diff options
Diffstat (limited to 'fs/ext4/inode.c')
-rw-r--r-- | fs/ext4/inode.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 558a585c5df5..6af572425596 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3859,7 +3859,11 @@ int ext4_can_truncate(struct inode *inode) * We have to make sure i_disksize gets properly updated before we truncate * page cache due to hole punching or zero range. Otherwise i_disksize update * can get lost as it may have been postponed to submission of writeback but - * that will never happen after we truncate page cache. + * that will never happen if we remove the folio containing i_size from the + * page cache. Also if we punch hole within i_size but above i_disksize, + * following ext4_page_mkwrite() may mistakenly allocate written blocks over + * the hole and thus introduce allocated blocks beyond i_disksize which is + * not allowed (e2fsck would complain in case of crash). */ int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset, loff_t len) @@ -3870,9 +3874,11 @@ int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset, loff_t size = i_size_read(inode); WARN_ON(!inode_is_locked(inode)); - if (offset > size || offset + len < size) + if (offset > size) return 0; + if (offset + len < size) + size = offset + len; if (EXT4_I(inode)->i_disksize >= size) return 0; |