linux-stable.git/fs/btrfs/compression.c, branch linux-6.2.y

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: constify input buffer parameter in compression code

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

The input buffers passed down to compression must never be changed,
switch type to u8 as it's a raw byte buffer and use const.

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

btrfs: pass btrfs_inode to btrfs_check_data_csum

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_repair_one_sector

2022-12-05T17:00:52+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: change how repair action is passed to btrfs_repair_one_sector

2022-12-05T17:00:51+00:00

There's a function pointer passed to btrfs_repair_one_sector that will
submit the right bio for repair. However there are only two callbacks,
for buffered and for direct IO. This can be simplified to a bool-based
switch and call either function, indirect calls in this case is an
unnecessary abstraction. This allows to remove the submit_bio_hook_t
typedef.

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

btrfs: move super_block specific helpers into super.h

2022-12-05T17:00:47+00:00

This will make syncing fs.h to user space a little easier if we can pull
the super block specific helpers out of fs.h and put them in super.h.

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

btrfs: move file-item prototypes into their own header

2022-12-05T17:00:46+00:00

Move these prototypes out of ctree.h and into file-item.h.

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

btrfs: move BTRFS_FS_STATE* definitions and helpers to fs.h

2022-12-05T17:00:42+00:00

We're going to use fs.h to hold fs wide related helpers and definitions,
move the FS_STATE enum and related helpers to fs.h, and then update all
files that need these definitions to include fs.h.

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

btrfs: make module init/exit match their sequence

2022-12-05T17:00:40+00:00

[BACKGROUND]
In theory init_btrfs_fs() and exit_btrfs_fs() should match their
sequence, thus normally they should look like this:

    init_btrfs_fs()   |   exit_btrfs_fs()
----------------------+------------------------
    init_A();         |
    init_B();         |
    init_C();         |
                      |   exit_C();
                      |   exit_B();
                      |   exit_A();

So is for the error path of init_btrfs_fs().

But it's not the case, some exit functions don't match their init
functions sequence in init_btrfs_fs().

Furthermore in init_btrfs_fs(), we need to have a new error label for
each new init function we added.  This is not really expandable,
especially recently we may add several new functions to init_btrfs_fs().

[ENHANCEMENT]
The patch will introduce the following things to enhance the situation:

- struct init_sequence
  Just a wrapper of init and exit function pointers.

  The init function must use int type as return value, thus some init
  functions need to be updated to return 0.

  The exit function can be NULL, as there are some init sequence just
  outputting a message.

- struct mod_init_seq[] array
  This is a const array, recording all the initialization we need to do
  in init_btrfs_fs(), and the order follows the old init_btrfs_fs().

- bool mod_init_result[] array
  This is a bool array, recording if we have initialized one entry in
  mod_init_seq[].

  The reason to split mod_init_seq[] and mod_init_result[] is to avoid
  section mismatch in reference.

  All init function are in .init.text, but if mod_init_seq[] records
  the @initialized member it can no longer be const, thus will be put
  into .data section, and cause modpost warning.

For init_btrfs_fs() we just call all init functions in their order in
mod_init_seq[] array, and after each call, setting corresponding
mod_init_result[] to true.

For exit_btrfs_fs() and error handling path of init_btrfs_fs(), we just
iterate mod_init_seq[] in reverse order, and skip all uninitialized
entry.

With this patch, init_btrfs_fs()/exit_btrfs_fs() will be much easier to
expand and will always follow the strict order.

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

fs: fix leaked psi pressure state

2022-11-08T23:57:25+00:00

When psi annotations were added to to btrfs compression reads, the psi
state tracking over add_ra_bio_pages and btrfs_submit_compressed_read was
faulty.  A pressure state, once entered, is never left.  This results in
incorrectly elevated pressure, which triggers OOM kills.

pflags record the *previous* memstall state when we enter a new one.  The
code tried to initialize pflags to 1, and then optimize the leave call
when we either didn't enter a memstall, or were already inside a nested
stall.  However, there can be multiple PageWorkingset pages in the bio, at
which point it's that path itself that enters repeatedly and overwrites
pflags.  This causes us to miss the exit.

Enter the stall only once if needed, then unwind correctly.

erofs has the same problem, fix that up too.  And move the memstall exit
past submit_bio() to restore submit accounting originally added by
b8e24a9300b0 ("block: annotate refault stalls from IO submission").

Link: https://lkml.kernel.org/r/Y2UHRqthNUwuIQGS@cmpxchg.org
Fixes: 4088a47e78f9 ("btrfs: add manual PSI accounting for compressed reads")
Fixes: 99486c511f68 ("erofs: add manual PSI accounting for the compressed address space")
Fixes: 118f3663fbc6 ("block: remove PSI accounting from the bio layer")
Link: https://lore.kernel.org/r/d20a0a85-e415-cf78-27f9-77dd7a94bc8d@leemhuis.info/
Signed-off-by: Johannes Weiner 
Reported-by: Thorsten Leemhuis 
Tested-by: Thorsten Leemhuis 
Cc: Chao Yu 
Cc: Chris Mason 
Cc: Christoph Hellwig 
Cc: David Sterba 
Cc: Gao Xiang 
Cc: Jens Axboe 
Cc: Josef Bacik 
Cc: Suren Baghdasaryan 
Signed-off-by: Andrew Morton