linux.git/fs/btrfs/tests, branch v6.0

btrfs: add optimized btrfs_ino() version for 64 bits systems

2022-07-25T15:45:41+00:00

Currently btrfs_ino() tries to use first the objectid of the inode's
location key. This is to avoid truncation of the inode number on 32 bits
platforms because the i_ino field of struct inode has the unsigned long
type, while the objectid is a 64 bits unsigned type (u64) on every system.
This logic was added in commit 33345d01522f81 ("Btrfs: Always use 64bit
inode number").

However if we are running on a 64 bits system, we can always directly
return the i_ino value from struct inode, which eliminates the need for
he special if statement that tests for a location key type of
BTRFS_ROOT_ITEM_KEY - in which case i_ino may not have the same value as
the objectid in the inode's location objectid, it may have a value of
BTRFS_EMPTY_SUBVOL_DIR_OBJECTID, for the case of snapshots of trees with
subvolumes/snapshots inside them.

So add a special version for 64 bits system that directly returns i_ino
of struct inode. This eliminates one branch and reduces the overall code
size, since btrfs_ino() is an inline function that is extensively used.

Before:

$ size fs/btrfs/btrfs.ko
   text	   data	    bss	    dec	    hex	filename
1617487	 189240	  29032	1835759	 1c02ef	fs/btrfs/btrfs.ko

After:

$ size fs/btrfs/btrfs.ko
   text	   data	    bss	    dec	    hex	filename
1612028	 189180	  29032	1830240	 1bed60	fs/btrfs/btrfs.ko

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

btrfs: clean up chained assignments

2022-07-25T15:45:39+00:00

The chained assignments may be convenient to write, but make readability
a bit worse as it's too easy to overlook that there are several values
set on the same line while this is rather an exception.  Making it
consistent everywhere avoids surprises.

The pattern where inode times are initialized reuses the first value and
the order is mtime, ctime. In other blocks the assignments are expanded
so the order of variables is similar to the neighboring code.

Signed-off-by: David Sterba

Revert "btrfs: turn fs_info member buffer_radix into XArray"

2022-07-15T17:14:33+00:00

This reverts commit 8ee922689d67b7cfa6acbe2aa1ee76ac72e6fc8a.

Revert the xarray conversion, there's a problem with potential
sleep-inside-spinlock [1] when calling xa_insert that triggers GFP_NOFS
allocation. The radix tree used the preloading mechanism to avoid
sleeping but this is not available in xarray.

Conversion from spin lock to mutex is possible but at time of rc6 is
riskier than a clean revert.

[1] https://lore.kernel.org/linux-btrfs/cover.1657097693.git.fdmanana@suse.com/

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

Revert "btrfs: turn fs_roots_radix in btrfs_fs_info into an XArray"

2022-07-15T17:14:28+00:00

This reverts commit 48b36a602a335c184505346b5b37077840660634.

Revert the xarray conversion, there's a problem with potential
sleep-inside-spinlock [1] when calling xa_insert that triggers GFP_NOFS
allocation. The radix tree used the preloading mechanism to avoid
sleeping but this is not available in xarray.

Conversion from spin lock to mutex is possible but at time of rc6 is
riskier than a clean revert.

[1] https://lore.kernel.org/linux-btrfs/cover.1657097693.git.fdmanana@suse.com/

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

btrfs: turn fs_roots_radix in btrfs_fs_info into an XArray

2022-05-16T15:15:57+00:00

… rename it to simply fs_roots and adjust all usages of this object to use
the XArray API, because it is notionally easier to use and understand, as
it provides array semantics, and also takes care of locking for us,
further simplifying the code.

Also do some refactoring, esp. where the API change requires largely
rewriting some functions, anyway.

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

btrfs: turn fs_info member buffer_radix into XArray

2022-05-16T15:03:16+00:00

… named 'extent_buffers'. Also adjust all usages of this object to use
the XArray API, which greatly simplifies the code as it takes care of
locking and is generally easier to use and understand, providing
notionally simpler array semantics.

Also perform some light refactoring.

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

btrfs: assert we have a write lock when removing and replacing extent maps

2022-03-14T12:13:50+00:00

Removing or replacing an extent map requires holding a write lock on the
extent map's tree. We currently do that everywhere, except in one of the
self tests, where it's harmless since there's no concurrency.

In order to catch possible races in the future, assert that we are holding
a write lock on the extent map tree before removing or replacing an extent
map in the tree, and update the self test to obtain a write lock before
removing extent maps.

Reviewed-by: Johannes Thumshirn 
Signed-off-by: Filipe Manana 
Signed-off-by: David Sterba

btrfs: selftests: dump extent io tree if extent-io-tree test failed

2022-01-07T13:18:27+00:00

When code modifying extent-io-tree get modified and got that selftest
failed, it can take some time to pin down the cause.

To make it easier to expose the problem, dump the extent io tree if the
selftest failed.

This can save developers debug time, especially since the selftest we
can not use the trace events, thus have to manually add debug trace
points.

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

btrfs: track the csum, extent, and free space trees in a rb tree

2022-01-03T14:09:50+00:00

In the future we are going to have multiple copies of these trees.  To
facilitate this we need a way to lookup the different roots we are
looking for.  Handle this by adding a global root rb tree that is
indexed on the root->root_key.  Then instead of loading the roots at
mount time with individually targeted keys, simply search the tree_root
for anything with the specific objectid we want.  This will make it
straightforward to support both old style and new style file systems.

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

btrfs: stop accessing ->free_space_root directly

2022-01-03T14:09:49+00:00

We're going to have multiple free space roots in the future, so adjust
all the users of the free space root to use a helper to access the root.

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