diff options
| -rw-r--r-- | fs/xfs/xfs_aops.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index e0a793113ea9..0479c32c5eb1 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -1344,6 +1344,14 @@ __xfs_get_blocks( /* * If this is O_DIRECT or the mpage code calling tell them how large * the mapping is, so that we can avoid repeated get_blocks calls. + * + * If the mapping spans EOF, then we have to break the mapping up as the + * mapping for blocks beyond EOF must be marked new so that sub block + * regions can be correctly zeroed. We can't do this for mappings within + * EOF unless the mapping was just allocated or is unwritten, otherwise + * the callers would overwrite existing data with zeros. Hence we have + * to split the mapping into a range up to and including EOF, and a + * second mapping for beyond EOF. */ if (direct || size > (1 << inode->i_blkbits)) { xfs_off_t mapping_size; @@ -1354,6 +1362,12 @@ __xfs_get_blocks( ASSERT(mapping_size > 0); if (mapping_size > size) mapping_size = size; + if (offset < i_size_read(inode) && + offset + mapping_size >= i_size_read(inode)) { + /* limit mapping to block that spans EOF */ + mapping_size = roundup_64(i_size_read(inode) - offset, + 1 << inode->i_blkbits); + } if (mapping_size > LONG_MAX) mapping_size = LONG_MAX; |