- 05 Dec, 2022 40 commits
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Sweet Tea Dorminy authored
Many functions throughout btrfs take name buffer and name length arguments. Most of these functions at the highest level are usually called with these arguments extracted from a supplied dentry's name. But the entire name can be passed instead, making each function a little more elegant. Each function whose arguments are currently the name and length extracted from a dentry is herein converted to instead take a pointer to the name in the dentry. The couple of calls to these calls without a struct dentry are converted to create an appropriate qstr to pass in. Additionally, every function which is only called with a name/len extracted directly from a qstr is also converted. This change has positive effect on stack consumption, frame of many functions is reduced but this will be used in the future for fscrypt related structures. Signed-off-by:
Sweet Tea Dorminy <sweettea-kernel@dorminy.me> Reviewed-by:
David Sterba <dsterba@suse.com> Signed-off-by:
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Anand Jain authored
The module exit function exit_btrfs_fs() is duplicating a section of code in init_btrfs_fs(). Add a helper to remove the duplicated code. Due to the init/exit section requirements the function must be inline and not a plain static as it could cause section mismatch. Signed-off-by:
Anand Jain <anand.jain@oracle.com> Reviewed-by:
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David Sterba authored
All callers pas GFP_KERNEL as parameter so we can use it directly in alloc_scrub_sector. Reviewed-by:
Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by:
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David Sterba authored
There's only one caller that calls scrub_setup_recheck_block in the memalloc_nofs_save/_restore protection so it's effectively already GFP_NOFS and it's safe to use GFP_KERNEL. Reviewed-by:
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David Sterba authored
All callers pass GFP_NOFS, we can drop the parameter and use it directly. Reviewed-by:
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David Sterba authored
There's only one caller that passes GFP_NOFS, we can drop the parameter an use the flags directly. Reviewed-by:
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Josef Bacik authored
This was added while I was moving this code to its new home, it can be removed now. Reviewed-by:
Josef Bacik <josef@toxicpanda.com> Reviewed-by:
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Josef Bacik authored
This is a large patch, but because they're all macros it's impossible to split up. Simply copy all of the item accessors in ctree.h and paste them in accessors.h, and then update any files to include the header so everything compiles. Reviewed-by:
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Josef Bacik authored
This is specific to the item-accessor code, move it out of ctree.h into accessor.h/.c and then update the users to include the new header file. This un-inlines btrfs_init_map_token, however this is only called once per function so it's not critical to be inlined. This also saves 904 bytes of code on a release build. Reviewed-by:
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Josef Bacik authored
Rename struct-funcs.c to accessors.c so we can move the item accessors out of ctree.h. accessors.c is a better description of the code that is contained in these files. Reviewed-by:
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Josef Bacik authored
This is fs wide information, move it out of ctree.h into fs.h. Reviewed-by:
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Josef Bacik authored
Now that we're not using this code anywhere we can remove it as well as the member from fs_info. We don't have any mount options or on/off features that would utilize the pending infrastructure, the last one was inode_cache. There was a patchset [1] to enable some features from sysfs that would break things if it would be set immediately. In case we'll need that kind of logic again the patch can be reverted, but for the current use it can be replaced by the single state bit to do the commit. [1] https://lore.kernel.org/linux-btrfs/1422609654-19519-1-git-send-email-quwenruo@cn.fujitsu.com/Reviewed-by:
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Josef Bacik authored
Currently we are only using fs_info->pending_changes to indicate that we need a transaction commit. The original users for this were removed years ago and we don't have more usage in sight, so this is the only remaining reason to have this field. Add a flag so we can remove this code. Reviewed-by:
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Josef Bacik authored
These definitions are fs wide, take them out of ctree.h and put them in fs.h. Reviewed-by:
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Josef Bacik authored
These are fs wide definitions and helpers, move them out of ctree.h and into fs.h. Reviewed-by:
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Josef Bacik authored
These helpers use functions not defined in fs.h, they're simply accessors of the super block in fs_info, convert them to macros so that we don't have a weird dependency between fs.h and accessors.h. Signed-off-by:
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Josef Bacik authored
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:
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Josef Bacik authored
The printk index work can be pushed into the printk helpers themselves, this allows us to further sanitize messages.h, removing the last include in the header itself. Reviewed-by:
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Josef Bacik authored
We have a bunch of printk helpers that are in ctree.h. These have nothing to do with ctree.c, so move them into their own header. Subsequent patches will cleanup the printk helpers. Reviewed-by:
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Josef Bacik authored
These call functions that aren't defined in, or will be moved out of, ctree.h Move them to super.c where the other assert/error message code is defined. Drop the __noreturn attribute for btrfs_assertfail as objtool does not like it and fails with warnings like fs/btrfs/dir-item.o: warning: objtool: .text.unlikely: unexpected end of section fs/btrfs/xattr.o: warning: objtool: btrfs_setxattr() falls through to next function btrfs_setxattr_trans.cold() fs/btrfs/xattr.o: warning: objtool: .text.unlikely: unexpected end of section Reviewed-by:
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Josef Bacik authored
We have several fs wide related helpers in ctree.h. The bulk of these are the incompat flag test helpers, but there are things such as btrfs_fs_closing() and the read only helpers that also aren't directly related to the ctree code. Move these into a fs.h header, which will serve as the location for file system wide related helpers. Reviewed-by:
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Wang Yugui authored
Add a define for the data buffer size (though the maximum size is not limited by it) BTRFS_SEND_BUF_SIZE_V2 so it's more visible. Signed-off-by:
Wang Yugui <wangyugui@e16-tech.com> Reviewed-by:
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David Sterba authored
Callers that pass non-zero generation always want to perform the generation check, we can simply encode that in one parameter and drop check_generation. Add function documentation. Reviewed-by:
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David Sterba authored
There's a request to automatically enable async discard for capable devices. We can do that, the async mode is designed to wait for larger freed extents and is not intrusive, with limits to iops, kbps or latency. The status and tunables will be exported in /sys/fs/btrfs/FSID/discard . The automatic selection is done if there's at least one discard capable device in the filesystem (not capable devices are skipped). Mounting with any other discard option will honor that option, notably mounting with nodiscard will keep it disabled. Link: https://lore.kernel.org/linux-btrfs/CAEg-Je_b1YtdsCR0zS5XZ_SbvJgN70ezwvRwLiCZgDGLbeMB=w@mail.gmail.com/Reviewed-by:
Boris Burkov <boris@bur.io> Signed-off-by:
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David Sterba authored
The sysfs_emit is the safe API for writing to the sysfs files, previously converted from scnprintf, there's one left to do in btrfs_read_policy_show. Reviewed-by:
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Josef Bacik authored
We sometimes have to allocate new extent states when clearing or setting new bits in an extent io tree. Generally we preallocate this before taking the tree spin lock, but we can use this preallocated extent state sometimes and then need to try to do a GFP_ATOMIC allocation under the lock. Unfortunately sometimes this fails, and then we hit the BUG_ON() and bring the box down. This happens roughly 20 times a week in our fleet. However the vast majority of callers use GFP_NOFS, which means that if this GFP_ATOMIC allocation fails, we could simply drop the spin lock, go back and allocate a new extent state with our given gfp mask, and begin again from where we left off. For the remaining callers that do not use GFP_NOFS, they are generally using GFP_NOWAIT, which still allows for some reclaim. So allow these allocations to attempt to happen outside of the spin lock so we don't need to rely on GFP_ATOMIC allocations. This in essence creates an infinite loop for anything that isn't GFP_NOFS. To address this we may want to migrate to using mempools for extent states so that we will always have emergency reserves in order to make our allocations. Signed-off-by:
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Josef Bacik authored
As of "btrfs: do not use GFP_ATOMIC in the read endio" we no longer have any users of unlock_extent_atomic, remove it. Signed-off-by:
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Josef Bacik authored
We have done read endio in an async thread for a very, very long time, which makes the use of GFP_ATOMIC and unlock_extent_atomic() unneeded in our read endio path. We've noticed under heavy memory pressure in our fleet that we can fail these allocations, and then often trip a BUG_ON(!allocation), which isn't an ideal outcome. Begin to address this by simply not using GFP_ATOMIC, which will allow us to do things like actually allocate a extent state when doing set_extent_bits(UPTODATE) in the endio handler. End io handlers are not called in atomic context, besides we have been allocating failrec with GFP_NOFS so we'd notice there's a problem. Signed-off-by:
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Qu Wenruo authored
[BACKGROUND] When committing a transaction, we will update block group items for all dirty block groups. But in fact, dirty block groups don't always need to update their block group items. It's pretty common to have a metadata block group which experienced several COW operations, but still have the same amount of used bytes. In that case, we may unnecessarily COW a tree block doing nothing. [ENHANCEMENT] This patch will introduce btrfs_block_group::commit_used member to remember the last used bytes, and use that new member to skip unnecessary block group item update. This would be more common for large filesystems, where metadata block group can be as large as 1GiB, containing at most 64K metadata items. In that case, if COW added and then deleted one metadata item near the end of the block group, then it's completely possible we don't need to touch the block group item at all. [BENCHMARK] The change itself can have quite a high chance (20~80%) to skip block group item updates in lot of workloads. As a result, it would result shorter time spent on btrfs_write_dirty_block_groups(), and overall reduce the execution time of the critical section of btrfs_commit_transaction(). Here comes a fio command, which will do random writes in 4K block size, causing a very heavy metadata updates. fio --filename=$mnt/file --size=512M --rw=randwrite --direct=1 --bs=4k \ --ioengine=libaio --iodepth=64 --runtime=300 --numjobs=4 \ --name=random_write --fallocate=none --time_based --fsync_on_close=1 The file size (512M) and number of threads (4) means 2GiB file size in total, but during the full 300s run time, my dedicated SATA SSD is able to write around 20~25GiB, which is over 10 times the file size. Thus after we fill the initial 2G, we should not cause much block group item updates. Please note, the fio numbers by themselves don't have much change, but if we look deeper, there is some reduced execution time, especially for the critical section of btrfs_commit_transaction(). I added extra trace_printk() to measure the following per-transaction execution time: - Critical section of btrfs_commit_transaction() By re-using the existing update_commit_stats() function, which has already calculated the interval correctly. - The while() loop for btrfs_write_dirty_block_groups() Although this includes the execution time of btrfs_run_delayed_refs(), it should still be representative overall. Both result involves transid 7~30, the same amount of transaction committed. The result looks like this: | Before | After | Diff ----------------------+-------------------+----------------+-------- Transaction interval | 229247198.5 | 215016933.6 | -6.2% Block group interval | 23133.33333 | 18970.83333 | -18.0% The change in block group item updates is more obvious, as skipped block group item updates also mean less delayed refs. And the overall execution time for that block group update loop is pretty small, thus we can assume the extent tree is already mostly cached. If we can skip an uncached tree block, it would cause more obvious change. Unfortunately the overall reduction in commit transaction critical section is much smaller, as the block group item updates loop is not really the major part, at least not for the above fio script. But still we have a observable reduction in the critical section. Reviewed-by:Qu Wenruo <wqu@suse.com> Signed-off-by:
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David Sterba authored
The base transaction bits can be defined as bits in a contiguous sequence, although right now there's a hole from bit 1 to 8. The bits are used for btrfs_trans_handle::type, and there's another set of TRANS_STATE_* defines that are for btrfs_transaction::state. They are mutually exclusive though the hole in the sequence looks like was made for the states. Reviewed-by:
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David Sterba authored
The defines/enums are used only for tracepoints and are not part of the on-disk format. Reviewed-by:
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David Sterba authored
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David Sterba authored
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David Sterba authored
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David Sterba authored
Define helper macro that can be used in enum {} to utilize the automatic increment to define all bits without directly defining the values or using additional linear bits. 1. capture the sequence value, N 2. use the value to define the given enum with N-th bit set 3. reset the sequence back to N Use for enums that do not require fixed values for symbolic names (like for on-disk structures): enum { ENUM_BIT(FIRST), ENUM_BIT(SECOND), ENUM_BIT(THIRD) }; Where the values would be 0x1, 0x2 and 0x4. Reviewed-by: -
Qu Wenruo authored
[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: -
Filipe Manana authored
All callers of btrfs_tree_mod_log_insert_key() are now passing a GFP_NOFS flag to it, so remove the flag from it and from alloc_tree_mod_elem() and use it directly within alloc_tree_mod_elem(). Signed-off-by:
Filipe Manana <fdmanana@suse.com> Reviewed-by:
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Filipe Manana authored
When fixing up the first key of each node above the current level, at fixup_low_keys(), we are doing a GFP_ATOMIC allocation for inserting an operation record for the tree mod log. However we can do just fine with GFP_NOFS nowadays. The need for GFP_ATOMIC was for the old days when we had custom locks with spinning behaviour for extent buffers and we were in spinning mode while at fixup_low_keys(). Now we use rw semaphores for extent buffer locks, so we can safely use GFP_NOFS. Signed-off-by:
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Boris Burkov authored
I have observed the following case play out and lead to unnecessary relocations: 1. write a file across multiple block groups 2. delete the file 3. several block groups fall below the reclaim threshold 4. reclaim the first, moving extents into the others 5. reclaim the others which are now actually very full, leading to poor reclaim behavior with lots of writing, allocating new block groups, etc. I believe the risk of missing some reasonable reclaims is worth it when traded off against the savings of avoiding overfull reclaims. Going forward, it could be interesting to make the check more advanced (zoned aware, fragmentation aware, etc...) so that it can be a really strong signal both at extent delete and reclaim time. Reviewed-by:
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Boris Burkov authored
As we delete extents from a block group, at some deletion we cross below the reclaim threshold. It is possible we are still in the middle of deleting more extents and might soon hit 0. If the block group is empty by the time the reclaim worker runs, we will still relocate it. This works just fine, as relocating an empty block group ultimately results in properly deleting it. However, we have more direct ways of removing empty block groups in the cleaner thread. Those are either async discard or the unused_bgs list. In fact, when we decide whether to relocate a block group during extent deletion, we do check for emptiness and prefer the discard/unused_bgs mechanisms when possible. Not using relocation for this case reduces some modest overhead from empty bg relocation: - extra transactions - extra metadata use/churn for creating relocation metadata - trying to read the extent tree to look for extents (and in this case finding none) Reviewed-by:
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