- 03 Jan, 2022 29 commits
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Josef Bacik authored
Currently we index free space on offset only, because usually we have a hint from the allocator that we want to honor for locality reasons. However if we fail to use this hint we have to go back to a brute force search through the free space entries to find a large enough extent. With sufficiently fragmented free space this becomes quite expensive, as we have to linearly search all of the free space entries to find if we have a part that's long enough. To fix this add a cached rb tree to index based on free space entry bytes. This will allow us to quickly look up the largest chunk in the free space tree for this block group, and stop searching once we've found an entry that is too small to satisfy our allocation. We simply choose to use this tree if we're searching from the beginning of the block group, as we know we do not care about locality at that point. I wrote an allocator test that creates a 10TiB ram backed null block device and then fallocates random files until the file system is full. I think go through and delete all of the odd files. Then I spawn 8 threads that fallocate 64MiB files (1/2 our extent size cap) until the file system is full again. I use bcc's funclatency to measure the latency of find_free_extent. The baseline results are nsecs : count distribution 0 -> 1 : 0 | | 2 -> 3 : 0 | | 4 -> 7 : 0 | | 8 -> 15 : 0 | | 16 -> 31 : 0 | | 32 -> 63 : 0 | | 64 -> 127 : 0 | | 128 -> 255 : 0 | | 256 -> 511 : 10356 |**** | 512 -> 1023 : 58242 |************************* | 1024 -> 2047 : 74418 |******************************** | 2048 -> 4095 : 90393 |****************************************| 4096 -> 8191 : 79119 |*********************************** | 8192 -> 16383 : 35614 |*************** | 16384 -> 32767 : 13418 |***** | 32768 -> 65535 : 12811 |***** | 65536 -> 131071 : 17090 |******* | 131072 -> 262143 : 26465 |*********** | 262144 -> 524287 : 40179 |***************** | 524288 -> 1048575 : 55469 |************************ | 1048576 -> 2097151 : 48807 |********************* | 2097152 -> 4194303 : 26744 |*********** | 4194304 -> 8388607 : 35351 |*************** | 8388608 -> 16777215 : 13918 |****** | 16777216 -> 33554431 : 21 | | avg = 908079 nsecs, total: 580889071441 nsecs, count: 639690 And the patch results are nsecs : count distribution 0 -> 1 : 0 | | 2 -> 3 : 0 | | 4 -> 7 : 0 | | 8 -> 15 : 0 | | 16 -> 31 : 0 | | 32 -> 63 : 0 | | 64 -> 127 : 0 | | 128 -> 255 : 0 | | 256 -> 511 : 6883 |** | 512 -> 1023 : 54346 |********************* | 1024 -> 2047 : 79170 |******************************** | 2048 -> 4095 : 98890 |****************************************| 4096 -> 8191 : 81911 |********************************* | 8192 -> 16383 : 27075 |********** | 16384 -> 32767 : 14668 |***** | 32768 -> 65535 : 13251 |***** | 65536 -> 131071 : 15340 |****** | 131072 -> 262143 : 26715 |********** | 262144 -> 524287 : 43274 |***************** | 524288 -> 1048575 : 53870 |********************* | 1048576 -> 2097151 : 55368 |********************** | 2097152 -> 4194303 : 41036 |**************** | 4194304 -> 8388607 : 24927 |********** | 8388608 -> 16777215 : 33 | | 16777216 -> 33554431 : 9 | | avg = 623599 nsecs, total: 397259314759 nsecs, count: 637042 There's a little variation in the amount of calls done because of timing of the threads with metadata requirements, but the avg, total, and count's are relatively consistent between runs (usually within 2-5% of each other). As you can see here we have around a 30% decrease in average latency with a 30% decrease in overall time spent in find_free_extent. Reviewed-by:Filipe Manana <fdmanana@suse.com> Signed-off-by:
Josef Bacik <josef@toxicpanda.com> Signed-off-by:
David Sterba <dsterba@suse.com>
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Josef Bacik authored
While adding self tests for my space index change I was hitting a problem where the space indexed tree wasn't returning the expected ->max_extent_size. This is because we will skip searching any entry that doesn't have ->bytes >= the amount of bytes we want. However we'll still set the max_extent_size based on that entry. The problem is if we don't search the bitmap we won't have ->max_extent_size set properly, so we can't really trust it. This doesn't really result in a problem per-se, it can just result in us not finding contiguous area that may exist. Fix the max_extent_size helper to return ->bytes if ->max_extent_size isn't set, and add a big comment explaining why we're doing this. Signed-off-by:
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Qu Wenruo authored
We use @nr_written to record how many pages have been started by btrfs_run_delalloc_range(). Currently there are only two cases that would populate @nr_written: - Inline extent creation - Compressed write But both cases will also set @page_started to one. In fact, in writepage_delalloc() we have the following code, showing that @nr_written is really only utilized for above two cases: /* did the fill delalloc function already unlock and start * the IO? */ if (page_started) { /* * we've unlocked the page, so we can't update * the mapping's writeback index, just update * nr_to_write. */ wbc->nr_to_write -= nr_written; return 1; } But for such cases, writepage_delalloc() will return 1, and exit __extent_writepage() without going through __extent_writepage_io(). Thus this means, inside __extent_writepage_io(), we always get @nr_written as 0. So this patch is going to remove the unnecessary parameter from the following functions: - writepage_delalloc() As @nr_written passed in is always the initial value 0. Although inside that function, we still need a local @nr_written to update wbc->nr_to_write. - __extent_writepage_io() As explained above, @nr_written passed in can only be 0. This also means we can remove one update_nr_written() call. Signed-off-by:Qu Wenruo <wqu@suse.com> Signed-off-by:
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Josef Bacik authored
We used to need the root for btrfs_reserve_metadata_bytes to check the orphan cleanup state, but we no longer need that, we simply need the fs_info. Change btrfs_reserve_metadata_bytes() to use the fs_info, and change both btrfs_block_rsv_refill() and btrfs_block_rsv_add() to do the same as they simply call btrfs_reserve_metadata_bytes() and then manipulate the block_rsv that is being used. Reviewed-by:
Nikolay Borisov <nborisov@suse.com> Signed-off-by:
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Josef Bacik authored
Now that we don't care about the stage of the orphan_cleanup_state, simply replace it with a bit on ->state to make sure we don't call the orphan cleanup every time we wander into this root. Reviewed-by:
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Josef Bacik authored
This is very old code before we were stealing from the global reserve during evict. We have proper ways to steal from the global reserve while we're evicting, so rip out this code as it's no longer necessary. Reviewed-by:
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Josef Bacik authored
I forgot to convert this over when I introduced the global reserve stealing code to the space flushing code. Evict was simply trying to make its reservation and then if it failed it would steal from the global rsv, which is racey because it's outside of the normal ticketing code. Fix this by setting ticket->steal if we are BTRFS_RESERVE_FLUSH_EVICT, and then make the priority flushing path do the steal for us. Reviewed-by:
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Josef Bacik authored
We're going to use this helper in the priority flushing loop, move this check into the helper to simplify the logic. Reviewed-by:
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Josef Bacik authored
Since we're dropping locks before we enter the priority flushing loops we could have had our ticket granted before we got the space_info->lock. So add this check to avoid doing some extra flushing in the priority flushing cases. The case in priority_reclaim_metadata_space is an optimization. Think we came in to reserve, we didn't have the space, we added our ticket to the list. But at the same time somebody was waiting on the space_info lock to add space and do btrfs_try_granting_ticket(), so we drop the lock, get satisfied, come in to do our loop, and we have been satisfied. This is the priority reclaim path, so to_reclaim could be !0 still because we may have only satisfied the priority tickets and still left non priority tickets on the list. We would then have to_reclaim but ->bytes == 0. Reviewed-by:
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Josef Bacik authored
Currently the error case for the priority tickets is handled where we deal with all of the tickets, priority and non-priority. This is OK in general, but it makes for some awkward locking. We take and drop the space_info->lock back to back because of these different types of tickets. Rework the code to handle priority ticket failures in their respective helpers. This allows us to be less wonky with our space_info->lock usage, and means that the main handler simply has to check ticket->error, as the ticket is guaranteed to be off any list and completely handled by the time it exits one of the handlers. Reviewed-by:
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Naohiro Aota authored
When mounting a device, we are reporting the zones twice: once for checking the zone attributes in btrfs_get_dev_zone_info and once for loading block groups' zone info in btrfs_load_block_group_zone_info(). With a lot of block groups, that leads to a lot of REPORT ZONE commands and slows down the mount process. This patch introduces a zone info cache in struct btrfs_zoned_device_info. The cache is populated while in btrfs_get_dev_zone_info() and used for btrfs_load_block_group_zone_info() to reduce the number of REPORT ZONE commands. The zone cache is then released after loading the block groups, as it will not be much effective during the run time. Benchmark: Mount an HDD with 57,007 block groups Before patch: 171.368 seconds After patch: 64.064 seconds While it still takes a minute due to the slowness of loading all the block groups, the patch reduces the mount time by 1/3. Link: https://lore.kernel.org/linux-btrfs/CAHQ7scUiLtcTqZOMMY5kbWUBOhGRwKo6J6wYPT5WY+C=cD49nQ@mail.gmail.com/ Fixes: 5b316468 ("btrfs: get zone information of zoned block devices") CC: stable@vger.kernel.org Signed-off-by:
Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by:
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Su Yue authored
Since commit ba8a9d07 ("Btrfs: delete the entire async bio submission framework") removed submit workqueues, the parameter fs_devices is not used anymore. Remove it, no functional changes. Reviewed-by:
Anand Jain <anand.jain@oracle.com> Signed-off-by:
Su Yue <l@damenly.su> Reviewed-by:
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Filipe Manana authored
In the transaction commit path we are acquiring the tree log mutex too early and we have a stale comment because: 1) It mentions a function named btrfs_commit_tree_roots(), which does not exists anymore, it was the old name of commit_cowonly_roots(), renamed a very long time ago by commit 5d4f98a2 ("Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE)")); 2) It mentions that we need to acquire the tree log mutex at that point to ensure we have no running log writers. That is not correct anymore, for many years at least, since we are guaranteed that we do not have any log writers at that point simply because we have set the state of the transaction to TRANS_STATE_COMMIT_DOING and have waited for all writers to complete - meaning no one can log until we change the state of the transaction to TRANS_STATE_UNBLOCKED. Any attempts to join the transaction or start a new one will block until we do that state transition; 3) The comment mentions a "trans mutex" which doesn't exists since 2011, commit a4abeea4 ("Btrfs: kill trans_mutex") removed it; 4) The current use of the tree log mutex is to ensure proper serialization of super block writes - if someone started a new transaction and uses it for logging, it will wait for the previous transaction to write its super block before writing the super block when attempting to sync the log. So acquire the tree log mutex only when it's absolutely needed, before setting the transaction state to TRANS_STATE_UNBLOCKED, fix and move the stale comment, add some assertions and new comments where appropriate. Also, this has no effect on concurrency or performance, since the new start of the critical section is still when the transaction is in the state TRANS_STATE_COMMIT_DOING. Reviewed-by:
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Anand Jain authored
btrfs_prepare_sprout() splices seed devices into its own struct fs_devices, so that its parent function btrfs_init_new_device() can add the new sprout device to fs_info->fs_devices. Both btrfs_prepare_sprout() and btrfs_init_new_device() need device_list_mutex. But they are holding it separately, thus create a small race window. Close it and hold device_list_mutex across both functions btrfs_init_new_device() and btrfs_prepare_sprout(). Split btrfs_prepare_sprout() into btrfs_init_sprout() and btrfs_setup_sprout(). This split is essential because device_list_mutex must not be held for allocations in btrfs_init_sprout() but must be held for btrfs_setup_sprout(). So now a common device_list_mutex can be used between btrfs_init_new_device() and btrfs_setup_sprout(). Reviewed-by:
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Anand Jain authored
Declare int seeding_dev as a bool. Also, move its declaration a line below to adjust packing. Reviewed-by:
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Omar Sandoval authored
Again, I don't think this was ever used since iterate_dir_item() is only used for xattrs. No functional change. Reviewed-by:
Omar Sandoval <osandov@fb.com> Reviewed-by:
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Omar Sandoval authored
As far as I can tell, this was never used. No functional change. Reviewed-by:
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Josef Bacik authored
The name btrfs_item_end_nr() is a bit of a misnomer, as it's actually the offset of the end of the data the item points to. In fact all of the helpers that we use btrfs_item_end_nr() use data in their name, like BTRFS_LEAF_DATA_SIZE() and leaf_data(). Rename to btrfs_item_data_end() to make it clear what this helper is giving us. Signed-off-by:
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Josef Bacik authored
We're only using btrfs_item_end() from btrfs_item_end_nr(), so this can be collapsed. Signed-off-by:
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Josef Bacik authored
Now that all call sites are using the slot number to modify item values, rename the SETGET helpers to raw_item_*(), and then rework the _nr() helpers to be the btrfs_item_*() btrfs_set_item_*() helpers, and then rename all of the callers to the new helpers. Signed-off-by:
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Josef Bacik authored
The last remaining place where we have the pattern of item = btrfs_item_nr(slot) <do something with the item> are the token helpers. Handle this by introducing token helpers that will do the btrfs_item_nr() work inside of the helper itself, and then convert all users of the btrfs_item token helpers to the new _nr() variants. Signed-off-by:
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Josef Bacik authored
Instead of getting the btrfs_item for this, simply pass in the slot of the item and then use the btrfs_item_size_nr() helper inside of btrfs_file_extent_inline_item_len(). Signed-off-by:
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Josef Bacik authored
We have the pattern of item = btrfs_item_nr(slot); btrfs_set_item_*(leaf, item); in a bunch of places in our code. Fix this by adding btrfs_set_item_*_nr() helpers which will do the appropriate work, and replace those calls with btrfs_set_item_*_nr(leaf, slot); Signed-off-by:
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Josef Bacik authored
We have this pattern in a lot of places item = btrfs_item_nr(slot); btrfs_item_size(leaf, item); when we could simply use btrfs_item_size(leaf, slot); Fix all callers of btrfs_item_size() and btrfs_item_offset() to use the _nr variation of the helpers. Reviewed-by:
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Filipe Manana authored
Now that we log only dir index keys when logging a directory, we no longer need to deal with dir item keys in the log replay code for replaying directory deletes. This is also true for the case when we replay a log tree created by a kernel that still logs dir items. So remove the remaining code of the replay of directory deletes algorithm that deals with dir item keys. Reviewed-by:
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Filipe Manana authored
Currently, when logging a directory, we copy both dir items and dir index items from the fs/subvolume tree to the log tree. Both items have exactly the same data (same struct btrfs_dir_item), the difference lies in the key values, where a dir index key contains the index number of a directory entry while the dir item key does not, as it's used for doing fast lookups of an entry by name, while the former is used for sorting entries when listing a directory. We can exploit that and log only the dir index items, since they contain all the information needed to correctly add, replace and delete directory entries when replaying a log tree. Logging only the dir index items is also backward and forward compatible: an unpatched kernel (without this change) can correctly replay a log tree generated by a patched kernel (with this patch), and a patched kernel can correctly replay a log tree generated by an unpatched kernel. The backward compatibility is ensured because: 1) For inserting a new dentry: a dentry is only inserted when we find a new dir index key - we can only insert if we know the dir index offset, which is encoded in the dir index key's offset; 2) For deleting dentries: during log replay, before adding or replacing dentries, we first replay dentry deletions. Whenever we find a dir item key or a dir index key in the subvolume/fs tree that is not logged in a range for which the log tree is authoritative, we do the unlink of the dentry, which removes both the existing dir item key and the dir index key. Therefore logging just dir index keys is enough to ensure dentry deletions are correctly replayed; 3) For dentry replacements: they work when we log only dir index keys and this is mostly due to a combination of 1) and 2). If we replace a dentry with name "foobar" to point from inode A to inode B, then we know the dir index key for the new dentry is different from the old one, as it has an index number (key offset) larger than the old one. This results in replaying a deletion, through replay_dir_deletes(), that causes the old dentry to be removed, both the dir item key and the dir index key, as mentioned at 2). Then when processing the new dir index key, we add the new dentry, adding both a new dir item key and a new index key pointing to inode B, as stated in 1). The forward compatibility, the ability for a patched kernel to replay a log created by an older, unpatched kernel, comes from the changes required for making sure we are able to replay a log that only contains dir index keys - we simply ignore every dir item key we find. So modify directory logging to log only dir index items, and modify the log replay process to ignore dir item keys, from log trees created by an unpatched kernel, and process only with dir index keys. This reduces the amount of logged metadata by about half, and therefore the time spent logging or fsyncing large directories (less CPU time and less IO). The following test script was used to measure this change: #!/bin/bash DEV=/dev/nvme0n1 MNT=/mnt/nvme0n1 NUM_NEW_FILES=1000000 NUM_FILE_DELETES=10000 mkfs.btrfs -f $DEV mount -o ssd $DEV $MNT mkdir $MNT/testdir for ((i = 1; i <= $NUM_NEW_FILES; i++)); do echo -n > $MNT/testdir/file_$i done start=$(date +%s%N) xfs_io -c "fsync" $MNT/testdir end=$(date +%s%N) dur=$(( (end - start) / 1000000 )) echo "dir fsync took $dur ms after adding $NUM_NEW_FILES files" # sync to force transaction commit and wipeout the log. sync del_inc=$(( $NUM_NEW_FILES / $NUM_FILE_DELETES )) for ((i = 1; i <= $NUM_NEW_FILES; i += $del_inc)); do rm -f $MNT/testdir/file_$i done start=$(date +%s%N) xfs_io -c "fsync" $MNT/testdir end=$(date +%s%N) dur=$(( (end - start) / 1000000 )) echo "dir fsync took $dur ms after deleting $NUM_FILE_DELETES files" echo umount $MNT The tests were run on a physical machine, with a non-debug kernel (Debian's default kernel config), for different values of $NUM_NEW_FILES and $NUM_FILE_DELETES, and the results were the following: ** Before patch, NUM_NEW_FILES = 1 000 000, NUM_DELETE_FILES = 10 000 ** dir fsync took 8412 ms after adding 1000000 files dir fsync took 500 ms after deleting 10000 files ** After patch, NUM_NEW_FILES = 1 000 000, NUM_DELETE_FILES = 10 000 ** dir fsync took 4252 ms after adding 1000000 files (-49.5%) dir fsync took 269 ms after deleting 10000 files (-46.2%) ** Before patch, NUM_NEW_FILES = 100 000, NUM_DELETE_FILES = 1 000 ** dir fsync took 745 ms after adding 100000 files dir fsync took 59 ms after deleting 1000 files ** After patch, NUM_NEW_FILES = 100 000, NUM_DELETE_FILES = 1 000 ** dir fsync took 404 ms after adding 100000 files (-45.8%) dir fsync took 31 ms after deleting 1000 files (-47.5%) ** Before patch, NUM_NEW_FILES = 10 000, NUM_DELETE_FILES = 1 000 ** dir fsync took 67 ms after adding 10000 files dir fsync took 9 ms after deleting 1000 files ** After patch, NUM_NEW_FILES = 10 000, NUM_DELETE_FILES = 1 000 ** dir fsync took 36 ms after adding 10000 files (-46.3%) dir fsync took 5 ms after deleting 1000 files (-44.4%) ** Before patch, NUM_NEW_FILES = 1 000, NUM_DELETE_FILES = 100 ** dir fsync took 9 ms after adding 1000 files dir fsync took 4 ms after deleting 100 files ** After patch, NUM_NEW_FILES = 1 000, NUM_DELETE_FILES = 100 ** dir fsync took 7 ms after adding 1000 files (-22.2%) dir fsync took 3 ms after deleting 100 files (-25.0%) Reviewed-by: -
Nikolay Borisov authored
Since both unused block groups and reclaim bgs lists are protected by unused_bgs_lock then free them in the same critical section without doing an extra unlock/lock pair. Reviewed-by:
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Filipe Manana authored
When enabling quotas, we attempt to commit a transaction while holding the mutex fs_info->qgroup_ioctl_lock. This can result on a deadlock with other quota operations such as: - qgroup creation and deletion, ioctl BTRFS_IOC_QGROUP_CREATE; - adding and removing qgroup relations, ioctl BTRFS_IOC_QGROUP_ASSIGN. This is because these operations join a transaction and after that they attempt to lock the mutex fs_info->qgroup_ioctl_lock. Acquiring that mutex after joining or starting a transaction is a pattern followed everywhere in qgroups, so the quota enablement operation is the one at fault here, and should not commit a transaction while holding that mutex. Fix this by making the transaction commit while not holding the mutex. We are safe from two concurrent tasks trying to enable quotas because we are serialized by the rw semaphore fs_info->subvol_sem at btrfs_ioctl_quota_ctl(), which is the only call site for enabling quotas. When this deadlock happens, it produces a trace like the following: INFO: task syz-executor:25604 blocked for more than 143 seconds. Not tainted 5.15.0-rc6 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:24800 pid:25604 ppid: 24873 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xcd9/0x2530 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 btrfs_commit_transaction+0x994/0x2e90 fs/btrfs/transaction.c:2201 btrfs_quota_enable+0x95c/0x1790 fs/btrfs/qgroup.c:1120 btrfs_ioctl_quota_ctl fs/btrfs/ioctl.c:4229 [inline] btrfs_ioctl+0x637e/0x7b70 fs/btrfs/ioctl.c:5010 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f86920b2c4d RSP: 002b:00007f868f61ac58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f86921d90a0 RCX: 00007f86920b2c4d RDX: 0000000020005e40 RSI: 00000000c0109428 RDI: 0000000000000008 RBP: 00007f869212bd80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f86921d90a0 R13: 00007fff6d233e4f R14: 00007fff6d233ff0 R15: 00007f868f61adc0 INFO: task syz-executor:25628 blocked for more than 143 seconds. Not tainted 5.15.0-rc6 #4 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:29080 pid:25628 ppid: 24873 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4940 [inline] __schedule+0xcd9/0x2530 kernel/sched/core.c:6287 schedule+0xd3/0x270 kernel/sched/core.c:6366 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6425 __mutex_lock_common kernel/locking/mutex.c:669 [inline] __mutex_lock+0xc96/0x1680 kernel/locking/mutex.c:729 btrfs_remove_qgroup+0xb7/0x7d0 fs/btrfs/qgroup.c:1548 btrfs_ioctl_qgroup_create fs/btrfs/ioctl.c:4333 [inline] btrfs_ioctl+0x683c/0x7b70 fs/btrfs/ioctl.c:5014 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported-by:
Hao Sun <sunhao.th@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CACkBjsZQF19bQ1C6=yetF3BvL10OSORpFUcWXTP6HErshDB4dQ@mail.gmail.com/ Fixes: 340f1aa2 ("btrfs: qgroups: Move transaction management inside btrfs_quota_enable/disable") CC: stable@vger.kernel.org # 4.19 Reviewed-by:
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Filipe Manana authored
When doing a direct IO write against a file range that either has preallocated extents in that range or has regular extents and the file has the NOCOW attribute set, the write fails with -ENOSPC when all of the following conditions are met: 1) There are no data blocks groups with enough free space matching the size of the write; 2) There's not enough unallocated space for allocating a new data block group; 3) The extents in the target file range are not shared, neither through snapshots nor through reflinks. This is wrong because a NOCOW write can be done in such case, and in fact it's possible to do it using a buffered IO write, since when failing to allocate data space, the buffered IO path checks if a NOCOW write is possible. The failure in direct IO write path comes from the fact that early on, at btrfs_dio_iomap_begin(), we try to allocate data space for the write and if it that fails we return the error and stop - we never check if we can do NOCOW. But later, at btrfs_get_blocks_direct_write(), we check if we can do a NOCOW write into the range, or a subset of the range, and then release the previously reserved data space. Fix this by doing the data reservation only if needed, when we must COW, at btrfs_get_blocks_direct_write() instead of doing it at btrfs_dio_iomap_begin(). This also simplifies a bit the logic and removes the inneficiency of doing unnecessary data reservations. The following example test script reproduces the problem: $ cat dio-nocow-enospc.sh #!/bin/bash DEV=/dev/sdj MNT=/mnt/sdj # Use a small fixed size (1G) filesystem so that it's quick to fill # it up. # Make sure the mixed block groups feature is not enabled because we # later want to not have more space available for allocating data # extents but still have enough metadata space free for the file writes. mkfs.btrfs -f -b $((1024 * 1024 * 1024)) -O ^mixed-bg $DEV mount $DEV $MNT # Create our test file with the NOCOW attribute set. touch $MNT/foobar chattr +C $MNT/foobar # Now fill in all unallocated space with data for our test file. # This will allocate a data block group that will be full and leave # no (or a very small amount of) unallocated space in the device, so # that it will not be possible to allocate a new block group later. echo echo "Creating test file with initial data..." xfs_io -c "pwrite -S 0xab -b 1M 0 900M" $MNT/foobar # Now try a direct IO write against file range [0, 10M[. # This should succeed since this is a NOCOW file and an extent for the # range was previously allocated. echo echo "Trying direct IO write over allocated space..." xfs_io -d -c "pwrite -S 0xcd -b 10M 0 10M" $MNT/foobar umount $MNT When running the test: $ ./dio-nocow-enospc.sh (...) Creating test file with initial data... wrote 943718400/943718400 bytes at offset 0 900 MiB, 900 ops; 0:00:01.43 (625.526 MiB/sec and 625.5265 ops/sec) Trying direct IO write over allocated space... pwrite: No space left on device A test case for fstests will follow, testing both this direct IO write scenario as well as the buffered IO write scenario to make it less likely to get future regressions on the buffered IO case. Reviewed-by:
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- 02 Jan, 2022 6 commits
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Linus Torvalds authored
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Linus Torvalds authored
Merge tag 'perf-tools-fixes-for-v5.16-2022-01-02' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux Pull perf tools fixes from Arnaldo Carvalho de Melo: - Fix TUI exit screen refresh race condition in 'perf top'. - Fix parsing of Intel PT VM time correlation arguments. - Honour CPU filtering command line request of a script's switch events in 'perf script'. - Fix printing of switch events in Intel PT python script. - Fix duplicate alias events list printing in 'perf list', noticed on heterogeneous arm64 systems. - Fix return value of ids__new(), users expect NULL for failure, not ERR_PTR(-ENOMEM). * tag 'perf-tools-fixes-for-v5.16-2022-01-02' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: perf top: Fix TUI exit screen refresh race condition perf pmu: Fix alias events list perf scripts python: intel-pt-events.py: Fix printing of switch events perf script: Fix CPU filtering of a script's switch events perf intel-pt: Fix parsing of VM time correlation arguments perf expr: Fix return value of ids__new()
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git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linuxLinus Torvalds authored
Pull i2c fixes from Wolfram Sang: "Better input validation for compat ioctls and a documentation bugfix for 5.16" * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: Docs: Fixes link to I2C specification i2c: validate user data in compat ioctl
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fix from Borislav Petkov: - Use the proper CONFIG symbol in a preprocessor check. * tag 'x86_urgent_for_v5.16_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/build: Use the proper name CONFIG_FW_LOADER
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yaowenbin authored
When the following command is executed several times, a coredump file is generated. $ timeout -k 9 5 perf top -e task-clock ******* ******* ******* 0.01% [kernel] [k] __do_softirq 0.01% libpthread-2.28.so [.] __pthread_mutex_lock 0.01% [kernel] [k] __ll_sc_atomic64_sub_return double free or corruption (!prev) perf top --sort comm,dso timeout: the monitored command dumped core When we terminate "perf top" using sending signal method, SLsmg_reset_smg() called. SLsmg_reset_smg() resets the SLsmg screen management routines by freeing all memory allocated while it was active. However SLsmg_reinit_smg() maybe be called by another thread. SLsmg_reinit_smg() will free the same memory accessed by SLsmg_reset_smg(), thus it results in a double free. SLsmg_reinit_smg() is called already protected by ui__lock, so we fix the problem by adding pthread_mutex_trylock of ui__lock when calling SLsmg_reset_smg(). Signed-off-by:
Wenyu Liu <liuwenyu7@huawei.com> Tested-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: wuxu.wu@huawei.com Link: http://lore.kernel.org/lkml/a91e3943-7ddc-f5c0-a7f5-360f073c20e6@huawei.comSigned-off-by:
Hewenliang <hewenliang4@huawei.com> Signed-off-by:
yaowenbin <yaowenbin1@huawei.com> Signed-off-by:
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John Garry authored
Commit 0e0ae874 ("perf list: Display hybrid PMU events with cpu type") changes the event list for uncore PMUs or arm64 heterogeneous CPU systems, such that duplicate aliases are incorrectly listed per PMU (which they should not be), like: # perf list ... unc_cbo_cache_lookup.any_es [Unit: uncore_cbox L3 Lookup any request that access cache and found line in E or S-state] unc_cbo_cache_lookup.any_es [Unit: uncore_cbox L3 Lookup any request that access cache and found line in E or S-state] unc_cbo_cache_lookup.any_i [Unit: uncore_cbox L3 Lookup any request that access cache and found line in I-state] unc_cbo_cache_lookup.any_i [Unit: uncore_cbox L3 Lookup any request that access cache and found line in I-state] ... Notice how the events are listed twice. The named commit changed how we remove duplicate events, in that events for different PMUs are not treated as duplicates. I suppose this is to handle how "Each hybrid pmu event has been assigned with a pmu name". Fix PMU alias listing by restoring behaviour to remove duplicates for non-hybrid PMUs. Fixes: 0e0ae874 ("perf list: Display hybrid PMU events with cpu type") Signed-off-by:
John Garry <john.garry@huawei.com> Tested-by:
Zhengjun Xing <zhengjun.xing@linux.intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/1640103090-140490-1-git-send-email-john.garry@huawei.comSigned-off-by:
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- 01 Jan, 2022 1 commit
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git://git.kernel.org/pub/scm/linux/kernel/git/dtor/inputLinus Torvalds authored
Pull input fixes from Dmitry Torokhov: "Two small fixups for spaceball joystick driver and appletouch touchpad driver" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: spaceball - fix parsing of movement data packets Input: appletouch - initialize work before device registration
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- 31 Dec, 2021 4 commits
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Mel Gorman authored
Hugh Dickins reported the following My tmpfs swapping load (tweaked to use huge pages more heavily than in real life) is far from being a realistic load: but it was notably slowed down by your throttling mods in 5.16-rc, and this patch makes it well again - thanks. But: it very quickly hit NULL pointer until I changed that last line to if (first_pgdat) consider_reclaim_throttle(first_pgdat, sc); The likely issue is that huge pages are a major component of the test workload. When this is the case, first_pgdat may never get set if compaction is ready to continue due to this check if (IS_ENABLED(CONFIG_COMPACTION) && sc->order > PAGE_ALLOC_COSTLY_ORDER && compaction_ready(zone, sc)) { sc->compaction_ready = true; continue; } If this was true for every zone in the zonelist, first_pgdat would never get set resulting in a NULL pointer exception. Link: https://lkml.kernel.org/r/20211209095453.GM3366@techsingularity.net Fixes: 1b4e3f26 ("mm: vmscan: Reduce throttling due to a failure to make progress") Signed-off-by:Mel Gorman <mgorman@techsingularity.net> Reported-by:
Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Rik van Riel <riel@surriel.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Mel Gorman authored
Mike Galbraith, Alexey Avramov and Darrick Wong all reported similar problems due to reclaim throttling for excessive lengths of time. In Alexey's case, a memory hog that should go OOM quickly stalls for several minutes before stalling. In Mike and Darrick's cases, a small memcg environment stalled excessively even though the system had enough memory overall. Commit 69392a40 ("mm/vmscan: throttle reclaim when no progress is being made") introduced the problem although commit a19594ca ("mm/vmscan: increase the timeout if page reclaim is not making progress") made it worse. Systems at or near an OOM state that cannot be recovered must reach OOM quickly and memcg should kill tasks if a memcg is near OOM. To address this, only stall for the first zone in the zonelist, reduce the timeout to 1 tick for VMSCAN_THROTTLE_NOPROGRESS and only stall if the scan control nr_reclaimed is 0, kswapd is still active and there were excessive pages pending for writeback. If kswapd has stopped reclaiming due to excessive failures, do not stall at all so that OOM triggers relatively quickly. Similarly, if an LRU is simply congested, only lightly throttle similar to NOPROGRESS. Alexey's original case was the most straight forward for i in {1..3}; do tail /dev/zero; done On vanilla 5.16-rc1, this test stalled heavily, after the patch the test completes in a few seconds similar to 5.15. Alexey's second test case added watching a youtube video while tail runs 10 times. On 5.15, playback only jitters slightly, 5.16-rc1 stalls a lot with lots of frames missing and numerous audio glitches. With this patch applies, the video plays similarly to 5.15. [lkp@intel.com: Fix W=1 build warning] Link: https://lore.kernel.org/r/99e779783d6c7fce96448a3402061b9dc1b3b602.camel@gmx.de Link: https://lore.kernel.org/r/20211124011954.7cab9bb4@mail.inbox.lv Link: https://lore.kernel.org/r/20211022144651.19914-1-mgorman@techsingularity.net Link: https://lore.kernel.org/r/20211202150614.22440-1-mgorman@techsingularity.net Link: https://linux-regtracking.leemhuis.info/regzbot/regression/20211124011954.7cab9bb4@mail.inbox.lv/Reported-and-tested-by:
Alexey Avramov <hakavlad@inbox.lv> Reported-and-tested-by:
Mike Galbraith <efault@gmx.de> Reported-and-tested-by:
Darrick J. Wong <djwong@kernel.org> Reported-by:
kernel test robot <lkp@intel.com> Acked-by:
Thorsten Leemhuis <regressions@leemhuis.info> Fixes: 69392a40 ("mm/vmscan: throttle reclaim when no progress is being made") Signed-off-by:
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Linus Torvalds authored
Merge misc mm fixes from Andrew Morton: "2 patches. Subsystems affected by this patch series: mm (userfaultfd and damon)" * akpm: mm/damon/dbgfs: fix 'struct pid' leaks in 'dbgfs_target_ids_write()' userfaultfd/selftests: fix hugetlb area allocations
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git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds authored
Pull SCSI fixes from James Bottomley: "Three fixes, all in drivers. The lpfc one doesn't look exploitable, but nasty things could happen in string operations if mybuf ends up with an on stack unterminated string" * tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: scsi: vmw_pvscsi: Set residual data length conditionally scsi: libiscsi: Fix UAF in iscsi_conn_get_param()/iscsi_conn_teardown() scsi: lpfc: Terminate string in lpfc_debugfs_nvmeio_trc_write()
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