linux-stable.git/fs/btrfs/relocation.c, branch linux-6.3.y

btrfs: fix backref walking not returning all inode refs

2023-05-17T12:01:53+00:00

commit 0cad8f14d70cfeb5173dce93cafeba665a95430e upstream.

When using the logical to ino ioctl v2, if the flag to ignore offsets of
file extent items (BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET) is given, the
backref walking code ends up not returning references for all file offsets
of an inode that point to the given logical bytenr. This happens since
kernel 6.2, commit 6ce6ba534418 ("btrfs: use a single argument for extent
offset in backref walking functions") because:

1) It mistakenly skipped the search for file extent items in a leaf that
   point to the target extent if that flag is given. Instead it should
   only skip the filtering done by check_extent_in_eb() - that is, it
   should not avoid the calls to that function (or find_extent_in_eb(),
   which uses it).

2) It was also not building a list of inode extent elements (struct
   extent_inode_elem) if we have multiple inode references for an extent
   when the ignore offset flag is given to the logical to ino ioctl - it
   would leave a single element, only the last one that was found.

These stem from the confusing old interface for backref walking functions
where we had an extent item offset argument that was a pointer to a u64
and another boolean argument that indicated if the offset should be
ignored, but the pointer could be NULL. That NULL case is used by
relocation, qgroup extent accounting and fiemap, simply to avoid building
the inode extent list for each reference, as it's not necessary for those
use cases and therefore avoids memory allocations and some computations.

Fix this by adding a boolean argument to the backref walk context
structure to indicate that the inode extent list should not be built,
make relocation set that argument to true and fix the backref walking
logic to skip the calls to check_extent_in_eb() and find_extent_in_eb()
only if this new argument is true, instead of 'ignore_extent_item_pos'
being true.

A test case for fstests will be added soon, to provide cover not only
for these cases but to the logical to ino ioctl in general as well, as
currently we do not have a test case for it.

Reported-by: Vladimir Panteleev 
Link: https://lore.kernel.org/linux-btrfs/CAHhfkvwo=nmzrJSqZ2qMfF-rZB-ab6ahHnCD_sq9h4o8v+M7QQ@mail.gmail.com/
Fixes: 6ce6ba534418 ("btrfs: use a single argument for extent offset in backref walking functions")
CC: stable@vger.kernel.org # 6.2+
Tested-by: Vladimir Panteleev 
Signed-off-by: Filipe Manana 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: use PAGE_{ALIGN, ALIGNED, ALIGN_DOWN} macro

2023-02-13T16:50:34+00:00

The header file linux/mm.h provides PAGE_ALIGN, PAGE_ALIGNED,
PAGE_ALIGN_DOWN macros. Use these macros to make code more
concise.

Signed-off-by: Yushan Zhou 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: split the bio submission path into a separate file

2022-12-05T17:00:57+00:00

The code used by btrfs_submit_bio only interacts with the rest of
volumes.c through __btrfs_map_block (which itself is a more generic
version of two exported helpers) and does not really have anything
to do with volumes.c.  Create a new bio.c file and a bio.h header
going along with it for the btrfs_bio-based storage layer, which
will grow even more going forward.

Also update the file with my copyright notice given that a large
part of the moved code was written or rewritten by me.

Reviewed-by: Josef Bacik 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Christoph Hellwig 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: introduce a bitmap based csum range search function

2022-12-05T17:00:57+00:00

Although we have an existing function, btrfs_lookup_csums_range(), to
find all data checksums for a range, it's based on a btrfs_ordered_sum
list.

For the incoming RAID56 data checksum verification at RMW time, we don't
want to waste time by allocating temporary memory.

So this patch will introduce a new helper, btrfs_lookup_csums_bitmap().
It will use bitmap based result, which will be a perfect fit for later
RAID56 usage.

Signed-off-by: Qu Wenruo 
Signed-off-by: David Sterba

btrfs: concentrate all tree block parentness check parameters into one structure

2022-12-05T17:00:56+00:00

There are several different tree block parentness check parameters used
across several helpers:

- level
  Mandatory

- transid
  Under most cases it's mandatory, but there are several backref cases
  which skips this check.

- owner_root
- first_key
  Utilized by most top-down tree search routine. Otherwise can be
  skipped.

Those four members are not always mandatory checks, and some of them are
the same u64, which means if some arguments got swapped compiler will
not catch it.

Furthermore if we're going to further expand the parentness check, we
need to modify quite some helpers just to add one more parameter.

This patch will concentrate all these members into a structure called
btrfs_tree_parent_check, and pass that structure for the following
helpers:

- btrfs_read_extent_buffer()
- read_tree_block()

Signed-off-by: Qu Wenruo 
Signed-off-by: David Sterba

btrfs: pass btrfs_inode to btrfs_add_delayed_iput

2022-12-05T17:00:55+00:00

The function is for internal interfaces so we should use the
btrfs_inode.

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

btrfs: drop private_data parameter from extent_io_tree_init

2022-12-05T17:00:54+00:00

All callers except one pass NULL, so the parameter can be dropped and
the inode::io_tree initialization can be open coded.

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

btrfs: pass btrfs_inode to btrfs_inode_unlock

2022-12-05T17:00:53+00:00

The function is for internal interfaces so we should use the
btrfs_inode.

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

btrfs: pass btrfs_inode to btrfs_inode_lock

2022-12-05T17:00:53+00:00

The function is for internal interfaces so we should use the
btrfs_inode.

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

btrfs: use a structure to pass arguments to backref walking functions

2022-12-05T17:00:50+00:00

The public backref walking functions have quite a lot of arguments that
are passed down the call stack to find_parent_nodes(), the core function
of the backref walking code.

The next patches in series will need to add even arguments to these
functions that should be passed not only to find_parent_nodes(), but also
to other functions used by the later (directly or even lower in the call
stack).

So create a structure to hold all these arguments and state used by the
main backref walking function, find_parent_nodes(), and use it as the
argument for the public backref walking functions iterate_extent_inodes(),
btrfs_find_all_leafs() and btrfs_find_all_roots().

Signed-off-by: Filipe Manana 
Signed-off-by: David Sterba