diff options
| -rw-r--r-- | fs/xfs/xfs_aops.c | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 3e57a56cf829..2693ba84ec25 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -1361,6 +1361,26 @@ __xfs_get_blocks( if (error) goto out_unlock; + /* + * The only time we can ever safely find delalloc blocks on direct I/O + * is a dio write to post-eof speculative preallocation. All other + * scenarios are indicative of a problem or misuse (such as mixing + * direct and mapped I/O). + * + * The file may be unmapped by the time we get here so we cannot + * reliably fail the I/O based on mapping. Instead, fail the I/O if this + * is a read or a write within eof. Otherwise, carry on but warn as a + * precuation if the file happens to be mapped. + */ + if (direct && imap.br_startblock == DELAYSTARTBLOCK) { + if (!create || offset < i_size_read(VFS_I(ip))) { + WARN_ON_ONCE(1); + error = -EIO; + goto out_unlock; + } + WARN_ON_ONCE(mapping_mapped(VFS_I(ip)->i_mapping)); + } + /* for DAX, we convert unwritten extents directly */ if (create && (!nimaps || @@ -1450,8 +1470,6 @@ __xfs_get_blocks( (new || ISUNWRITTEN(&imap)))) set_buffer_new(bh_result); - BUG_ON(direct && imap.br_startblock == DELAYSTARTBLOCK); - return 0; out_unlock: |