed by written storage, increase + * its refcount and map it into the file. + */ + if (dmap_written) { + xfs_refcount_increase_extent(tp, dmap); + xfs_bmap_map_extent(tp, ip, dmap); + qdelta += dmap->br_blockcount; + } + + xfs_trans_mod_dquot_byino(tp, ip, XFS_TRANS_DQ_BCOUNT, qdelta); + + /* Update dest isize if needed. */ + newlen = XFS_FSB_TO_B(mp, dmap->br_startoff + dmap->br_blockcount); + newlen = min_t(xfs_off_t, newlen, new_isize); + if (newlen > i_size_read(VFS_I(ip))) { + trace_xfs_reflink_update_inode_size(ip, newlen); + i_size_write(VFS_I(ip), newlen); + ip->i_d.di_size = newlen; + xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); + } + + /* Commit everything and unlock. */ error = xfs_trans_commit(tp); - xfs_iunlock(ip, XFS_ILOCK_EXCL); - if (error) - goto out; - return 0; + goto out_unlock; out_cancel: xfs_trans_cancel(tp); +out_unlock: xfs_iunlock(ip, XFS_ILOCK_EXCL); out: - trace_xfs_reflink_remap_extent_error(ip, error, _RET_IP_); + if (error) + trace_xfs_reflink_remap_extent_error(ip, error, _RET_IP_); return error; } -/* - * Iteratively remap one file's extents (and holes) to another's. - */ -STATIC int +/* Remap a range of one file to the other. */ +int xfs_reflink_remap_blocks( struct xfs_inode *src, - xfs_fileoff_t srcoff, + loff_t pos_in, struct xfs_inode *dest, - xfs_fileoff_t destoff, - xfs_filblks_t len, - xfs_off_t new_isize) + loff_t pos_out, + loff_t remap_len, + loff_t *remapped) { struct xfs_bmbt_irec imap; + struct xfs_mount *mp = src->i_mount; + xfs_fileoff_t srcoff = XFS_B_TO_FSBT(mp, pos_in); + xfs_fileoff_t destoff = XFS_B_TO_FSBT(mp, pos_out); + xfs_filblks_t len; + xfs_filblks_t remapped_len = 0; + xfs_off_t new_isize = pos_out + remap_len; int nimaps; int error = 0; - xfs_filblks_t range_len; - /* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */ - while (len) { - uint lock_mode; + len = min_t(xfs_filblks_t, XFS_B_TO_FSB(mp, remap_len), + XFS_MAX_FILEOFF); - trace_xfs_reflink_remap_blocks_loop(src, srcoff, len, - dest, destoff); + trace_xfs_reflink_remap_blocks(src, srcoff, len, dest, destoff); + + while (len > 0) { + unsigned int lock_mode; /* Read extent from the source file */ nimaps = 1; @@ -1151,102 +1187,46 @@ error = xfs_bmapi_read(src, srcoff, len, &imap, &nimaps, 0); xfs_iunlock(src, lock_mode); if (error) - goto err; - ASSERT(nimaps == 1); + break; + /* + * The caller supposedly flushed all dirty pages in the source + * file range, which means that writeback should have allocated + * or deleted all delalloc reservations in that range. If we + * find one, that's a good sign that something is seriously + * wrong here. + */ + ASSERT(nimaps == 1 && imap.br_startoff == srcoff); + if (imap.br_startblock == DELAYSTARTBLOCK) { + ASSERT(imap.br_startblock != DELAYSTARTBLOCK); + error = -EFSCORRUPTED; + break; + } - trace_xfs_reflink_remap_imap(src, srcoff, len, XFS_IO_OVERWRITE, - &imap); + trace_xfs_reflink_remap_extent_src(src, &imap); - /* Translate imap into the destination file. */ - range_len = imap.br_startoff + imap.br_blockcount - srcoff; - imap.br_startoff += destoff - srcoff; - - /* Clear dest from destoff to the end of imap and map it in. */ - error = xfs_reflink_remap_extent(dest, &imap, destoff, - new_isize); + /* Remap into the destination file at the given offset. */ + imap.br_startoff = destoff; + error = xfs_reflink_remap_extent(dest, &imap, new_isize); if (error) - goto err; + break; if (fatal_signal_pending(current)) { error = -EINTR; - goto err; + break; } /* Advance drange/srange */ - srcoff += range_len; - destoff += range_len; - len -= range_len; + srcoff += imap.br_blockcount; + destoff += imap.br_blockcount; + len -= imap.br_blockcount; + remapped_len += imap.br_blockcount; } - return 0; - -err: - trace_xfs_reflink_remap_blocks_error(dest, error, _RET_IP_); + if (error) + trace_xfs_reflink_remap_blocks_error(dest, error, _RET_IP_); + *remapped = min_t(loff_t, remap_len, + XFS_FSB_TO_B(src->i_mount, remapped_len)); return error; -} - -/* - * Grab the exclusive iolock for a data copy from src to dest, making - * sure to abide vfs locking order (lowest pointer value goes first) and - * breaking the pnfs layout leases on dest before proceeding. The loop - * is needed because we cannot call the blocking break_layout() with the - * src iolock held, and therefore have to back out both locks. - */ -static int -xfs_iolock_two_inodes_and_break_layout( - struct inode *src, - struct inode *dest) -{ - int error; - -retry: - if (src < dest) { - inode_lock_shared(src); - inode_lock_nested(dest, I_MUTEX_NONDIR2); - } else { - /* src >= dest */ - inode_lock(dest); - } - - error = break_layout(dest, false); - if (error == -EWOULDBLOCK) { - inode_unlock(dest); - if (src < dest) - inode_unlock_shared(src); - error = break_layout(dest, true); - if (error) - return error; - goto retry; - } - if (error) { - inode_unlock(dest); - if (src < dest) - inode_unlock_shared(src); - return error; - } - if (src > dest) - inode_lock_shared_nested(src, I_MUTEX_NONDIR2); - return 0; -} - -/* Unlock both inodes after they've been prepped for a range clone. */ -STATIC void -xfs_reflink_remap_unlock( - struct file *file_in, - struct file *file_out) -{ - struct inode *inode_in = file_inode(file_in); - struct xfs_inode *src = XFS_I(inode_in); - struct inode *inode_out = file_inode(file_out); - struct xfs_inode *dest = XFS_I(inode_out); - bool same_inode = (inode_in == inode_out); - - xfs_iunlock(dest, XFS_MMAPLOCK_EXCL); - if (!same_inode) - xfs_iunlock(src, XFS_MMAPLOCK_SHARED); - inode_unlock(inode_out); - if (!same_inode) - inode_unlock_shared(inode_in); } /* @@ -1266,7 +1246,7 @@ trace_xfs_zero_eof(ip, isize, pos - isize); return iomap_zero_range(VFS_I(ip), isize, pos - isize, NULL, - &xfs_iomap_ops); + &xfs_buffered_write_iomap_ops); } /* @@ -1298,32 +1278,25 @@ * stale data in the destination file. Hence we reject these clone attempts with * -EINVAL in this case. */ -STATIC int +int xfs_reflink_remap_prep( struct file *file_in, loff_t pos_in, struct file *file_out, loff_t pos_out, - u64 *len, - bool is_dedupe) + loff_t *len, + unsigned int remap_flags) { struct inode *inode_in = file_inode(file_in); struct xfs_inode *src = XFS_I(inode_in); struct inode *inode_out = file_inode(file_out); struct xfs_inode *dest = XFS_I(inode_out); - bool same_inode = (inode_in == inode_out); - u64 blkmask = i_blocksize(inode_in) - 1; - ssize_t ret; + int ret; /* Lock both files against IO */ - ret = xfs_iolock_two_inodes_and_break_layout(inode_in, inode_out); + ret = xfs_ilock2_io_mmap(src, dest); if (ret) return ret; - if (same_inode) - xfs_ilock(src, XFS_MMAPLOCK_EXCL); - else - xfs_lock_two_inodes(src, XFS_MMAPLOCK_SHARED, dest, - XFS_MMAPLOCK_EXCL); /* Check file eligibility and prepare for block sharing. */ ret = -EINVAL; @@ -1335,28 +1308,10 @@ if (IS_DAX(inode_in) || IS_DAX(inode_out)) goto out_unlock; - ret = vfs_clone_file_prep_inodes(inode_in, pos_in, inode_out, pos_out, - len, is_dedupe); - if (ret <= 0) + ret = generic_remap_file_range_prep(file_in, pos_in, file_out, pos_out, + len, remap_flags); + if (ret || *len == 0) goto out_unlock; - - /* - * If the dedupe data matches, chop off the partial EOF block - * from the source file so we don't try to dedupe the partial - * EOF block. - */ - if (is_dedupe) { - *len &= ~blkmask; - } else if (*len & blkmask) { - /* - * The user is attempting to share a partial EOF block, - * if it's inside the destination EOF then reject it. - */ - if (pos_out + *len < i_size_read(inode_out)) { - ret = -EINVAL; - goto out_unlock; - } - } /* Attach dquots to dest inode before changing block map */ ret = xfs_qm_dqattach(dest); @@ -1390,178 +1345,10 @@ if (ret) goto out_unlock; - /* If we're altering the file contents... */ - if (!is_dedupe) { - /* - * ...update the timestamps (which will grab the ilock again - * from xfs_fs_dirty_inode, so we have to call it before we - * take the ilock). - */ - if (!(file_out->f_mode & FMODE_NOCMTIME)) { - ret = file_update_time(file_out); - if (ret) - goto out_unlock; - } - - /* - * ...clear the security bits if the process is not being run - * by root. This keeps people from modifying setuid and setgid - * binaries. - */ - ret = file_remove_privs(file_out); - if (ret) - goto out_unlock; - } - - return 1; + return 0; out_unlock: - xfs_reflink_remap_unlock(file_in, file_out); + xfs_iunlock2_io_mmap(src, dest); return ret; -} - -/* - * Link a range of blocks from one file to another. - */ -int -xfs_reflink_remap_range( - struct file *file_in, - loff_t pos_in, - struct file *file_out, - loff_t pos_out, - u64 len, - bool is_dedupe) -{ - struct inode *inode_in = file_inode(file_in); - struct xfs_inode *src = XFS_I(inode_in); - struct inode *inode_out = file_inode(file_out); - struct xfs_inode *dest = XFS_I(inode_out); - struct xfs_mount *mp = src->i_mount; - xfs_fileoff_t sfsbno, dfsbno; - xfs_filblks_t fsblen; - xfs_extlen_t cowextsize; - ssize_t ret; - - if (!xfs_sb_version_hasreflink(&mp->m_sb)) - return -EOPNOTSUPP; - - if (XFS_FORCED_SHUTDOWN(mp)) - return -EIO; - - /* Prepare and then clone file data. */ - ret = xfs_reflink_remap_prep(file_in, pos_in, file_out, pos_out, - &len, is_dedupe); - if (ret <= 0) - return ret; - - trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); - - dfsbno = XFS_B_TO_FSBT(mp, pos_out); - sfsbno = XFS_B_TO_FSBT(mp, pos_in); - fsblen = XFS_B_TO_FSB(mp, len); - ret = xfs_reflink_remap_blocks(src, sfsbno, dest, dfsbno, fsblen, - pos_out + len); - if (ret) - goto out_unlock; - - /* - * Carry the cowextsize hint from src to dest if we're sharing the - * entire source file to the entire destination file, the source file - * has a cowextsize hint, and the destination file does not. - */ - cowextsize = 0; - if (pos_in == 0 && len == i_size_read(inode_in) && - (src->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) && - pos_out == 0 && len >= i_size_read(inode_out) && - !(dest->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE)) - cowextsize = src->i_d.di_cowextsize; - - ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize, - is_dedupe); - -out_unlock: - xfs_reflink_remap_unlock(file_in, file_out); - if (ret) - trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_); - return ret; -} - -/* - * The user wants to preemptively CoW all shared blocks in this file, - * which enables us to turn off the reflink flag. Iterate all - * extents which are not prealloc/delalloc to see which ranges are - * mentioned in the refcount tree, then read those blocks into the - * pagecache, dirty them, fsync them back out, and then we can update - * the inode flag. What happens if we run out of memory? :) - */ -STATIC int -xfs_reflink_dirty_extents( - struct xfs_inode *ip, - xfs_fileoff_t fbno, - xfs_filblks_t end, - xfs_off_t isize) -{ - struct xfs_mount *mp = ip->i_mount; - xfs_agnumber_t agno; - xfs_agblock_t agbno; - xfs_extlen_t aglen; - xfs_agblock_t rbno; - xfs_extlen_t rlen; - xfs_off_t fpos; - xfs_off_t flen; - struct xfs_bmbt_irec map[2]; - int nmaps; - int error = 0; - - while (end - fbno > 0) { - nmaps = 1; - /* - * Look for extents in the file. Skip holes, delalloc, or - * unwritten extents; they can't be reflinked. - */ - error = xfs_bmapi_read(ip, fbno, end - fbno, map, &nmaps, 0); - if (error) - goto out; - if (nmaps == 0) - break; - if (!xfs_bmap_is_real_extent(&map[0])) - goto next; - - map[1] = map[0]; - while (map[1].br_blockcount) { - agno = XFS_FSB_TO_AGNO(mp, map[1].br_startblock); - agbno = XFS_FSB_TO_AGBNO(mp, map[1].br_startblock); - aglen = map[1].br_blockcount; - - error = xfs_reflink_find_shared(mp, NULL, agno, agbno, - aglen, &rbno, &rlen, true); - if (error) - goto out; - if (rbno == NULLAGBLOCK) - break; - - /* Dirty the pages */ - xfs_iunlock(ip, XFS_ILOCK_EXCL); - fpos = XFS_FSB_TO_B(mp, map[1].br_startoff + - (rbno - agbno)); - flen = XFS_FSB_TO_B(mp, rlen); - if (fpos + flen > isize) - flen = isize - fpos; - error = iomap_file_dirty(VFS_I(ip), fpos, flen, - &xfs_iomap_ops); - xfs_ilock(ip, XFS_ILOCK_EXCL); - if (error) - goto out; - - map[1].br_blockcount -= (rbno - agbno + rlen); - map[1].br_startoff += (rbno - agbno + rlen); - map[1].br_startblock += (rbno - agbno + rlen); - } - -next: - fbno = map[0].br_startoff + map[0].br_blockcount; - } -out: - return error; } /* Does this inode need the reflink flag? */ @@ -1640,7 +1427,8 @@ * We didn't find any shared blocks so turn off the reflink flag. * First, get rid of any leftover CoW mappings. */ - error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF, true); + error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, XFS_MAX_FILEOFF, + true); if (error) return error; @@ -1700,10 +1488,7 @@ xfs_off_t offset, xfs_off_t len) { - struct xfs_mount *mp = ip->i_mount; - xfs_fileoff_t fbno; - xfs_filblks_t end; - xfs_off_t isize; + struct inode *inode = VFS_I(ip); int error; if (!xfs_is_reflink_inode(ip)) @@ -1711,20 +1496,15 @@ trace_xfs_reflink_unshare(ip, offset, len); - inode_dio_wait(VFS_I(ip)); + inode_dio_wait(inode); - /* Try to CoW the selected ranges */ - xfs_ilock(ip, XFS_ILOCK_EXCL); - fbno = XFS_B_TO_FSBT(mp, offset); - isize = i_size_read(VFS_I(ip)); - end = XFS_B_TO_FSB(mp, offset + len); - error = xfs_reflink_dirty_extents(ip, fbno, end, isize); + error = iomap_file_unshare(inode, offset, len, + &xfs_buffered_write_iomap_ops); if (error) - goto out_unlock; - xfs_iunlock(ip, XFS_ILOCK_EXCL); + goto out; - /* Wait for the IO to finish */ - error = filemap_write_and_wait(VFS_I(ip)->i_mapping); + error = filemap_write_and_wait_range(inode->i_mapping, offset, + offset + len - 1); if (error) goto out; @@ -1732,11 +1512,8 @@ error = xfs_reflink_try_clear_inode_flag(ip); if (error) goto out; - return 0; -out_unlock: - xfs_iunlock(ip, XFS_ILOCK_EXCL); out: trace_xfs_reflink_unshare_error(ip, error, _RET_IP_); return error; -- Gitblit v1.6.2