diff options
Diffstat (limited to 'fs/xfs/xfs_reflink.c')
| -rw-r--r-- | fs/xfs/xfs_reflink.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index d953df3..8c3211ce 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -52,6 +52,7 @@ #include "xfs_bmap_btree.h" #include "xfs_reflink.h" #include "xfs_iomap.h" +#include "xfs_rmap_btree.h" /* * Copy on Write of Shared Blocks @@ -412,3 +413,244 @@ xfs_reflink_trim_irec_to_next_cow( return 0; } + +/* + * Cancel all pending CoW reservations for some block range of an inode. + */ +int +xfs_reflink_cancel_cow_blocks( + struct xfs_inode *ip, + struct xfs_trans **tpp, + xfs_fileoff_t offset_fsb, + xfs_fileoff_t end_fsb) +{ + struct xfs_bmbt_irec irec; + xfs_filblks_t count_fsb; + xfs_fsblock_t firstfsb; + struct xfs_defer_ops dfops; + int error = 0; + int nimaps; + + if (!xfs_is_reflink_inode(ip)) + return 0; + + /* Go find the old extent in the CoW fork. */ + while (offset_fsb < end_fsb) { + nimaps = 1; + count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb); + error = xfs_bmapi_read(ip, offset_fsb, count_fsb, &irec, + &nimaps, XFS_BMAPI_COWFORK); + if (error) + break; + ASSERT(nimaps == 1); + + trace_xfs_reflink_cancel_cow(ip, &irec); + + if (irec.br_startblock == DELAYSTARTBLOCK) { + /* Free a delayed allocation. */ + xfs_mod_fdblocks(ip->i_mount, irec.br_blockcount, + false); + ip->i_delayed_blks -= irec.br_blockcount; + + /* Remove the mapping from the CoW fork. */ + error = xfs_bunmapi_cow(ip, &irec); + if (error) + break; + } else if (irec.br_startblock == HOLESTARTBLOCK) { + /* empty */ + } else { + xfs_trans_ijoin(*tpp, ip, 0); + xfs_defer_init(&dfops, &firstfsb); + + xfs_bmap_add_free(ip->i_mount, &dfops, + irec.br_startblock, irec.br_blockcount, + NULL); + + /* Update quota accounting */ + xfs_trans_mod_dquot_byino(*tpp, ip, XFS_TRANS_DQ_BCOUNT, + -(long)irec.br_blockcount); + + /* Roll the transaction */ + error = xfs_defer_finish(tpp, &dfops, ip); + if (error) { + xfs_defer_cancel(&dfops); + break; + } + + /* Remove the mapping from the CoW fork. */ + error = xfs_bunmapi_cow(ip, &irec); + if (error) + break; + } + + /* Roll on... */ + offset_fsb = irec.br_startoff + irec.br_blockcount; + } + + return error; +} + +/* + * Cancel all pending CoW reservations for some byte range of an inode. + */ +int +xfs_reflink_cancel_cow_range( + struct xfs_inode *ip, + xfs_off_t offset, + xfs_off_t count) +{ + struct xfs_trans *tp; + xfs_fileoff_t offset_fsb; + xfs_fileoff_t end_fsb; + int error; + + trace_xfs_reflink_cancel_cow_range(ip, offset, count); + + offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset); + if (count == NULLFILEOFF) + end_fsb = NULLFILEOFF; + else + end_fsb = XFS_B_TO_FSB(ip->i_mount, offset + count); + + /* Start a rolling transaction to remove the mappings */ + error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, + 0, 0, 0, &tp); + if (error) + goto out; + + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, 0); + + /* Scrape out the old CoW reservations */ + error = xfs_reflink_cancel_cow_blocks(ip, &tp, offset_fsb, end_fsb); + if (error) + 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); +out: + trace_xfs_reflink_cancel_cow_range_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) +{ + struct xfs_bmbt_irec irec; + struct xfs_bmbt_irec uirec; + struct xfs_trans *tp; + xfs_fileoff_t offset_fsb; + xfs_fileoff_t end_fsb; + xfs_filblks_t count_fsb; + xfs_fsblock_t firstfsb; + struct xfs_defer_ops dfops; + int error; + unsigned int resblks; + xfs_filblks_t ilen; + xfs_filblks_t rlen; + int nimaps; + + 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); + count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb); + + /* Start a rolling transaction to switch the mappings */ + resblks = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK); + error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, + resblks, 0, 0, &tp); + if (error) + goto out; + + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, 0); + + /* Go find the old extent in the CoW fork. */ + while (offset_fsb < end_fsb) { + /* Read extent from the source file */ + nimaps = 1; + count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb); + error = xfs_bmapi_read(ip, offset_fsb, count_fsb, &irec, + &nimaps, XFS_BMAPI_COWFORK); + if (error) + goto out_cancel; + ASSERT(nimaps == 1); + + ASSERT(irec.br_startblock != DELAYSTARTBLOCK); + trace_xfs_reflink_cow_remap(ip, &irec); + + /* + * We can have a hole in the CoW fork if part of a directio + * write is CoW but part of it isn't. + */ + rlen = ilen = irec.br_blockcount; + if (irec.br_startblock == HOLESTARTBLOCK) + goto next_extent; + + /* Unmap the old blocks in the data fork. */ + while (rlen) { + xfs_defer_init(&dfops, &firstfsb); + error = __xfs_bunmapi(tp, ip, irec.br_startoff, + &rlen, 0, 1, &firstfsb, &dfops); + if (error) + goto out_defer; + + /* + * 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 = irec.br_blockcount - rlen; + irec.br_blockcount = rlen; + trace_xfs_reflink_cow_remap_piece(ip, &uirec); + + /* Map the new blocks into the data fork. */ + error = xfs_bmap_map_extent(tp->t_mountp, &dfops, + ip, &uirec); + if (error) + goto out_defer; + + /* Remove the mapping from the CoW fork. */ + error = xfs_bunmapi_cow(ip, &uirec); + if (error) + goto out_defer; + + error = xfs_defer_finish(&tp, &dfops, ip); + if (error) + goto out_defer; + } + +next_extent: + /* Roll on... */ + offset_fsb = irec.br_startoff + ilen; + } + + error = xfs_trans_commit(tp); + xfs_iunlock(ip, XFS_ILOCK_EXCL); + if (error) + goto out; + return 0; + +out_defer: + xfs_defer_cancel(&dfops); +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; +} |