diff options
Diffstat (limited to 'fs/xfs/xfs_aops.c')
-rw-r--r-- | fs/xfs/xfs_aops.c | 90 |
1 files changed, 83 insertions, 7 deletions
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 2f4a15e..0e2a931 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -40,6 +40,7 @@ /* flags for direct write completions */ #define XFS_DIO_FLAG_UNWRITTEN (1 << 0) #define XFS_DIO_FLAG_APPEND (1 << 1) +#define XFS_DIO_FLAG_COW (1 << 2) /* * structure owned by writepages passed to individual writepage calls @@ -1190,18 +1191,24 @@ xfs_map_direct( struct inode *inode, struct buffer_head *bh_result, struct xfs_bmbt_irec *imap, - xfs_off_t offset) + xfs_off_t offset, + bool is_cow) { uintptr_t *flags = (uintptr_t *)&bh_result->b_private; xfs_off_t size = bh_result->b_size; trace_xfs_get_blocks_map_direct(XFS_I(inode), offset, size, - ISUNWRITTEN(imap) ? XFS_IO_UNWRITTEN : XFS_IO_OVERWRITE, imap); + ISUNWRITTEN(imap) ? XFS_IO_UNWRITTEN : is_cow ? XFS_IO_COW : + XFS_IO_OVERWRITE, imap); if (ISUNWRITTEN(imap)) { *flags |= XFS_DIO_FLAG_UNWRITTEN; set_buffer_defer_completion(bh_result); - } else if (offset + size > i_size_read(inode) || offset + size < 0) { + } else if (is_cow) { + *flags |= XFS_DIO_FLAG_COW; + set_buffer_defer_completion(bh_result); + } + if (offset + size > i_size_read(inode) || offset + size < 0) { *flags |= XFS_DIO_FLAG_APPEND; set_buffer_defer_completion(bh_result); } @@ -1247,6 +1254,44 @@ xfs_map_trim_size( bh_result->b_size = mapping_size; } +/* Bounce unaligned directio writes to the page cache. */ +static int +xfs_bounce_unaligned_dio_write( + struct xfs_inode *ip, + xfs_fileoff_t offset_fsb, + struct xfs_bmbt_irec *imap) +{ + struct xfs_bmbt_irec irec; + xfs_fileoff_t delta; + bool shared; + bool x; + int error; + + irec = *imap; + if (offset_fsb > irec.br_startoff) { + delta = offset_fsb - irec.br_startoff; + irec.br_blockcount -= delta; + irec.br_startblock += delta; + irec.br_startoff = offset_fsb; + } + error = xfs_reflink_trim_around_shared(ip, &irec, &shared, &x); + if (error) + return error; + + /* + * We're here because we're trying to do a directio write to a + * region that isn't aligned to a filesystem block. If any part + * of the extent is shared, fall back to buffered mode to handle + * the RMW. This is done by returning -EREMCHG ("remote addr + * changed"), which is caught further up the call stack. + */ + if (shared) { + trace_xfs_reflink_bounce_dio_write(ip, imap); + return -EREMCHG; + } + return 0; +} + STATIC int __xfs_get_blocks( struct inode *inode, @@ -1266,6 +1311,8 @@ __xfs_get_blocks( xfs_off_t offset; ssize_t size; int new = 0; + bool is_cow = false; + bool need_alloc = false; BUG_ON(create && !direct); @@ -1291,8 +1338,26 @@ __xfs_get_blocks( end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + size); offset_fsb = XFS_B_TO_FSBT(mp, offset); - error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, - &imap, &nimaps, XFS_BMAPI_ENTIRE); + if (create && direct && xfs_is_reflink_inode(ip)) + is_cow = xfs_reflink_find_cow_mapping(ip, offset, &imap, + &need_alloc); + if (!is_cow) { + error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, + &imap, &nimaps, XFS_BMAPI_ENTIRE); + /* + * Truncate an overwrite extent if there's a pending CoW + * reservation before the end of this extent. This + * forces us to come back to get_blocks to take care of + * the CoW. + */ + if (create && direct && nimaps && + imap.br_startblock != HOLESTARTBLOCK && + imap.br_startblock != DELAYSTARTBLOCK && + !ISUNWRITTEN(&imap)) + xfs_reflink_trim_irec_to_next_cow(ip, offset_fsb, + &imap); + } + ASSERT(!need_alloc); if (error) goto out_unlock; @@ -1344,6 +1409,13 @@ __xfs_get_blocks( if (imap.br_startblock != HOLESTARTBLOCK && imap.br_startblock != DELAYSTARTBLOCK && (create || !ISUNWRITTEN(&imap))) { + if (create && direct && !is_cow) { + error = xfs_bounce_unaligned_dio_write(ip, offset_fsb, + &imap); + if (error) + return error; + } + xfs_map_buffer(inode, bh_result, &imap, offset); if (ISUNWRITTEN(&imap)) set_buffer_unwritten(bh_result); @@ -1352,7 +1424,8 @@ __xfs_get_blocks( if (dax_fault) ASSERT(!ISUNWRITTEN(&imap)); else - xfs_map_direct(inode, bh_result, &imap, offset); + xfs_map_direct(inode, bh_result, &imap, offset, + is_cow); } } @@ -1478,7 +1551,10 @@ xfs_end_io_direct_write( trace_xfs_end_io_direct_write_unwritten(ip, offset, size); error = xfs_iomap_write_unwritten(ip, offset, size); - } else if (flags & XFS_DIO_FLAG_APPEND) { + } + if (flags & XFS_DIO_FLAG_COW) + error = xfs_reflink_end_cow(ip, offset, size); + if (flags & XFS_DIO_FLAG_APPEND) { trace_xfs_end_io_direct_write_append(ip, offset, size); error = xfs_setfilesize(ip, offset, size); |