linux/fs/ext4/fast_commit.c, branch v6.7

ext4: make state in ext4_mb_mark_bb to be bool

2023-10-06T02:32:15Z

As state could only be either 0 or 1, just make it bool. Signed-off-by: Kemeng Shi Reviewed-by: "Ritesh Harjani (IBM)" Link: https://lore.kernel.org/r/20230928160407.142069-2-shikemeng@huaweicloud.com Signed-off-by: Theodore Ts'o

ext4: use ext4_fc_tl_mem in fast-commit replay path

2023-02-09T15:43:23Z

To avoid 'sparse' warnings about missing endianness conversions, don't store native endianness values into struct ext4_fc_tl. Instead, use a separate struct type, ext4_fc_tl_mem. Fixes: dcc5827484d6 ("ext4: factor out ext4_fc_get_tl()") Cc: Ye Bin Signed-off-by: Eric Biggers Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20221217050212.150665-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o

jbd2: switch jbd2_submit_inode_data() to use fs-provided hook for data writeout

2022-12-09T02:49:25Z

jbd2_submit_inode_data() hardcoded use of jbd2_journal_submit_inode_data_buffers() for submission of data pages. Make it use j_submit_inode_data_buffers hook instead. This effectively switches ext4 fastcommits to use ext4_writepages() for data writeout instead of generic_writepages(). Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20221207112722.22220-9-jack@suse.cz Signed-off-by: Theodore Ts'o

ext4: simplify fast-commit CRC calculation

2022-12-09T02:49:24Z

Instead of checksumming each field as it is added to the block, just checksum each block before it is written. This is simpler, and also much more efficient. Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20221106224841.279231-8-ebiggers@kernel.org Signed-off-by: Theodore Ts'o

ext4: fix off-by-one errors in fast-commit block filling

2022-12-09T02:49:24Z

Due to several different off-by-one errors, or perhaps due to a late change in design that wasn't fully reflected in the code that was actually merged, there are several very strange constraints on how fast-commit blocks are filled with tlv entries: - tlvs must start at least 10 bytes before the end of the block, even though the minimum tlv length is 8. Otherwise, the replay code will ignore them. (BUG: ext4_fc_reserve_space() could violate this requirement if called with a len of blocksize - 9 or blocksize - 8. Fortunately, this doesn't seem to happen currently.) - tlvs must end at least 1 byte before the end of the block. Otherwise the replay code will consider them to be invalid. This quirk contributed to a bug (fixed by an earlier commit) where uninitialized memory was being leaked to disk in the last byte of blocks. Also, strangely these constraints don't apply to the replay code in e2fsprogs, which will accept any tlvs in the blocks (with no bounds checks at all, but that is a separate issue...). Given that this all seems to be a bug, let's fix it by just filling blocks with tlv entries in the natural way. Note that old kernels will be unable to replay fast-commit journals created by kernels that have this commit. Fixes: aa75f4d3daae ("ext4: main fast-commit commit path") Cc: # v5.10+ Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20221106224841.279231-7-ebiggers@kernel.org Signed-off-by: Theodore Ts'o

ext4: fix unaligned memory access in ext4_fc_reserve_space()

2022-12-09T02:49:24Z

As is done elsewhere in the file, build the struct ext4_fc_tl on the stack and memcpy() it into the buffer, rather than directly writing it to a potentially-unaligned location in the buffer. Fixes: aa75f4d3daae ("ext4: main fast-commit commit path") Cc: # v5.10+ Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20221106224841.279231-6-ebiggers@kernel.org Signed-off-by: Theodore Ts'o

ext4: add missing validation of fast-commit record lengths

2022-12-09T02:49:24Z

Validate the inode and filename lengths in fast-commit journal records so that a malicious fast-commit journal cannot cause a crash by having invalid values for these. Also validate EXT4_FC_TAG_DEL_RANGE. Fixes: aa75f4d3daae ("ext4: main fast-commit commit path") Cc: # v5.10+ Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20221106224841.279231-5-ebiggers@kernel.org Signed-off-by: Theodore Ts'o

ext4: fix leaking uninitialized memory in fast-commit journal

2022-12-09T02:49:24Z

When space at the end of fast-commit journal blocks is unused, make sure to zero it out so that uninitialized memory is not leaked to disk. Fixes: aa75f4d3daae ("ext4: main fast-commit commit path") Cc: # v5.10+ Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20221106224841.279231-4-ebiggers@kernel.org Signed-off-by: Theodore Ts'o

ext4: don't set up encryption key during jbd2 transaction

2022-12-09T02:49:24Z

Commit a80f7fcf1867 ("ext4: fixup ext4_fc_track_* functions' signature") extended the scope of the transaction in ext4_unlink() too far, making it include the call to ext4_find_entry(). However, ext4_find_entry() can deadlock when called from within a transaction because it may need to set up the directory's encryption key. Fix this by restoring the transaction to its original scope. Reported-by: syzbot+1a748d0007eeac3ab079@syzkaller.appspotmail.com Fixes: a80f7fcf1867 ("ext4: fixup ext4_fc_track_* functions' signature") Cc: # v5.10+ Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20221106224841.279231-3-ebiggers@kernel.org Signed-off-by: Theodore Ts'o

ext4: disable fast-commit of encrypted dir operations

2022-12-09T02:49:24Z

fast-commit of create, link, and unlink operations in encrypted directories is completely broken because the unencrypted filenames are being written to the fast-commit journal instead of the encrypted filenames. These operations can't be replayed, as encryption keys aren't present at journal replay time. It is also an information leak. Until if/when we can get this working properly, make encrypted directory operations ineligible for fast-commit. Note that fast-commit operations on encrypted regular files continue to be allowed, as they seem to work. Fixes: aa75f4d3daae ("ext4: main fast-commit commit path") Cc: # v5.10+ Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20221106224841.279231-2-ebiggers@kernel.org Signed-off-by: Theodore Ts'o