kernel/linux.git/fs/ext4/ext4.h, branch v6.4

ext4: add lockdep annotations for i_data_sem for ea_inode's

2023-05-30T19:33:57+00:00

Treat i_data_sem for ea_inodes as being in their own lockdep class to avoid lockdep complaints about ext4_setattr's use of inode_lock() on normal inodes potentially causing lock ordering with i_data_sem on ea_inodes in ext4_xattr_inode_write(). However, ea_inodes will be operated on by ext4_setattr(), so this isn't a problem. Cc: stable@kernel.org Link: https://syzkaller.appspot.com/bug?extid=298c5d8fb4a128bc27b0 Reported-by: syzbot+298c5d8fb4a128bc27b0@syzkaller.appspotmail.com Signed-off-by: Theodore Ts'o Link: https://lore.kernel.org/r/20230524034951.779531-5-tytso@mit.edu Signed-off-by: Theodore Ts'o

ext4: add EA_INODE checking to ext4_iget()

2023-05-28T18:18:03+00:00

Add a new flag, EXT4_IGET_EA_INODE which indicates whether the inode is expected to have the EA_INODE flag or not. If the flag is not set/clear as expected, then fail the iget() operation and mark the file system as corrupted. This commit also makes the ext4_iget() always perform the is_bad_inode() check even when the inode is already inode cache. This allows us to remove the is_bad_inode() check from the callers of ext4_iget() in the ea_inode code. Reported-by: syzbot+cbb68193bdb95af4340a@syzkaller.appspotmail.com Reported-by: syzbot+62120febbd1ee3c3c860@syzkaller.appspotmail.com Reported-by: syzbot+edce54daffee36421b4c@syzkaller.appspotmail.com Cc: stable@kernel.org Signed-off-by: Theodore Ts'o Link: https://lore.kernel.org/r/20230524034951.779531-2-tytso@mit.edu Signed-off-by: Theodore Ts'o

ext4: avoid deadlock in fs reclaim with page writeback

2023-05-13T22:05:04+00:00

Ext4 has a filesystem wide lock protecting ext4_writepages() calls to avoid races with switching of journalled data flag or inode format. This lock can however cause a deadlock like: CPU0 CPU1 ext4_writepages() percpu_down_read(sbi->s_writepages_rwsem); ext4_change_inode_journal_flag() percpu_down_write(sbi->s_writepages_rwsem); - blocks, all readers block from now on ext4_do_writepages() ext4_init_io_end() kmem_cache_zalloc(io_end_cachep, GFP_KERNEL) fs_reclaim frees dentry... dentry_unlink_inode() iput() - last ref => iput_final() - inode dirty => write_inode_now()... ext4_writepages() tries to acquire sbi->s_writepages_rwsem and blocks forever Make sure we cannot recurse into filesystem reclaim from writeback code to avoid the deadlock. Reported-by: syzbot+6898da502aef574c5f8a@syzkaller.appspotmail.com Link: https://lore.kernel.org/all/0000000000004c66b405fa108e27@google.com Fixes: c8585c6fcaf2 ("ext4: fix races between changing inode journal mode and ext4_writepages") CC: stable@vger.kernel.org Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230504124723.20205-1-jack@suse.cz Signed-off-by: Theodore Ts'o

ext4: allow ext4_get_group_info() to fail

2023-05-13T22:02:46+00:00

Previously, ext4_get_group_info() would treat an invalid group number as BUG(), since in theory it should never happen. However, if a malicious attaker (or fuzzer) modifies the superblock via the block device while it is the file system is mounted, it is possible for s_first_data_block to get set to a very large number. In that case, when calculating the block group of some block number (such as the starting block of a preallocation region), could result in an underflow and very large block group number. Then the BUG_ON check in ext4_get_group_info() would fire, resutling in a denial of service attack that can be triggered by root or someone with write access to the block device. For a quality of implementation perspective, it's best that even if the system administrator does something that they shouldn't, that it will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info() will call ext4_error and return NULL. We also add fallback code in all of the callers of ext4_get_group_info() that it might NULL. Also, since ext4_get_group_info() was already borderline to be an inline function, un-inline it. The results in a next reduction of the compiled text size of ext4 by roughly 2k. Cc: stable@kernel.org Link: https://lore.kernel.org/r/20230430154311.579720-2-tytso@mit.edu Reported-by: syzbot+e2efa3efc15a1c9e95c3@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?id=69b28112e098b070f639efb356393af3ffec4220 Signed-off-by: Theodore Ts'o Reviewed-by: Jan Kara

ext4: Add a uapi header for ext4 userspace APIs

2023-04-20T03:39:42+00:00

Create a uapi header include/uapi/linux/ext4.h, move the ioctls and associated data structures to the uapi header, and include it from fs/ext4/ext4.h. Signed-off-by: Josh Triplett Link: https://lore.kernel.org/r/680175260970d977d16b5cc7e7606483ec99eb63.1680402881.git.josh@joshtriplett.org Signed-off-by: Theodore Ts'o

ext4: Simplify handling of journalled data in ext4_bmap()

2023-04-14T23:58:33+00:00

Now that ext4_writepages() gets journalled data into its final location we just use filemap_write_and_wait() instead of special handling of journalled data in ext4_bmap(). We can also drop EXT4_STATE_JDATA flag as it is not used anymore. Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230329154950.19720-11-jack@suse.cz Signed-off-by: Theodore Ts'o

ext4: Convert ext4_mpage_readpages() to work on folios

2023-04-06T17:39:52+00:00

This definitely doesn't include support for large folios; there are all kinds of assumptions about the number of buffers attached to a folio. But it does remove several calls to compound_head(). Signed-off-by: Matthew Wilcox (Oracle) Link: https://lore.kernel.org/r/20230324180129.1220691-24-willy@infradead.org Signed-off-by: Theodore Ts'o

ext4: Convert ext4_readpage_inline() to take a folio

2023-04-06T17:39:51+00:00

Use the folio API in this function, saves a few calls to compound_head(). Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Theodore Ts'o Link: https://lore.kernel.org/r/20230324180129.1220691-10-willy@infradead.org Signed-off-by: Theodore Ts'o

ext4: Convert ext4_bio_write_page() to ext4_bio_write_folio()

2023-04-06T17:39:51+00:00

The only caller now has a folio so pass it in directly and avoid the call to page_folio() at the beginning. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Theodore Ts'o Link: https://lore.kernel.org/r/20230324180129.1220691-9-willy@infradead.org Signed-off-by: Theodore Ts'o

ext4: Remove the logic to trim inode PAs

2023-04-06T05:13:13+00:00

Earlier, inode PAs were stored in a linked list. This caused a need to periodically trim the list down inorder to avoid growing it to a very large size, as this would severly affect performance during list iteration. Recent patches changed this list to an rbtree, and since the tree scales up much better, we no longer need to have the trim functionality, hence remove it. Signed-off-by: Ojaswin Mujoo Reviewed-by: Ritesh Harjani (IBM) Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/c409addceaa3ade4b40328e28e3b54b2f259689e.1679731817.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o