diff options
Diffstat (limited to 'fs/xfs/xfs_reflink.c')
| -rw-r--r-- | fs/xfs/xfs_reflink.c | 146 |
1 files changed, 115 insertions, 31 deletions
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index cc3b4df88110..ad3bcb76d805 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -293,7 +293,7 @@ xfs_bmap_trim_cow( return xfs_reflink_trim_around_shared(ip, imap, shared); } -static int +int xfs_reflink_convert_cow_locked( struct xfs_inode *ip, xfs_fileoff_t offset_fsb, @@ -786,35 +786,19 @@ xfs_reflink_update_quota( * requirements as low as possible. */ STATIC int -xfs_reflink_end_cow_extent( +xfs_reflink_end_cow_extent_locked( + struct xfs_trans *tp, struct xfs_inode *ip, xfs_fileoff_t *offset_fsb, xfs_fileoff_t end_fsb) { struct xfs_iext_cursor icur; struct xfs_bmbt_irec got, del, data; - struct xfs_mount *mp = ip->i_mount; - struct xfs_trans *tp; struct xfs_ifork *ifp = xfs_ifork_ptr(ip, XFS_COW_FORK); - unsigned int resblks; int nmaps; bool isrt = XFS_IS_REALTIME_INODE(ip); int error; - 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; - - /* - * 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. - */ - xfs_ilock(ip, XFS_ILOCK_EXCL); - xfs_trans_ijoin(tp, ip, 0); - /* * In case of racing, overlapping AIO writes no COW extents might be * left by the time I/O completes for the loser of the race. In that @@ -823,7 +807,7 @@ xfs_reflink_end_cow_extent( if (!xfs_iext_lookup_extent(ip, ifp, *offset_fsb, &icur, &got) || got.br_startoff >= end_fsb) { *offset_fsb = end_fsb; - goto out_cancel; + return 0; } /* @@ -837,7 +821,7 @@ xfs_reflink_end_cow_extent( if (!xfs_iext_next_extent(ifp, &icur, &got) || got.br_startoff >= end_fsb) { *offset_fsb = end_fsb; - goto out_cancel; + return 0; } } del = got; @@ -846,14 +830,14 @@ xfs_reflink_end_cow_extent( error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK, XFS_IEXT_REFLINK_END_COW_CNT); if (error) - goto out_cancel; + return error; /* Grab the corresponding mapping in the data fork. */ nmaps = 1; error = xfs_bmapi_read(ip, del.br_startoff, del.br_blockcount, &data, &nmaps, 0); if (error) - goto out_cancel; + return error; /* We can only remap the smaller of the two extent sizes. */ data.br_blockcount = min(data.br_blockcount, del.br_blockcount); @@ -882,7 +866,7 @@ xfs_reflink_end_cow_extent( error = xfs_bunmapi(NULL, ip, data.br_startoff, data.br_blockcount, 0, 1, &done); if (error) - goto out_cancel; + return error; ASSERT(done); } @@ -899,17 +883,45 @@ xfs_reflink_end_cow_extent( /* 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) - return error; - /* Update the caller about how much progress we made. */ *offset_fsb = del.br_startoff + del.br_blockcount; return 0; +} -out_cancel: - xfs_trans_cancel(tp); +/* + * 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. + */ +STATIC int +xfs_reflink_end_cow_extent( + struct xfs_inode *ip, + xfs_fileoff_t *offset_fsb, + xfs_fileoff_t end_fsb) +{ + struct xfs_mount *mp = ip->i_mount; + struct xfs_trans *tp; + unsigned int resblks; + int error; + + 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; + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, 0); + + error = xfs_reflink_end_cow_extent_locked(tp, ip, offset_fsb, end_fsb); + if (error) + xfs_trans_cancel(tp); + else + error = xfs_trans_commit(tp); xfs_iunlock(ip, XFS_ILOCK_EXCL); return error; } @@ -973,6 +985,78 @@ xfs_reflink_end_cow( } /* + * Fully remap all of the file's data fork at once, which is the critical part + * in achieving atomic behaviour. + * The regular CoW end path does not use function as to keep the block + * reservation per transaction as low as possible. + */ +int +xfs_reflink_end_atomic_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; + struct xfs_mount *mp = ip->i_mount; + struct xfs_trans *tp; + unsigned int resblks; + + trace_xfs_reflink_end_cow(ip, offset, count); + + offset_fsb = XFS_B_TO_FSBT(mp, offset); + end_fsb = XFS_B_TO_FSB(mp, offset + count); + + /* + * Each remapping operation could cause a btree split, so in the worst + * case that's one for each block. + */ + resblks = (end_fsb - offset_fsb) * + XFS_NEXTENTADD_SPACE_RES(mp, 1, XFS_DATA_FORK); + + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_atomic_ioend, resblks, 0, + XFS_TRANS_RESERVE, &tp); + if (error) + return error; + + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, 0); + + while (end_fsb > offset_fsb && !error) { + error = xfs_reflink_end_cow_extent_locked(tp, ip, &offset_fsb, + end_fsb); + } + if (error) { + trace_xfs_reflink_end_cow_error(ip, error, _RET_IP_); + goto out_cancel; + } + error = xfs_trans_commit(tp); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; +out_cancel: + xfs_trans_cancel(tp); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + return error; +} + +/* Compute the largest atomic write that we can complete through software. */ +xfs_extlen_t +xfs_reflink_max_atomic_cow( + struct xfs_mount *mp) +{ + /* We cannot do any atomic writes without out of place writes. */ + if (!xfs_can_sw_atomic_write(mp)) + return 0; + + /* + * Atomic write limits must always be a power-of-2, according to + * generic_atomic_write_valid. + */ + return rounddown_pow_of_two(xfs_calc_max_atomic_write_fsblocks(mp)); +} + +/* * Free all CoW staging blocks that are still referenced by the ondisk refcount * metadata. The ondisk metadata does not track which inode created the * staging extent, so callers must ensure that there are no cached inodes with |