kernel.git/include/trace/events/btrfs.h, branch linux-5.12.y

btrfs: add a trace class for dumping the current ENOSPC state

2021-02-08T21:58:59Z

Often when I'm debugging ENOSPC related issues I have to resort to printing the entire ENOSPC state with trace_printk() in different spots. This gets pretty annoying, so add a trace state that does this for us. Then add a trace point at the end of preemptive flushing so you can see the state of the space_info when we decide to exit preemptive flushing. This helped me figure out we weren't kicking in the preemptive flushing soon enough. Reviewed-by: Nikolay Borisov Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: adjust the flush trace point to include the source

2021-02-08T21:58:59Z

Since we have normal ticketed flushing and preemptive flushing, adjust the tracepoint so that we know the source of the flushing action to make it easier to debug problems. Reviewed-by: Nikolay Borisov Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: introduce a FORCE_COMMIT_TRANS flush operation

2021-02-08T21:58:58Z

Solely for preemptive flushing, we want to be able to force the transaction commit without any of the ambiguity of may_commit_transaction(). This is because may_commit_transaction() checks tickets and such, and in preemptive flushing we already know it'll be helpful, so use this to keep the code nice and clean and straightforward. Reviewed-by: Nikolay Borisov Signed-off-by: Josef Bacik [ add comment ] Signed-off-by: David Sterba

btrfs: add a trace point for reserve tickets

2021-02-08T21:58:58Z

While debugging a ENOSPC related performance problem I needed to see the time difference between start and end of a reserve ticket, so add a trace point to report when we handle a reserve ticket. I opted to spit out start_ns itself without calculating the difference because there could be a gap between enabling the tracepoint and setting start_ns. Doing it this way allows us to filter on 0 start_ns so we don't get bogus entries, and we can easily calculate the time difference with bpftrace or something else. Reviewed-by: Nikolay Borisov Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: rework the order of btrfs_ordered_extent::flags

2021-02-08T21:58:52Z

[BUG] There is a long existing bug in the last parameter of btrfs_add_ordered_extent(), in commit 771ed689d2cd ("Btrfs: Optimize compressed writeback and reads") back to 2008. In that ancient commit btrfs_add_ordered_extent() expects the @type parameter to be one of the following: - BTRFS_ORDERED_REGULAR - BTRFS_ORDERED_NOCOW - BTRFS_ORDERED_PREALLOC - BTRFS_ORDERED_COMPRESSED But we pass 0 in cow_file_range(), which means BTRFS_ORDERED_IO_DONE. Ironically extra check in __btrfs_add_ordered_extent() won't set the bit if we see (type == IO_DONE || type == IO_COMPLETE), and avoid any obvious bug. But this still leads to regular COW ordered extent having no bit to indicate its type in various trace events, rendering REGULAR bit useless. [FIX] Change the following aspects to avoid such problem: - Reorder btrfs_ordered_extent::flags Now the type bits go first (REGULAR/NOCOW/PREALLCO/COMPRESSED), then DIRECT bit, finally extra status bits like IO_DONE/COMPLETE/IOERR. - Add extra ASSERT() for btrfs_add_ordered_extent_*() - Remove @type parameter for btrfs_add_ordered_extent_compress() As the only valid @type here is BTRFS_ORDERED_COMPRESSED. - Remove the unnecessary special check for IO_DONE/COMPLETE in __btrfs_add_ordered_extent() This is just to make the code work, with extra ASSERT(), there are limited values can be passed in. Reviewed-by: Nikolay Borisov Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: use own btree inode io_tree owner id

2020-10-07T10:13:22Z

Btree inode is special compared to all other inode extent io_trees, although it has a btrfs inode, it doesn't have the track_uptodate bit at all. This means a lot of things like extent locking doesn't even need to be applied to btree io tree. Since it's so special, adds a new owner value for it to make debuging a little easier. Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: make ordered extent tracepoint take btrfs_inode

2020-10-07T10:12:17Z

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

btrfs: tracepoints: output proper root owner for trace_find_free_extent()

2020-10-07T10:06:49Z

The current trace event always output result like this: find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=4(METADATA) find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=4(METADATA) find_free_extent: root=2(EXTENT_TREE) len=8192 empty_size=0 flags=1(DATA) find_free_extent: root=2(EXTENT_TREE) len=8192 empty_size=0 flags=1(DATA) find_free_extent: root=2(EXTENT_TREE) len=4096 empty_size=0 flags=1(DATA) find_free_extent: root=2(EXTENT_TREE) len=4096 empty_size=0 flags=1(DATA) T's saying we're allocating data extent for EXTENT tree, which is not even possible. It's because we always use EXTENT tree as the owner for trace_find_free_extent() without using the @root from btrfs_reserve_extent(). This patch will change the parameter to use proper @root for trace_find_free_extent(): Now it looks much better: find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) find_free_extent: root=5(FS_TREE) len=8192 empty_size=0 flags=1(DATA) find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=1(DATA) find_free_extent: root=5(FS_TREE) len=4096 empty_size=0 flags=1(DATA) find_free_extent: root=5(FS_TREE) len=8192 empty_size=0 flags=1(DATA) find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) find_free_extent: root=7(CSUM_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) find_free_extent: root=1(ROOT_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) Reported-by: Hans van Kranenburg CC: stable@vger.kernel.org # 5.4+ Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: tracepoints: convert flush states to using EM macros

2020-07-27T10:55:30Z

Only 6 out of all flush states were being printed correctly since only they were exported via the TRACE_DEFINE_ENUM macro. This patch converts all flush states to use the newly introduced EM macro so that they can all be printed correctly. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba

btrfs: tracepoints: switch extent_io_tree_owner to using EM macro

2020-07-27T10:55:30Z

This fixes correct pint out of the extent io tree owner in btrfs_set_extent_bit/btrfs_clear_extent_bit/btrfs_convert_extent_bit tracepoints. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba