linux.git/fs/btrfs/compression.c, branch v5.10.258

btrfs: mark compressed range uptodate only if all bio succeed

2021-08-04T10:46:39+00:00

commit 240246f6b913b0c23733cfd2def1d283f8cc9bbe upstream.

In compression write endio sequence, the range which the compressed_bio
writes is marked as uptodate if the last bio of the compressed (sub)bios
is completed successfully. There could be previous bio which may
have failed which is recorded in cb->errors.

Set the writeback range as uptodate only if cb->errors is zero, as opposed
to checking only the last bio's status.

Backporting notes: in all versions up to 4.4 the last argument is always
replaced by "!cb->errors".

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Goldwyn Rodrigues 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: handle remount to no compress during compression

2021-05-11T12:47:15+00:00

commit 1d8ba9e7e785b6625f4d8e978e8a284b144a7077 upstream.

[BUG]
When running btrfs/071 with inode_need_compress() removed from
compress_file_range(), we got the following crash:

  BUG: kernel NULL pointer dereference, address: 0000000000000018
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  Workqueue: btrfs-delalloc btrfs_work_helper [btrfs]
  RIP: 0010:compress_file_range+0x476/0x7b0 [btrfs]
  Call Trace:
   ? submit_compressed_extents+0x450/0x450 [btrfs]
   async_cow_start+0x16/0x40 [btrfs]
   btrfs_work_helper+0xf2/0x3e0 [btrfs]
   process_one_work+0x278/0x5e0
   worker_thread+0x55/0x400
   ? process_one_work+0x5e0/0x5e0
   kthread+0x168/0x190
   ? kthread_create_worker_on_cpu+0x70/0x70
   ret_from_fork+0x22/0x30
  ---[ end trace 65faf4eae941fa7d ]---

This is already after the patch "btrfs: inode: fix NULL pointer
dereference if inode doesn't need compression."

[CAUSE]
@pages is firstly created by kcalloc() in compress_file_extent():
                pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);

Then passed to btrfs_compress_pages() to be utilized there:

                ret = btrfs_compress_pages(...
                                           pages,
                                           &nr_pages,
                                           ...);

btrfs_compress_pages() will initialize each page as output, in
zlib_compress_pages() we have:

                        pages[nr_pages] = out_page;
                        nr_pages++;

Normally this is completely fine, but there is a special case which
is in btrfs_compress_pages() itself:

        switch (type) {
        default:
                return -E2BIG;
        }

In this case, we didn't modify @pages nor @out_pages, leaving them
untouched, then when we cleanup pages, the we can hit NULL pointer
dereference again:

        if (pages) {
                for (i = 0; i < nr_pages; i++) {
                        WARN_ON(pages[i]->mapping);
                        put_page(pages[i]);
                }
        ...
        }

Since pages[i] are all initialized to zero, and btrfs_compress_pages()
doesn't change them at all, accessing pages[i]->mapping would lead to
NULL pointer dereference.

This is not possible for current kernel, as we check
inode_need_compress() before doing pages allocation.
But if we're going to remove that inode_need_compress() in
compress_file_extent(), then it's going to be a problem.

[FIX]
When btrfs_compress_pages() hits its default case, modify @out_pages to
0 to prevent such problem from happening.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=212331
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Josef Bacik 
Signed-off-by: Qu Wenruo 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: compression: move declarations to header

2020-10-07T10:06:55+00:00

The declarations of compression algorithm callbacks are defined in the
.c file as they're used from there. Compiler warns that there are no
declarations for public functions when compiling lzo.c/zlib.c/zstd.c.
Fix that by moving the declarations to the header as it's the common
place for all of them.

Reviewed-by: Josef Bacik 
Signed-off-by: David Sterba

btrfs: remove fail label in check_compressed_csum

2020-07-27T10:55:42+00:00

Signed-off-by: Nikolay Borisov 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: increment corrupt device counter during compressed read

2020-07-27T10:55:40+00:00

If a compressed read fails due to checksum error only a line is printed
to dmesg, device corrupt counter is not modified.

Reviewed-by: Josef Bacik 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Nikolay Borisov 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: remove needless ASSERT check of orig_bio in end_compressed_bio_read

2020-07-27T10:55:40+00:00

compressed_bio::orig_bio is always set in btrfs_submit_compressed_read
before any bio submission is performed. Since that function is always
called with a valid bio it renders the ASSERT unnecessary.

Reviewed-by: Josef Bacik 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Nikolay Borisov 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: make btrfs_submit_compressed_write take btrfs_inode

2020-07-27T10:55:31+00:00

Majority of its uses are for btrfs_inode so take it as an argument
directly.

Signed-off-by: Nikolay Borisov 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: make btrfs_csum_one_bio takae btrfs_inode

2020-07-27T10:55:26+00:00

Will enable converting btrfs_submit_compressed_write to btrfs_inode more
easily.

Signed-off-by: Nikolay Borisov 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: unexport btrfs_compress_set_level()

2020-05-25T09:25:37+00:00

btrfs_compress_set_level() can be static function in the file
compression.c.

Reviewed-by: Johannes Thumshirn 
Signed-off-by: Anand Jain 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: use crypto_shash_digest() instead of open coding

2020-05-25T09:25:27+00:00

Use crypto_shash_digest() instead of crypto_shash_init() +
crypto_shash_update() + crypto_shash_final().  This is more efficient.

Signed-off-by: Eric Biggers 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba