diff options
Diffstat (limited to 'fs/xfs/xfs_reflink.c')
-rw-r--r-- | fs/xfs/xfs_reflink.c | 351 |
1 files changed, 201 insertions, 150 deletions
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 38f405415b88..ecdb086bc23e 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -182,8 +182,7 @@ int 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; @@ -209,7 +208,7 @@ xfs_reflink_trim_around_shared( if (error) return error; - *shared = *trimmed = false; + *shared = false; if (fbno == NULLAGBLOCK) { /* No shared blocks at all. */ return 0; @@ -222,8 +221,6 @@ xfs_reflink_trim_around_shared( */ irec->br_blockcount = flen; *shared = true; - if (flen != aglen) - *trimmed = true; return 0; } else { /* @@ -233,7 +230,6 @@ xfs_reflink_trim_around_shared( * start of the shared region. */ irec->br_blockcount = fbno - agbno; - *trimmed = true; return 0; } } @@ -241,7 +237,7 @@ xfs_reflink_trim_around_shared( /* * 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. + * COW fork. * * 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 @@ -250,14 +246,14 @@ xfs_reflink_trim_around_shared( int xfs_reflink_reserve_cow( struct xfs_inode *ip, - struct xfs_bmbt_irec *imap, - bool *shared) + struct xfs_bmbt_irec *imap) { struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK); struct xfs_bmbt_irec got; int error = 0; - bool eof = false, trimmed; + bool eof = false; struct xfs_iext_cursor icur; + bool shared; /* * Search the COW fork extent list first. This serves two purposes: @@ -273,18 +269,16 @@ xfs_reflink_reserve_cow( 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); - - *shared = true; return 0; } /* Trim the mapping to the nearest shared extent boundary. */ - error = xfs_reflink_trim_around_shared(ip, imap, shared, &trimmed); + error = xfs_reflink_trim_around_shared(ip, imap, &shared); if (error) return error; /* Not shared? Just report the (potentially capped) extent. */ - if (!*shared) + if (!shared) return 0; /* @@ -352,6 +346,50 @@ xfs_reflink_convert_cow( return error; } +/* + * Find the extent that maps the given range in the COW fork. Even if the extent + * is not shared we might have a preallocation for it in the COW fork. If so we + * use it that rather than trigger a new allocation. + */ +static int +xfs_find_trim_cow_extent( + struct xfs_inode *ip, + struct xfs_bmbt_irec *imap, + 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; + + *found = false; + + /* + * 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 + count_fsb; + if (got.br_startoff > offset_fsb) { + xfs_trim_extent(imap, imap->br_startoff, + got.br_startoff - imap->br_startoff); + return xfs_reflink_trim_around_shared(ip, imap, shared); + } + + *shared = true; + if (isnullstartblock(got.br_startblock)) { + xfs_trim_extent(imap, got.br_startoff, got.br_blockcount); + return 0; + } + + /* real extent found - no need to allocate */ + xfs_trim_extent(&got, offset_fsb, count_fsb); + *imap = got; + *found = true; + return 0; +} + /* Allocate all CoW reservations covering a range of blocks in a file. */ int xfs_reflink_allocate_cow( @@ -363,78 +401,64 @@ xfs_reflink_allocate_cow( struct xfs_mount *mp = ip->i_mount; xfs_fileoff_t offset_fsb = imap->br_startoff; xfs_filblks_t count_fsb = imap->br_blockcount; - struct xfs_bmbt_irec got; - struct xfs_trans *tp = NULL; + struct xfs_trans *tp; int nimaps, error = 0; - bool trimmed; + bool found; xfs_filblks_t resaligned; xfs_extlen_t resblks = 0; - struct xfs_iext_cursor icur; -retry: - ASSERT(xfs_is_reflink_inode(ip)); ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); + ASSERT(xfs_is_reflink_inode(ip)); - /* - * Even if the extent is not shared we might have a preallocation for - * it in the COW fork. If so use it. - */ - if (xfs_iext_lookup_extent(ip, ip->i_cowfp, offset_fsb, &icur, &got) && - got.br_startoff <= offset_fsb) { - *shared = true; - - /* If we have a real allocation in the COW fork we're done. */ - if (!isnullstartblock(got.br_startblock)) { - xfs_trim_extent(&got, offset_fsb, count_fsb); - *imap = got; - goto convert; - } + error = xfs_find_trim_cow_extent(ip, imap, shared, &found); + if (error || !*shared) + return error; + if (found) + goto convert; - xfs_trim_extent(imap, got.br_startoff, got.br_blockcount); - } else { - error = xfs_reflink_trim_around_shared(ip, imap, shared, &trimmed); - if (error || !*shared) - goto out; - } + resaligned = xfs_aligned_fsb_count(imap->br_startoff, + imap->br_blockcount, xfs_get_cowextsz_hint(ip)); + resblks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned); - if (!tp) { - resaligned = xfs_aligned_fsb_count(imap->br_startoff, - imap->br_blockcount, xfs_get_cowextsz_hint(ip)); - resblks = XFS_DIOSTRAT_SPACE_RES(mp, resaligned); + xfs_iunlock(ip, *lockmode); + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp); + *lockmode = XFS_ILOCK_EXCL; + xfs_ilock(ip, *lockmode); - xfs_iunlock(ip, *lockmode); - error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, 0, &tp); - *lockmode = XFS_ILOCK_EXCL; - xfs_ilock(ip, *lockmode); + if (error) + return error; - if (error) - return error; + error = xfs_qm_dqattach_locked(ip, false); + if (error) + goto out_trans_cancel; - error = xfs_qm_dqattach_locked(ip, false); - if (error) - goto out; - goto retry; + /* + * Check for an overlapping extent again now that we dropped the ilock. + */ + error = xfs_find_trim_cow_extent(ip, imap, shared, &found); + if (error || !*shared) + goto out_trans_cancel; + if (found) { + xfs_trans_cancel(tp); + goto convert; } error = xfs_trans_reserve_quota_nblks(tp, ip, resblks, 0, XFS_QMOPT_RES_REGBLKS); if (error) - goto out; + goto out_trans_cancel; xfs_trans_ijoin(tp, ip, 0); - nimaps = 1; - /* 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); if (error) - goto out_trans_cancel; + goto out_unreserve; xfs_inode_set_cowblocks_tag(ip); - - /* Finish up. */ error = xfs_trans_commit(tp); if (error) return error; @@ -447,12 +471,12 @@ retry: return -ENOSPC; convert: return xfs_reflink_convert_cow_extent(ip, imap, offset_fsb, count_fsb); -out_trans_cancel: + +out_unreserve: xfs_trans_unreserve_quota_nblks(tp, ip, (long)resblks, 0, XFS_QMOPT_RES_REGBLKS); -out: - if (tp) - xfs_trans_cancel(tp); +out_trans_cancel: + xfs_trans_cancel(tp); return error; } @@ -666,14 +690,12 @@ xfs_reflink_end_cow( if (!del.br_blockcount) goto prev_extent; - ASSERT(!isnullstartblock(got.br_startblock)); - /* - * Don't remap unwritten extents; these are - * speculatively preallocated CoW extents that have been - * allocated but have not yet been involved in a write. + * 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 (got.br_state == XFS_EXT_UNWRITTEN) + if (!xfs_bmap_is_real_extent(&got)) goto prev_extent; /* Unmap the old blocks in the data fork. */ @@ -891,18 +913,18 @@ out_error: /* * 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); @@ -923,10 +945,6 @@ xfs_reflink_update_dest( 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); @@ -1090,19 +1108,28 @@ out: /* * Iteratively remap one file's extents (and holes) to another's. */ -STATIC int +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; + xfs_fileoff_t srcoff; + xfs_fileoff_t destoff; + xfs_filblks_t len; + xfs_filblks_t range_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; + + destoff = XFS_B_TO_FSBT(src->i_mount, pos_out); + srcoff = XFS_B_TO_FSBT(src->i_mount, pos_in); + len = XFS_B_TO_FSB(src->i_mount, remap_len); /* drange = (destoff, destoff + len); srange = (srcoff, srcoff + len) */ while (len) { @@ -1117,7 +1144,7 @@ xfs_reflink_remap_blocks( error = xfs_bmapi_read(src, srcoff, len, &imap, &nimaps, 0); xfs_iunlock(src, lock_mode); if (error) - goto err; + break; ASSERT(nimaps == 1); trace_xfs_reflink_remap_imap(src, srcoff, len, XFS_IO_OVERWRITE, @@ -1131,23 +1158,24 @@ xfs_reflink_remap_blocks( error = xfs_reflink_remap_extent(dest, &imap, destoff, 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; + remapped_len += range_len; } - 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; } @@ -1195,35 +1223,91 @@ retry: return 0; } +/* Unlock both inodes after they've been prepped for a range clone. */ +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); +} + /* - * Link a range of blocks from one file to another. + * If we're reflinking to a point past the destination file's EOF, we must + * zero any speculative post-EOF preallocations that sit between the old EOF + * and the destination file offset. + */ +static int +xfs_reflink_zero_posteof( + struct xfs_inode *ip, + loff_t pos) +{ + loff_t isize = i_size_read(VFS_I(ip)); + + if (pos <= isize) + return 0; + + trace_xfs_zero_eof(ip, isize, pos - isize); + return iomap_zero_range(VFS_I(ip), isize, pos - isize, NULL, + &xfs_iomap_ops); +} + +/* + * Prepare two files for range cloning. Upon a successful return both inodes + * will have the iolock and mmaplock held, the page cache of the out file will + * be truncated, and any leases on the out file will have been broken. This + * function borrows heavily from xfs_file_aio_write_checks. + * + * The VFS allows partial EOF blocks to "match" for dedupe even though it hasn't + * checked that the bytes beyond EOF physically match. Hence we cannot use the + * EOF block in the source dedupe range because it's not a complete block match, + * hence can introduce a corruption into the file that has it's block replaced. + * + * In similar fashion, the VFS file cloning also allows partial EOF blocks to be + * "block aligned" for the purposes of cloning entire files. However, if the + * source file range includes the EOF block and it lands within the existing EOF + * of the destination file, then we can expose stale data from beyond the source + * file EOF in the destination file. + * + * XFS doesn't support partial block sharing, so in both cases we have check + * these cases ourselves. For dedupe, we can simply round the length to dedupe + * down to the previous whole block and ignore the partial EOF block. While this + * means we can't dedupe the last block of a file, this is an acceptible + * tradeoff for simplicity on implementation. + * + * For cloning, we want to share the partial EOF block if it is also the new EOF + * block of the destination file. If the partial EOF block lies inside the + * existing destination EOF, then we have to abort the clone to avoid exposing + * stale data in the destination file. Hence we reject these clone attempts with + * -EINVAL in this case. */ int -xfs_reflink_remap_range( +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); - struct xfs_mount *mp = src->i_mount; bool same_inode = (inode_in == inode_out); - 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; - /* Lock both files against IO */ ret = xfs_iolock_two_inodes_and_break_layout(inode_in, inode_out); if (ret) @@ -1244,9 +1328,9 @@ xfs_reflink_remap_range( 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 < 0 || *len == 0) goto out_unlock; /* Attach dquots to dest inode before changing block map */ @@ -1254,60 +1338,27 @@ xfs_reflink_remap_range( if (ret) goto out_unlock; - trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out); - /* - * Clear out post-eof preallocations because we don't have page cache - * backing the delayed allocations and they'll never get freed on - * their own. + * Zero existing post-eof speculative preallocations in the destination + * file. */ - if (xfs_can_free_eofblocks(dest, true)) { - ret = xfs_free_eofblocks(dest); - if (ret) - goto out_unlock; - } - - /* Set flags and remap blocks. */ - ret = xfs_reflink_set_inode_flag(src, dest); + ret = xfs_reflink_zero_posteof(dest, pos_out); if (ret) goto out_unlock; - 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); + /* Set flags and remap blocks. */ + ret = xfs_reflink_set_inode_flag(src, dest); if (ret) goto out_unlock; /* Zap any page cache for the destination file's range. */ - truncate_inode_pages_range(&inode_out->i_data, pos_out, - PAGE_ALIGN(pos_out + len) - 1); - - /* - * 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); + truncate_inode_pages_range(&inode_out->i_data, + round_down(pos_out, PAGE_SIZE), + round_up(pos_out + *len, PAGE_SIZE) - 1); + return 1; out_unlock: - 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); - if (ret) - trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_); + xfs_reflink_remap_unlock(file_in, file_out); return ret; } |