btrfs: locking: use atomic for DREW lock writers

The DREW lock uses percpu variable to track lock counters and for that
it needs to allocate the structure. In btrfs_read_tree_root() or
btrfs_init_fs

btrfs: locking: use atomic for DREW lock writers

The DREW lock uses percpu variable to track lock counters and for that
it needs to allocate the structure. In btrfs_read_tree_root() or
btrfs_init_fs_root() this may add another error case or requires the
NOFS scope protection.

One way is to preallocate the structure as was suggested in
https://lore.kernel.org/linux-btrfs/20221214021125.28289-1-robbieko@synology.com/

We may avoid the allocation altogether if we don't use the percpu
variables but an atomic for the writer counter. This should not make any
difference, the DREW lock is used for truncate and NOCOW writes along
with other IO operations.

The percpu counter for writers has been there since the original commit
8257b2dc3c1a1057 "Btrfs: introduce btrfs_{start, end}_nocow_write() for
each subvolume". The reason could be to avoid hammering the same
cacheline from all the readers but then the writers do that anyway.

Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: remove redundant clearing of NODISCARD

If no discard mount option is specified, including the NODISCARD option,
we make the async discard the default option then we don't have to call
the cle

btrfs: remove redundant clearing of NODISCARD

If no discard mount option is specified, including the NODISCARD option,
we make the async discard the default option then we don't have to call
the clear_opt again to clear the NODISCARD flag. Though this makes no
difference, that the call is redundant has been pointed out several
times so we better remove it.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: open_ctree() error handling cleanup

Currently open_ctree() still uses two variables for error handling, err
and ret. This can be confusing and missing some errors and does not
conform to curr

btrfs: open_ctree() error handling cleanup

Currently open_ctree() still uses two variables for error handling, err
and ret. This can be confusing and missing some errors and does not
conform to current coding style.

This patch will fix the problems by:

- Use only ret for error handling

- Add proper ret assignment
Originally we rely on the default value (-EINVAL) of err to handle
errors, but that doesn't really reflects the error.
This will change it use the correct error number for the following
call sites:

* subpage_info allocation
* btrfs_free_extra_devids()
* btrfs_check_rw_degradable()
* cleaner_kthread allocation
* transaction_kthread allocation

- Add an extra ASSERT()
To make sure we error out instead of returning 0.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: move all btree inode initialization into btrfs_init_btree_inode

Move the remaining code that deals with initializing the btree
inode into btrfs_init_btree_inode instead of splitting it betwee

btrfs: move all btree inode initialization into btrfs_init_btree_inode

Move the remaining code that deals with initializing the btree
inode into btrfs_init_btree_inode instead of splitting it between
that helpers and its only caller.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: drop root refs properly when orphan cleanup fails

When we mount the file system we do something like this:

while (1) {
lookup fs roots;

for (i = 0; i < num_roots; i++) {
ret = btrfs

btrfs: drop root refs properly when orphan cleanup fails

When we mount the file system we do something like this:

while (1) {
lookup fs roots;

for (i = 0; i < num_roots; i++) {
ret = btrfs_orphan_cleanup(roots[i]);
if (ret)
break;
btrfs_put_root(roots[i]);
}
}

for (; i < num_roots; i++)
btrfs_put_root(roots[i]);

As you can see if we break in that inner loop we just go back to the
outer loop and lose the fact that we have to drop references on the
remaining roots we looked up. Fix this by making an out label and
jumping to that on error so we don't leak a reference to the roots we
looked up.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: fix fast csum implementation detection

The BTRFS_FS_CSUM_IMPL_FAST flag is currently set whenever a non-generic
crc32c is detected, which is the incorrect check if the file system uses
a diff

btrfs: fix fast csum implementation detection

The BTRFS_FS_CSUM_IMPL_FAST flag is currently set whenever a non-generic
crc32c is detected, which is the incorrect check if the file system uses
a different checksumming algorithm. Refactor the code to only check
this if crc32c is actually used. Note that in an ideal world the
information if an algorithm is hardware accelerated or not should be
provided by the crypto API instead, but that's left for another day.

CC: stable@vger.kernel.org # 5.4.x: c8a5f8ca9a9c: btrfs: print checksum type and implementation at mount time
CC: stable@vger.kernel.org # 5.4.x
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: combine btrfs_clear_buffer_dirty and clear_extent_buffer_dirty

btrfs_clear_buffer_dirty just does the test_clear_bit() and then calls
clear_extent_buffer_dirty and does the dirty metadata acc

btrfs: combine btrfs_clear_buffer_dirty and clear_extent_buffer_dirty

btrfs_clear_buffer_dirty just does the test_clear_bit() and then calls
clear_extent_buffer_dirty and does the dirty metadata accounting.
Combine this into clear_extent_buffer_dirty and make the result
btrfs_clear_buffer_dirty.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: rename btrfs_clean_tree_block to btrfs_clear_buffer_dirty

btrfs_clean_tree_block is a misnomer, it's just
clear_extent_buffer_dirty with some extra accounting around it. Rename
this to btrfs

btrfs: rename btrfs_clean_tree_block to btrfs_clear_buffer_dirty

btrfs_clean_tree_block is a misnomer, it's just
clear_extent_buffer_dirty with some extra accounting around it. Rename
this to btrfs_clear_buffer_dirty to make it more clear it belongs with
it's setter, btrfs_mark_buffer_dirty.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: replace clearing extent buffer dirty bit with btrfs_clean_block

Now that we're passing in the trans into btrfs_clean_tree_block, we can
easily roll in the handling of the !trans case and repl

btrfs: replace clearing extent buffer dirty bit with btrfs_clean_block

Now that we're passing in the trans into btrfs_clean_tree_block, we can
easily roll in the handling of the !trans case and replace all
occurrences of

if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags))
clear_extent_buffer_dirty(eb);

with

btrfs_tree_lock(eb);
btrfs_clean_tree_block(eb);
btrfs_tree_unlock(eb);

We need the lock because if we are actually dirty we need to make sure
we aren't racing with anything that's starting writeout currently. This
also makes sure that we're accounting fs_info->dirty_metadata_bytes
appropriately.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: add trans argument to btrfs_clean_tree_block

We check the header generation in the extent buffer against the current
running transaction id to see if it's safe to clear DIRTY on this
buffer.

btrfs: add trans argument to btrfs_clean_tree_block

We check the header generation in the extent buffer against the current
running transaction id to see if it's safe to clear DIRTY on this
buffer. Generally speaking if we're clearing the buffer dirty we're
holding the transaction open, but in the case of cleaning up an aborted
transaction we don't, so we have extra checks in that path to check the
transid. To allow for a future cleanup go ahead and pass in the trans
handle so we don't have to rely on ->running_transaction being set.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: remove now spurious bio submission helpers

Call btrfs_submit_bio and btrfs_submit_compressed_read directly from
submit_one_bio now that all additional functionality has moved into
btrfs_submi

btrfs: remove now spurious bio submission helpers

Call btrfs_submit_bio and btrfs_submit_compressed_read directly from
submit_one_bio now that all additional functionality has moved into
btrfs_submit_bio.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: remove the fs_info argument to btrfs_submit_bio

btrfs_submit_bio can derive it trivially from bbio->inode, so stop
bothering in the callers.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
R

btrfs: remove the fs_info argument to btrfs_submit_bio

btrfs_submit_bio can derive it trivially from bbio->inode, so stop
bothering in the callers.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: support cloned bios in btree_csum_one_bio

To allow splitting bios in btrfs_submit_bio, btree_csum_one_bio needs to
be able to handle cloned bios. As btree_csum_one_bio is always called
befor

btrfs: support cloned bios in btree_csum_one_bio

To allow splitting bios in btrfs_submit_bio, btree_csum_one_bio needs to
be able to handle cloned bios. As btree_csum_one_bio is always called
before handing the bio to the block layer that is trivially done by using
bio_for_each_segment instead of bio_for_each_segment_all. Also switch
the function to take a btrfs_bio and use that to derive the fs_info.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: handle checksum generation in the storage layer

Instead of letting the callers of btrfs_submit_bio deal with checksumming
the (meta)data in the bio and making decisions on when to offload the

btrfs: handle checksum generation in the storage layer

Instead of letting the callers of btrfs_submit_bio deal with checksumming
the (meta)data in the bio and making decisions on when to offload the
checksumming to the bio, leave that to btrfs_submit_bio. Do do so the
existing btrfs_submit_bio function is split into an upper and a lower
half, so that the lower half can be offloaded to a workqueue.

Note that this changes the behavior for direct writes to raid56 volumes so
that async checksum offloading is not skipped when more I/O is expected.
This runs counter to the argument explaining why it was done, although I
can't measure any affects of the change. Commits later in this series
will make sure the entire direct writes is offloaded to the workqueue
at once and thus make sure it is sent to the raid56 code from a single
thread.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: simplify the btrfs_csum_one_bio calling convention

To prepare for further bio submission changes btrfs_csum_one_bio
should be able to take all it's arguments from the btrfs_bio structure.
It

btrfs: simplify the btrfs_csum_one_bio calling convention

To prepare for further bio submission changes btrfs_csum_one_bio
should be able to take all it's arguments from the btrfs_bio structure.
It can always use the bbio->inode already, and once the compression code
is updated to set ->file_offset that one can be used unconditionally
as well instead of looking at the page mapping now that btrfs doesn't
allow ordered extents to span discontiguous data ranges.

The only slightly tricky bit is the one_ordered flag set by the
compressed writes. Replace that one with the driver private bio
flag, which gets cleared before the bio is handed off to the block layer
so that we don't get in the way of driver use.

Note: this leaves an argument and a flag to btrfs_wq_submit_bio unused.
But that whole mechanism will be removed in its current form in the
next patch.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: open code the submit_bio_start helpers

The submit helpers are now trivial and can be called directly. Note
that btree_csum_one_bio has to be moved up in the file a bit to avoid a
forward dec

btrfs: open code the submit_bio_start helpers

The submit helpers are now trivial and can be called directly. Note
that btree_csum_one_bio has to be moved up in the file a bit to avoid a
forward declaration.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: remove struct btrfs_bio::is_metadata flag

This flag is unused now, so remove it. Re-expand the mirror_num field
to 8 bits, and move it to the I/O completion internal section of the
structure

btrfs: remove struct btrfs_bio::is_metadata flag

This flag is unused now, so remove it. Re-expand the mirror_num field
to 8 bits, and move it to the I/O completion internal section of the
structure.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: fix spelling mistakes found using codespell

There quite a few spelling mistakes as found using codespell. Fix them.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: David

btrfs: fix spelling mistakes found using codespell

There quite a few spelling mistakes as found using codespell. Fix them.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: sysfs: update fs features directory asynchronously

[BUG]
Since the introduction of per-fs feature sysfs interface
(/sys/fs/btrfs/<UUID>/features/), the content of that directory is never
upda

btrfs: sysfs: update fs features directory asynchronously

[BUG]
Since the introduction of per-fs feature sysfs interface
(/sys/fs/btrfs/<UUID>/features/), the content of that directory is never
updated.

Thus for the following case, that directory will not show the new
features like RAID56:

# mkfs.btrfs -f $dev1 $dev2 $dev3
# mount $dev1 $mnt
# btrfs balance start -f -mconvert=raid5 $mnt
# ls /sys/fs/btrfs/$uuid/features/
extended_iref free_space_tree no_holes skinny_metadata

While after unmount and mount, we got the correct features:

# umount $mnt
# mount $dev1 $mnt
# ls /sys/fs/btrfs/$uuid/features/
extended_iref free_space_tree no_holes raid56 skinny_metadata

[CAUSE]
Because we never really try to update the content of per-fs features/
directory.

We had an attempt to update the features directory dynamically in commit
14e46e04958d ("btrfs: synchronize incompat feature bits with sysfs
files"), but unfortunately it get reverted in commit e410e34fad91
("Revert "btrfs: synchronize incompat feature bits with sysfs files"").
The problem in the original patch is, in the context of
btrfs_create_chunk(), we can not afford to update the sysfs group.

The exported but never utilized function, btrfs_sysfs_feature_update()
is the leftover of such attempt. As even if we go sysfs_update_group(),
new files will need extra memory allocation, and we have no way to
specify the sysfs update to go GFP_NOFS.

[FIX]
This patch will address the old problem by doing asynchronous sysfs
update in the cleaner thread.

This involves the following changes:

- Make __btrfs_(set|clear)_fs_(incompat|compat_ro) helpers to set
BTRFS_FS_FEATURE_CHANGED flag when needed

- Update btrfs_sysfs_feature_update() to use sysfs_update_group()
And drop unnecessary arguments.

- Call btrfs_sysfs_feature_update() in cleaner_kthread
If we have the BTRFS_FS_FEATURE_CHANGED flag set.

- Wake up cleaner_kthread in btrfs_commit_transaction if we have
BTRFS_FS_FEATURE_CHANGED flag

By this, all the previously dangerous call sites like
btrfs_create_chunk() need no new changes, as above helpers would
have already set the BTRFS_FS_FEATURE_CHANGED flag.

The real work happens at cleaner_kthread, thus we pay the cost of
delaying the update to sysfs directory, but the delayed time should be
small enough that end user can not distinguish though it might get
delayed if the cleaner thread is busy with removing subvolumes or
defrag.

CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: fix uninitialized variable warning in run_one_async_start

With -Wmaybe-uninitialized compiler complains about ret being possibly
uninitialized, which isn't possible as the WQ_ constants are s

btrfs: fix uninitialized variable warning in run_one_async_start

With -Wmaybe-uninitialized compiler complains about ret being possibly
uninitialized, which isn't possible as the WQ_ constants are set only
from our code, however we can handle the default case and get rid of the
warning.

The value is set to BLK_STS_IOERR so it does not issue any IO and could
be potentially detected, but this is basically a "cannot happen" error.
To catch any problems during development use the assert.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ set the error in default: ]
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: do not abort transaction on failure to write log tree when syncing log

When syncing the log, if we fail to write log tree extent buffers, we mark
the log for a full commit and abort the trans

btrfs: do not abort transaction on failure to write log tree when syncing log

When syncing the log, if we fail to write log tree extent buffers, we mark
the log for a full commit and abort the transaction. However we don't need
to abort the transaction, all we really need to do is to make sure no one
can commit a superblock pointing to new log tree roots. Just because we
got a failure writing extent buffers for a log tree, it does not mean we
will also fail to do a transaction commit.

One particular case is if due to a bug somewhere, when writing log tree
extent buffers, the tree checker detects some corruption and the writeout
fails because of that. Aborting the transaction can be very disruptive for
a user, specially if the issue happened on a root filesystem. One example
is the scenario in the Link tag below, where an isolated corruption on log
tree leaves was causing transaction aborts when syncing the log.

Link: https://lore.kernel.org/linux-btrfs/ae169fc6-f504-28f0-a098-6fa6a4dfb612@leemhuis.info/
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: fix compat_ro checks against remount

[BUG]
Even with commit 81d5d61454c3 ("btrfs: enhance unsupported compat RO
flags handling"), btrfs can still mount a fs with unsupported compat_ro
flags r

btrfs: fix compat_ro checks against remount

[BUG]
Even with commit 81d5d61454c3 ("btrfs: enhance unsupported compat RO
flags handling"), btrfs can still mount a fs with unsupported compat_ro
flags read-only, then remount it RW:

# btrfs ins dump-super /dev/loop0 | grep compat_ro_flags -A 3
compat_ro_flags 0x403
( FREE_SPACE_TREE |
FREE_SPACE_TREE_VALID |
unknown flag: 0x400 )

# mount /dev/loop0 /mnt/btrfs
mount: /mnt/btrfs: wrong fs type, bad option, bad superblock on /dev/loop0, missing codepage or helper program, or other error.
dmesg(1) may have more information after failed mount system call.
^^^ RW mount failed as expected ^^^

# dmesg -t | tail -n5
loop0: detected capacity change from 0 to 1048576
BTRFS: device fsid cb5b82f5-0fdd-4d81-9b4b-78533c324afa devid 1 transid 7 /dev/loop0 scanned by mount (1146)
BTRFS info (device loop0): using crc32c (crc32c-intel) checksum algorithm
BTRFS info (device loop0): using free space tree
BTRFS error (device loop0): cannot mount read-write because of unknown compat_ro features (0x403)
BTRFS error (device loop0): open_ctree failed

# mount /dev/loop0 -o ro /mnt/btrfs
# mount -o remount,rw /mnt/btrfs
^^^ RW remount succeeded unexpectedly ^^^

[CAUSE]
Currently we use btrfs_check_features() to check compat_ro flags against
our current mount flags.

That function get reused between open_ctree() and btrfs_remount().

But for btrfs_remount(), the super block we passed in still has the old
mount flags, thus btrfs_check_features() still believes we're mounting
read-only.

[FIX]
Replace the existing @sb argument with @is_rw_mount.

As originally we only use @sb to determine if the mount is RW.

Now it's callers' responsibility to determine if the mount is RW, and
since there are only two callers, the check is pretty simple:

- caller in open_ctree()
Just pass !sb_rdonly().

- caller in btrfs_remount()
Pass !(*flags & SB_RDONLY), as our check should be against the new
flags.

Now we can correctly reject the RW remount:

# mount /dev/loop0 -o ro /mnt/btrfs
# mount -o remount,rw /mnt/btrfs
mount: /mnt/btrfs: mount point not mounted or bad option.
dmesg(1) may have more information after failed mount system call.
# dmesg -t | tail -n 1
BTRFS error (device loop0: state M): cannot mount read-write because of unknown compat_ro features (0x403)

Reported-by: Chung-Chiang Cheng <shepjeng@gmail.com>
Fixes: 81d5d61454c3 ("btrfs: enhance unsupported compat RO flags handling")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: add error message for metadata level mismatch

From a recent regression report, we found that after commit 947a629988f1
("btrfs: move tree block parentness check into
validate_extent_buffer()"

btrfs: add error message for metadata level mismatch

From a recent regression report, we found that after commit 947a629988f1
("btrfs: move tree block parentness check into
validate_extent_buffer()") if we have a level mismatch (false alert
though), there is no error message at all.

This makes later debugging harder. This patch will add the proper error
message for such case.

Link: https://lore.kernel.org/linux-btrfs/CABXGCsNzVxo4iq-tJSGm_kO1UggHXgq6CdcHDL=z5FL4njYXSQ@mail.gmail.com/
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: move repair_io_failure to bio.c

repair_io_failure ties directly into all the glory low-level details of
mapping a bio with a logic address to the actual physical location.
Move it right below

btrfs: move repair_io_failure to bio.c

repair_io_failure ties directly into all the glory low-level details of
mapping a bio with a logic address to the actual physical location.
Move it right below btrfs_submit_bio to keep all the related logic
together.

Also move btrfs_repair_eb_io_failure to its caller in disk-io.c now that
repair_io_failure is available in a header.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...

btrfs: split the bio submission path into a separate file

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
versio

btrfs: split the bio submission path into a separate file

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 <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

show more ...