diff options
Diffstat (limited to 'fs/xfs/xfs_aops.c')
| -rw-r--r-- | fs/xfs/xfs_aops.c | 50 |
1 files changed, 44 insertions, 6 deletions
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 50ab2879b9da..e747d6ad5d18 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -1250,13 +1250,28 @@ xfs_vm_releasepage( * the DIO. There is only going to be one reference to the ioend and its life * cycle is constrained by the DIO completion code. hence we don't need * reference counting here. + * + * Note that for DIO, an IO to the highest supported file block offset (i.e. + * 2^63 - 1FSB bytes) will result in the offset + count overflowing a signed 64 + * bit variable. Hence if we see this overflow, we have to assume that the IO is + * extending the file size. We won't know for sure until IO completion is run + * and the actual max write offset is communicated to the IO completion + * routine. + * + * For DAX page faults, we are preparing to never see unwritten extents here, + * nor should we ever extend the inode size. Hence we will soon have nothing to + * do here for this case, ensuring we don't have to provide an IO completion + * callback to free an ioend that we don't actually need for a fault into the + * page at offset (2^63 - 1FSB) bytes. */ + static void 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 dax_fault) { struct xfs_ioend *ioend; xfs_off_t size = bh_result->b_size; @@ -1269,6 +1284,16 @@ xfs_map_direct( trace_xfs_gbmap_direct(XFS_I(inode), offset, size, type, imap); + /* XXX: preparation for removing unwritten extents in DAX */ +#if 0 + if (dax_fault) { + ASSERT(type == XFS_IO_OVERWRITE); + trace_xfs_gbmap_direct_none(XFS_I(inode), offset, size, type, + imap); + return; + } +#endif + if (bh_result->b_private) { ioend = bh_result->b_private; ASSERT(ioend->io_size > 0); @@ -1283,7 +1308,8 @@ xfs_map_direct( ioend->io_size, ioend->io_type, imap); } else if (type == XFS_IO_UNWRITTEN || - offset + size > i_size_read(inode)) { + offset + size > i_size_read(inode) || + offset + size < 0) { ioend = xfs_alloc_ioend(inode, type); ioend->io_offset = offset; ioend->io_size = size; @@ -1345,7 +1371,8 @@ __xfs_get_blocks( sector_t iblock, struct buffer_head *bh_result, int create, - bool direct) + bool direct, + bool dax_fault) { struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; @@ -1458,7 +1485,8 @@ __xfs_get_blocks( set_buffer_unwritten(bh_result); /* direct IO needs special help */ if (create && direct) - xfs_map_direct(inode, bh_result, &imap, offset); + xfs_map_direct(inode, bh_result, &imap, offset, + dax_fault); } /* @@ -1505,7 +1533,7 @@ xfs_get_blocks( struct buffer_head *bh_result, int create) { - return __xfs_get_blocks(inode, iblock, bh_result, create, false); + return __xfs_get_blocks(inode, iblock, bh_result, create, false, false); } int @@ -1515,7 +1543,17 @@ xfs_get_blocks_direct( struct buffer_head *bh_result, int create) { - return __xfs_get_blocks(inode, iblock, bh_result, create, true); + return __xfs_get_blocks(inode, iblock, bh_result, create, true, false); +} + +int +xfs_get_blocks_dax_fault( + struct inode *inode, + sector_t iblock, + struct buffer_head *bh_result, + int create) +{ + return __xfs_get_blocks(inode, iblock, bh_result, create, true, true); } static void |