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2021-12-15btrfs: fix missing blkdev_put() call in btrfs_scan_one_device()Shin'ichiro Kawasaki
The function btrfs_scan_one_device() calls blkdev_get_by_path() and blkdev_put() to get and release its target block device. However, when btrfs_sb_log_location_bdev() fails, blkdev_put() is not called and the block device is left without clean up. This triggered failure of fstests generic/085. Fix the failure path of btrfs_sb_log_location_bdev() to call blkdev_put(). Fixes: 12659251ca5df ("btrfs: implement log-structured superblock for ZONED mode") CC: stable@vger.kernel.org # 5.15+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-12-15btrfs: fix warning when freeing leaf after subvolume creation failureFilipe Manana
When creating a subvolume, at ioctl.c:create_subvol(), if we fail to insert the root item for the new subvolume into the root tree, we can trigger the following warning: [78961.741046] WARNING: CPU: 0 PID: 4079814 at fs/btrfs/extent-tree.c:3357 btrfs_free_tree_block+0x2af/0x310 [btrfs] [78961.743344] Modules linked in: [78961.749440] dm_snapshot dm_thin_pool (...) [78961.773648] CPU: 0 PID: 4079814 Comm: fsstress Not tainted 5.16.0-rc4-btrfs-next-108 #1 [78961.775198] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [78961.777266] RIP: 0010:btrfs_free_tree_block+0x2af/0x310 [btrfs] [78961.778398] Code: 17 00 48 85 (...) [78961.781067] RSP: 0018:ffffaa4001657b28 EFLAGS: 00010202 [78961.781877] RAX: 0000000000000213 RBX: ffff897f8a796910 RCX: 0000000000000000 [78961.782780] RDX: 0000000000000000 RSI: 0000000011004000 RDI: 00000000ffffffff [78961.783764] RBP: ffff8981f490e800 R08: 0000000000000001 R09: 0000000000000000 [78961.784740] R10: 0000000000000000 R11: 0000000000000001 R12: ffff897fc963fcc8 [78961.785665] R13: 0000000000000001 R14: ffff898063548000 R15: ffff898063548000 [78961.786620] FS: 00007f31283c6b80(0000) GS:ffff8982ace00000(0000) knlGS:0000000000000000 [78961.787717] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [78961.788598] CR2: 00007f31285c3000 CR3: 000000023fcc8003 CR4: 0000000000370ef0 [78961.789568] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [78961.790585] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [78961.791684] Call Trace: [78961.792082] <TASK> [78961.792359] create_subvol+0x5d1/0x9a0 [btrfs] [78961.793054] btrfs_mksubvol+0x447/0x4c0 [btrfs] [78961.794009] ? preempt_count_add+0x49/0xa0 [78961.794705] __btrfs_ioctl_snap_create+0x123/0x190 [btrfs] [78961.795712] ? _copy_from_user+0x66/0xa0 [78961.796382] btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs] [78961.797392] btrfs_ioctl+0xd1e/0x35c0 [btrfs] [78961.798172] ? __slab_free+0x10a/0x360 [78961.798820] ? rcu_read_lock_sched_held+0x12/0x60 [78961.799664] ? lock_release+0x223/0x4a0 [78961.800321] ? lock_acquired+0x19f/0x420 [78961.800992] ? rcu_read_lock_sched_held+0x12/0x60 [78961.801796] ? trace_hardirqs_on+0x1b/0xe0 [78961.802495] ? _raw_spin_unlock_irqrestore+0x3e/0x60 [78961.803358] ? kmem_cache_free+0x321/0x3c0 [78961.804071] ? __x64_sys_ioctl+0x83/0xb0 [78961.804711] __x64_sys_ioctl+0x83/0xb0 [78961.805348] do_syscall_64+0x3b/0xc0 [78961.805969] entry_SYSCALL_64_after_hwframe+0x44/0xae [78961.806830] RIP: 0033:0x7f31284bc957 [78961.807517] Code: 3c 1c 48 f7 d8 (...) This is because we are calling btrfs_free_tree_block() on an extent buffer that is dirty. Fix that by cleaning the extent buffer, with btrfs_clean_tree_block(), before freeing it. This was triggered by test case generic/475 from fstests. Fixes: 67addf29004c5b ("btrfs: fix metadata extent leak after failure to create subvolume") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-12-15btrfs: fix invalid delayed ref after subvolume creation failureFilipe Manana
When creating a subvolume, at ioctl.c:create_subvol(), if we fail to insert the new root's root item into the root tree, we are freeing the metadata extent we reserved for the new root to prevent a metadata extent leak, as we don't abort the transaction at that point (since there is nothing at that point that is irreversible). However we allocated the metadata extent for the new root which we are creating for the new subvolume, so its delayed reference refers to the ID of this new root. But when we free the metadata extent we pass the root of the subvolume where the new subvolume is located to btrfs_free_tree_block() - this is incorrect because this will generate a delayed reference that refers to the ID of the parent subvolume's root, and not to ID of the new root. This results in a failure when running delayed references that leads to a transaction abort and a trace like the following: [3868.738042] RIP: 0010:__btrfs_free_extent+0x709/0x950 [btrfs] [3868.739857] Code: 68 0f 85 e6 fb ff (...) [3868.742963] RSP: 0018:ffffb0e9045cf910 EFLAGS: 00010246 [3868.743908] RAX: 00000000fffffffe RBX: 00000000fffffffe RCX: 0000000000000002 [3868.745312] RDX: 00000000fffffffe RSI: 0000000000000002 RDI: ffff90b0cd793b88 [3868.746643] RBP: 000000000e5d8000 R08: 0000000000000000 R09: ffff90b0cd793b88 [3868.747979] R10: 0000000000000002 R11: 00014ded97944d68 R12: 0000000000000000 [3868.749373] R13: ffff90b09afe4a28 R14: 0000000000000000 R15: ffff90b0cd793b88 [3868.750725] FS: 00007f281c4a8b80(0000) GS:ffff90b3ada00000(0000) knlGS:0000000000000000 [3868.752275] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [3868.753515] CR2: 00007f281c6a5000 CR3: 0000000108a42006 CR4: 0000000000370ee0 [3868.754869] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [3868.756228] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [3868.757803] Call Trace: [3868.758281] <TASK> [3868.758655] ? btrfs_merge_delayed_refs+0x178/0x1c0 [btrfs] [3868.759827] __btrfs_run_delayed_refs+0x2b1/0x1250 [btrfs] [3868.761047] btrfs_run_delayed_refs+0x86/0x210 [btrfs] [3868.762069] ? lock_acquired+0x19f/0x420 [3868.762829] btrfs_commit_transaction+0x69/0xb20 [btrfs] [3868.763860] ? _raw_spin_unlock+0x29/0x40 [3868.764614] ? btrfs_block_rsv_release+0x1c2/0x1e0 [btrfs] [3868.765870] create_subvol+0x1d8/0x9a0 [btrfs] [3868.766766] btrfs_mksubvol+0x447/0x4c0 [btrfs] [3868.767669] ? preempt_count_add+0x49/0xa0 [3868.768444] __btrfs_ioctl_snap_create+0x123/0x190 [btrfs] [3868.769639] ? _copy_from_user+0x66/0xa0 [3868.770391] btrfs_ioctl_snap_create_v2+0xbb/0x140 [btrfs] [3868.771495] btrfs_ioctl+0xd1e/0x35c0 [btrfs] [3868.772364] ? __slab_free+0x10a/0x360 [3868.773198] ? rcu_read_lock_sched_held+0x12/0x60 [3868.774121] ? lock_release+0x223/0x4a0 [3868.774863] ? lock_acquired+0x19f/0x420 [3868.775634] ? rcu_read_lock_sched_held+0x12/0x60 [3868.776530] ? trace_hardirqs_on+0x1b/0xe0 [3868.777373] ? _raw_spin_unlock_irqrestore+0x3e/0x60 [3868.778280] ? kmem_cache_free+0x321/0x3c0 [3868.779011] ? __x64_sys_ioctl+0x83/0xb0 [3868.779718] __x64_sys_ioctl+0x83/0xb0 [3868.780387] do_syscall_64+0x3b/0xc0 [3868.781059] entry_SYSCALL_64_after_hwframe+0x44/0xae [3868.781953] RIP: 0033:0x7f281c59e957 [3868.782585] Code: 3c 1c 48 f7 d8 4c (...) [3868.785867] RSP: 002b:00007ffe1f83e2b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [3868.787198] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f281c59e957 [3868.788450] RDX: 00007ffe1f83e2c0 RSI: 0000000050009418 RDI: 0000000000000003 [3868.789748] RBP: 00007ffe1f83f300 R08: 0000000000000000 R09: 00007ffe1f83fe36 [3868.791214] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000003 [3868.792468] R13: 0000000000000003 R14: 00007ffe1f83e2c0 R15: 00000000000003cc [3868.793765] </TASK> [3868.794037] irq event stamp: 0 [3868.794548] hardirqs last enabled at (0): [<0000000000000000>] 0x0 [3868.795670] hardirqs last disabled at (0): [<ffffffff98294214>] copy_process+0x934/0x2040 [3868.797086] softirqs last enabled at (0): [<ffffffff98294214>] copy_process+0x934/0x2040 [3868.798309] softirqs last disabled at (0): [<0000000000000000>] 0x0 [3868.799284] ---[ end trace be24c7002fe27747 ]--- [3868.799928] BTRFS info (device dm-0): leaf 241188864 gen 1268 total ptrs 214 free space 469 owner 2 [3868.801133] BTRFS info (device dm-0): refs 2 lock_owner 225627 current 225627 [3868.802056] item 0 key (237436928 169 0) itemoff 16250 itemsize 33 [3868.802863] extent refs 1 gen 1265 flags 2 [3868.803447] ref#0: tree block backref root 1610 (...) [3869.064354] item 114 key (241008640 169 0) itemoff 12488 itemsize 33 [3869.065421] extent refs 1 gen 1268 flags 2 [3869.066115] ref#0: tree block backref root 1689 (...) [3869.403834] BTRFS error (device dm-0): unable to find ref byte nr 241008640 parent 0 root 1622 owner 0 offset 0 [3869.405641] BTRFS: error (device dm-0) in __btrfs_free_extent:3076: errno=-2 No such entry [3869.407138] BTRFS: error (device dm-0) in btrfs_run_delayed_refs:2159: errno=-2 No such entry Fix this by passing the new subvolume's root ID to btrfs_free_tree_block(). This requires changing the root argument of btrfs_free_tree_block() from struct btrfs_root * to a u64, since at this point during the subvolume creation we have not yet created the struct btrfs_root for the new subvolume, and btrfs_free_tree_block() only needs a root ID and nothing else from a struct btrfs_root. This was triggered by test case generic/475 from fstests. Fixes: 67addf29004c5b ("btrfs: fix metadata extent leak after failure to create subvolume") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-12-15btrfs: check WRITE_ERR when trying to read an extent bufferJosef Bacik
Filipe reported a hang when we have errors on btrfs. This turned out to be a side-effect of my fix c2e39305299f01 ("btrfs: clear extent buffer uptodate when we fail to write it") which made it so we clear EXTENT_BUFFER_UPTODATE on an eb when we fail to write it out. Below is a paste of Filipe's analysis he got from using drgn to debug the hang """ btree readahead code calls read_extent_buffer_pages(), sets ->io_pages to a value while writeback of all pages has not yet completed: --> writeback for the first 3 pages finishes, we clear EXTENT_BUFFER_UPTODATE from eb on the first page when we get an error. --> at this point eb->io_pages is 1 and we cleared Uptodate bit from the first 3 pages --> read_extent_buffer_pages() does not see EXTENT_BUFFER_UPTODATE() so it continues, it's able to lock the pages since we obviously don't hold the pages locked during writeback --> read_extent_buffer_pages() then computes 'num_reads' as 3, and sets eb->io_pages to 3, since only the first page does not have Uptodate bit set at this point --> writeback for the remaining page completes, we ended decrementing eb->io_pages by 1, resulting in eb->io_pages == 2, and therefore never calling end_extent_buffer_writeback(), so EXTENT_BUFFER_WRITEBACK remains in the eb's flags --> of course, when the read bio completes, it doesn't and shouldn't call end_extent_buffer_writeback() --> we should clear EXTENT_BUFFER_UPTODATE only after all pages of the eb finished writeback? or maybe make the read pages code wait for writeback of all pages of the eb to complete before checking which pages need to be read, touch ->io_pages, submit read bio, etc writeback bit never cleared means we can hang when aborting a transaction, at: btrfs_cleanup_one_transaction() btrfs_destroy_marked_extents() wait_on_extent_buffer_writeback() """ This is a problem because our writes are not synchronized with reads in any way. We clear the UPTODATE flag and then we can easily come in and try to read the EB while we're still waiting on other bio's to complete. We have two options here, we could lock all the pages, and then check to see if eb->io_pages != 0 to know if we've already got an outstanding write on the eb. Or we can simply check to see if we have WRITE_ERR set on this extent buffer. We set this bit _before_ we clear UPTODATE, so if the read gets triggered because we aren't UPTODATE because of a write error we're guaranteed to have WRITE_ERR set, and in this case we can simply return -EIO. This will fix the reported hang. Reported-by: Filipe Manana <fdmanana@suse.com> Fixes: c2e39305299f01 ("btrfs: clear extent buffer uptodate when we fail to write it") CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-12-15fanotify: wire up FAN_RENAME eventAmir Goldstein
FAN_RENAME is the successor of FAN_MOVED_FROM and FAN_MOVED_TO and can be used to get the old and new parent+name information in a single event. FAN_MOVED_FROM and FAN_MOVED_TO are still supported for backward compatibility, but it makes little sense to use them together with FAN_RENAME in the same group. FAN_RENAME uses special info type records to report the old and new parent+name, so reporting only old and new parent id is less useful and was not implemented. Therefore, FAN_REANAME requires a group with flag FAN_REPORT_NAME. Link: https://lore.kernel.org/r/20211129201537.1932819-12-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-12-15fanotify: report old and/or new parent+name in FAN_RENAME eventAmir Goldstein
In the special case of FAN_RENAME event, we report old or new or both old and new parent+name. A single info record will be reported if either the old or new dir is watched and two records will be reported if both old and new dir (or their filesystem) are watched. The old and new parent+name are reported using new info record types FAN_EVENT_INFO_TYPE_{OLD,NEW}_DFID_NAME, so if a single info record is reported, it is clear to the application, to which dir entry the fid+name info is referring to. Link: https://lore.kernel.org/r/20211129201537.1932819-11-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-12-15fanotify: record either old name new name or both for FAN_RENAMEAmir Goldstein
We do not want to report the dirfid+name of a directory whose inode/sb are not watched, because watcher may not have permissions to see the directory content. Use an internal iter_info to indicate to fanotify_alloc_event() which marks of this group are watching FAN_RENAME, so it can decide if we need to record only the old parent+name, new parent+name or both. Link: https://lore.kernel.org/r/20211129201537.1932819-10-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> [JK: Modified code to pass around only mask of mark types matching generated event] Signed-off-by: Jan Kara <jack@suse.cz>
2021-12-15fanotify: record old and new parent and name in FAN_RENAME eventAmir Goldstein
In the special case of FAN_RENAME event, we record both the old and new parent and name. Link: https://lore.kernel.org/r/20211129201537.1932819-9-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-12-15fanotify: support secondary dir fh and name in fanotify_infoAmir Goldstein
Allow storing a secondary dir fh and name tupple in fanotify_info. This will be used to store the new parent and name information in FAN_RENAME event. Link: https://lore.kernel.org/r/20211129201537.1932819-8-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-12-15fanotify: use helpers to parcel fanotify_info bufferAmir Goldstein
fanotify_info buffer is parceled into variable sized records, so the records must be written in order: dir_fh, file_fh, name. Use helpers to assert that order and make fanotify_alloc_name_event() a bit more generic to allow empty dir_fh record and to allow expanding to more records (i.e. name2) soon. Link: https://lore.kernel.org/r/20211129201537.1932819-7-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-12-15fanotify: use macros to get the offset to fanotify_info bufferAmir Goldstein
The fanotify_info buffer contains up to two file handles and a name. Use macros to simplify the code that access the different items within the buffer. Add assertions to verify that stored fh len and name len do not overflow the u8 stored value in fanotify_info header. Remove the unused fanotify_info_len() helper. Link: https://lore.kernel.org/r/20211129201537.1932819-6-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-12-15fsnotify: generate FS_RENAME event with rich informationAmir Goldstein
The dnotify FS_DN_RENAME event is used to request notification about a move within the same parent directory and was always coupled with the FS_MOVED_FROM event. Rename the FS_DN_RENAME event flag to FS_RENAME, decouple it from FS_MOVED_FROM and report it with the moved dentry instead of the moved inode, so it has the information about both old and new parent and name. Generate the FS_RENAME event regardless of same parent dir and apply the "same parent" rule in the generic fsnotify_handle_event() helper that is used to call backends with ->handle_inode_event() method (i.e. dnotify). The ->handle_inode_event() method is not rich enough to report both old and new parent and name anyway. The enriched event is reported to fanotify over the ->handle_event() method with the old and new dir inode marks in marks array slots for ITER_TYPE_INODE and a new iter type slot ITER_TYPE_INODE2. The enriched event will be used for reporting old and new parent+name to fanotify groups with FAN_RENAME events. Link: https://lore.kernel.org/r/20211129201537.1932819-5-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-12-15fanotify: introduce group flag FAN_REPORT_TARGET_FIDAmir Goldstein
FAN_REPORT_FID is ambiguous in that it reports the fid of the child for some events and the fid of the parent for create/delete/move events. The new FAN_REPORT_TARGET_FID flag is an implicit request to report the fid of the target object of the operation (a.k.a the child inode) also in create/delete/move events in addition to the fid of the parent and the name of the child. To reduce the test matrix for uninteresting use cases, the new FAN_REPORT_TARGET_FID flag requires both FAN_REPORT_NAME and FAN_REPORT_FID. The convenience macro FAN_REPORT_DFID_NAME_TARGET combines FAN_REPORT_TARGET_FID with all the required flags. Link: https://lore.kernel.org/r/20211129201537.1932819-4-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-12-15fsnotify: separate mark iterator type from object type enumAmir Goldstein
They are two different types that use the same enum, so this confusing. Use the object type to indicate the type of object mark is attached to and the iter type to indicate the type of watch. A group can have two different watches of the same object type (parent and child watches) that match the same event. Link: https://lore.kernel.org/r/20211129201537.1932819-3-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-12-15fsnotify: clarify object type argumentAmir Goldstein
In preparation for separating object type from iterator type, rename some 'type' arguments in functions to 'obj_type' and remove the unused interface to clear marks by object type mask. Link: https://lore.kernel.org/r/20211129201537.1932819-2-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2021-12-15udf: Fix error handling in udf_new_inode()Jan Kara
When memory allocation of iinfo or block allocation fails, already allocated struct udf_inode_info gets freed with iput() and udf_evict_inode() may look at inode fields which are not properly initialized. Fix it by marking inode bad before dropping reference to it in udf_new_inode(). Reported-by: syzbot+9ca499bb57a2b9e4c652@syzkaller.appspotmail.com Signed-off-by: Jan Kara <jack@suse.cz>
2021-12-14f2fs: compress: fix potential deadlock of compress fileHyeong-Jun Kim
There is a potential deadlock between writeback process and a process performing write_begin() or write_cache_pages() while trying to write same compress file, but not compressable, as below: [Process A] - doing checkpoint [Process B] [Process C] f2fs_write_cache_pages() - lock_page() [all pages in cluster, 0-31] - f2fs_write_multi_pages() - f2fs_write_raw_pages() - f2fs_write_single_data_page() - f2fs_do_write_data_page() - return -EAGAIN [f2fs_trylock_op() failed] - unlock_page(page) [e.g., page 0] - generic_perform_write() - f2fs_write_begin() - f2fs_prepare_compress_overwrite() - prepare_compress_overwrite() - lock_page() [e.g., page 0] - lock_page() [e.g., page 1] - lock_page(page) [e.g., page 0] Since there is no compress process, it is no longer necessary to hold locks on every pages in cluster within f2fs_write_raw_pages(). This patch changes f2fs_write_raw_pages() to release all locks first and then perform write same as the non-compress file in f2fs_write_cache_pages(). Fixes: 4c8ff7095bef ("f2fs: support data compression") Signed-off-by: Hyeong-Jun Kim <hj514.kim@samsung.com> Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Youngjin Gil <youngjin.gil@samsung.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-12-14f2fs: avoid EINVAL by SBI_NEED_FSCK when pinning a fileJaegeuk Kim
Android OTA failed due to SBI_NEED_FSCK flag when pinning the file. Let's avoid it since we can do in-place-updates. Cc: stable@vger.kernel.org Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2021-12-14btrfs: fix missing last dir item offset update when logging directoryFilipe Manana
When logging a directory, once we finish processing a leaf that is full of dir items, if we find the next leaf was not modified in the current transaction, we grab the first key of that next leaf and log it as to mark the end of a key range boundary. However we did not update the value of ctx->last_dir_item_offset, which tracks the offset of the last logged key. This can result in subsequent logging of the same directory in the current transaction to not realize that key was already logged, and then add it to the middle of a batch that starts with a lower key, resulting later in a leaf with one key that is duplicated and at non-consecutive slots. When that happens we get an error later when writing out the leaf, reporting that there is a pair of keys in wrong order. The report is something like the following: Dec 13 21:44:50 kernel: BTRFS critical (device dm-0): corrupt leaf: root=18446744073709551610 block=118444032 slot=21, bad key order, prev (704687 84 4146773349) current (704687 84 1063561078) Dec 13 21:44:50 kernel: BTRFS info (device dm-0): leaf 118444032 gen 91449 total ptrs 39 free space 546 owner 18446744073709551610 Dec 13 21:44:50 kernel: item 0 key (704687 1 0) itemoff 3835 itemsize 160 Dec 13 21:44:50 kernel: inode generation 35532 size 1026 mode 40755 Dec 13 21:44:50 kernel: item 1 key (704687 12 704685) itemoff 3822 itemsize 13 Dec 13 21:44:50 kernel: item 2 key (704687 24 3817753667) itemoff 3736 itemsize 86 Dec 13 21:44:50 kernel: item 3 key (704687 60 0) itemoff 3728 itemsize 8 Dec 13 21:44:50 kernel: item 4 key (704687 72 0) itemoff 3720 itemsize 8 Dec 13 21:44:50 kernel: item 5 key (704687 84 140445108) itemoff 3666 itemsize 54 Dec 13 21:44:50 kernel: dir oid 704793 type 1 Dec 13 21:44:50 kernel: item 6 key (704687 84 298800632) itemoff 3599 itemsize 67 Dec 13 21:44:50 kernel: dir oid 707849 type 2 Dec 13 21:44:50 kernel: item 7 key (704687 84 476147658) itemoff 3532 itemsize 67 Dec 13 21:44:50 kernel: dir oid 707901 type 2 Dec 13 21:44:50 kernel: item 8 key (704687 84 633818382) itemoff 3471 itemsize 61 Dec 13 21:44:50 kernel: dir oid 704694 type 2 Dec 13 21:44:50 kernel: item 9 key (704687 84 654256665) itemoff 3403 itemsize 68 Dec 13 21:44:50 kernel: dir oid 707841 type 1 Dec 13 21:44:50 kernel: item 10 key (704687 84 995843418) itemoff 3331 itemsize 72 Dec 13 21:44:50 kernel: dir oid 2167736 type 1 Dec 13 21:44:50 kernel: item 11 key (704687 84 1063561078) itemoff 3278 itemsize 53 Dec 13 21:44:50 kernel: dir oid 704799 type 2 Dec 13 21:44:50 kernel: item 12 key (704687 84 1101156010) itemoff 3225 itemsize 53 Dec 13 21:44:50 kernel: dir oid 704696 type 1 Dec 13 21:44:50 kernel: item 13 key (704687 84 2521936574) itemoff 3173 itemsize 52 Dec 13 21:44:50 kernel: dir oid 704704 type 2 Dec 13 21:44:50 kernel: item 14 key (704687 84 2618368432) itemoff 3112 itemsize 61 Dec 13 21:44:50 kernel: dir oid 704738 type 1 Dec 13 21:44:50 kernel: item 15 key (704687 84 2676316190) itemoff 3046 itemsize 66 Dec 13 21:44:50 kernel: dir oid 2167729 type 1 Dec 13 21:44:50 kernel: item 16 key (704687 84 3319104192) itemoff 2986 itemsize 60 Dec 13 21:44:50 kernel: dir oid 704745 type 2 Dec 13 21:44:50 kernel: item 17 key (704687 84 3908046265) itemoff 2929 itemsize 57 Dec 13 21:44:50 kernel: dir oid 2167734 type 1 Dec 13 21:44:50 kernel: item 18 key (704687 84 3945713089) itemoff 2857 itemsize 72 Dec 13 21:44:50 kernel: dir oid 2167730 type 1 Dec 13 21:44:50 kernel: item 19 key (704687 84 4077169308) itemoff 2795 itemsize 62 Dec 13 21:44:50 kernel: dir oid 704688 type 1 Dec 13 21:44:50 kernel: item 20 key (704687 84 4146773349) itemoff 2727 itemsize 68 Dec 13 21:44:50 kernel: dir oid 707892 type 1 Dec 13 21:44:50 kernel: item 21 key (704687 84 1063561078) itemoff 2674 itemsize 53 Dec 13 21:44:50 kernel: dir oid 704799 type 2 Dec 13 21:44:50 kernel: item 22 key (704687 96 2) itemoff 2612 itemsize 62 Dec 13 21:44:50 kernel: item 23 key (704687 96 6) itemoff 2551 itemsize 61 Dec 13 21:44:50 kernel: item 24 key (704687 96 7) itemoff 2498 itemsize 53 Dec 13 21:44:50 kernel: item 25 key (704687 96 12) itemoff 2446 itemsize 52 Dec 13 21:44:50 kernel: item 26 key (704687 96 14) itemoff 2385 itemsize 61 Dec 13 21:44:50 kernel: item 27 key (704687 96 18) itemoff 2325 itemsize 60 Dec 13 21:44:50 kernel: item 28 key (704687 96 24) itemoff 2271 itemsize 54 Dec 13 21:44:50 kernel: item 29 key (704687 96 28) itemoff 2218 itemsize 53 Dec 13 21:44:50 kernel: item 30 key (704687 96 62) itemoff 2150 itemsize 68 Dec 13 21:44:50 kernel: item 31 key (704687 96 66) itemoff 2083 itemsize 67 Dec 13 21:44:50 kernel: item 32 key (704687 96 75) itemoff 2015 itemsize 68 Dec 13 21:44:50 kernel: item 33 key (704687 96 79) itemoff 1948 itemsize 67 Dec 13 21:44:50 kernel: item 34 key (704687 96 82) itemoff 1882 itemsize 66 Dec 13 21:44:50 kernel: item 35 key (704687 96 83) itemoff 1810 itemsize 72 Dec 13 21:44:50 kernel: item 36 key (704687 96 85) itemoff 1753 itemsize 57 Dec 13 21:44:50 kernel: item 37 key (704687 96 87) itemoff 1681 itemsize 72 Dec 13 21:44:50 kernel: item 38 key (704694 1 0) itemoff 1521 itemsize 160 Dec 13 21:44:50 kernel: inode generation 35534 size 30 mode 40755 Dec 13 21:44:50 kernel: BTRFS error (device dm-0): block=118444032 write time tree block corruption detected So fix that by adding the missing update of ctx->last_dir_item_offset with the offset of the boundary key. Reported-by: Chris Murphy <lists@colorremedies.com> Link: https://lore.kernel.org/linux-btrfs/CAJCQCtT+RSzpUjbMq+UfzNUMe1X5+1G+DnAGbHC=OZ=iRS24jg@mail.gmail.com/ Fixes: dc2872247ec0ca ("btrfs: keep track of the last logged keys when logging a directory") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-12-14btrfs: fix double free of anon_dev after failure to create subvolumeFilipe Manana
When creating a subvolume, at create_subvol(), we allocate an anonymous device and later call btrfs_get_new_fs_root(), which in turn just calls btrfs_get_root_ref(). There we call btrfs_init_fs_root() which assigns the anonymous device to the root, but if after that call there's an error, when we jump to 'fail' label, we call btrfs_put_root(), which frees the anonymous device and then returns an error that is propagated back to create_subvol(). Than create_subvol() frees the anonymous device again. When this happens, if the anonymous device was not reallocated after the first time it was freed with btrfs_put_root(), we get a kernel message like the following: (...) [13950.282466] BTRFS: error (device dm-0) in create_subvol:663: errno=-5 IO failure [13950.283027] ida_free called for id=65 which is not allocated. [13950.285974] BTRFS info (device dm-0): forced readonly (...) If the anonymous device gets reallocated by another btrfs filesystem or any other kernel subsystem, then bad things can happen. So fix this by setting the root's anonymous device to 0 at btrfs_get_root_ref(), before we call btrfs_put_root(), if an error happened. Fixes: 2dfb1e43f57dd3 ("btrfs: preallocate anon block device at first phase of snapshot creation") CC: stable@vger.kernel.org # 5.10+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-12-14btrfs: fix memory leak in __add_inode_ref()Jianglei Nie
Line 1169 (#3) allocates a memory chunk for victim_name by kmalloc(), but when the function returns in line 1184 (#4) victim_name allocated by line 1169 (#3) is not freed, which will lead to a memory leak. There is a similar snippet of code in this function as allocating a memory chunk for victim_name in line 1104 (#1) as well as releasing the memory in line 1116 (#2). We should kfree() victim_name when the return value of backref_in_log() is less than zero and before the function returns in line 1184 (#4). 1057 static inline int __add_inode_ref(struct btrfs_trans_handle *trans, 1058 struct btrfs_root *root, 1059 struct btrfs_path *path, 1060 struct btrfs_root *log_root, 1061 struct btrfs_inode *dir, 1062 struct btrfs_inode *inode, 1063 u64 inode_objectid, u64 parent_objectid, 1064 u64 ref_index, char *name, int namelen, 1065 int *search_done) 1066 { 1104 victim_name = kmalloc(victim_name_len, GFP_NOFS); // #1: kmalloc (victim_name-1) 1105 if (!victim_name) 1106 return -ENOMEM; 1112 ret = backref_in_log(log_root, &search_key, 1113 parent_objectid, victim_name, 1114 victim_name_len); 1115 if (ret < 0) { 1116 kfree(victim_name); // #2: kfree (victim_name-1) 1117 return ret; 1118 } else if (!ret) { 1169 victim_name = kmalloc(victim_name_len, GFP_NOFS); // #3: kmalloc (victim_name-2) 1170 if (!victim_name) 1171 return -ENOMEM; 1180 ret = backref_in_log(log_root, &search_key, 1181 parent_objectid, victim_name, 1182 victim_name_len); 1183 if (ret < 0) { 1184 return ret; // #4: missing kfree (victim_name-2) 1185 } else if (!ret) { 1241 return 0; 1242 } Fixes: d3316c8233bb ("btrfs: Properly handle backref_in_log retval") CC: stable@vger.kernel.org # 5.10+ Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Jianglei Nie <niejianglei2021@163.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-12-14io_uring: code clean for some ctx usageHao Xu
There are some functions doing ctx = req->ctx while still using req->ctx, update those places. Signed-off-by: Hao Xu <haoxu@linux.alibaba.com> Link: https://lore.kernel.org/r/20211214055904.61772-1-haoxu@linux.alibaba.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-12-14fuse: mark inode DONT_CACHE when per inode DAX hint changesJeffle Xu
When the per inode DAX hint changes while the file is still *opened*, it is quite complicated and maybe fragile to dynamically change the DAX state. Hence mark the inode and corresponding dentries as DONE_CACHE once the per inode DAX hint changes, so that the inode instance will be evicted and freed as soon as possible once the file is closed and the last reference to the inode is put. And then when the file gets reopened next time, the new instantiated inode will reflect the new DAX state. In summary, when the per inode DAX hint changes for an *opened* file, the DAX state of the file won't be updated until this file is closed and reopened later. Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Reviewed-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-12-14fuse: negotiate per inode DAX in FUSE_INITJeffle Xu
Among the FUSE_INIT phase, client shall advertise per inode DAX if it's mounted with "dax=inode". Then server is aware that client is in per inode DAX mode, and will construct per-inode DAX attribute accordingly. Server shall also advertise support for per inode DAX. If server doesn't support it while client is mounted with "dax=inode", client will silently fallback to "dax=never" since "dax=inode" is advisory only. Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Reviewed-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-12-14fuse: enable per inode DAXJeffle Xu
DAX may be limited in some specific situation. When the number of usable DAX windows is under watermark, the recalim routine will be triggered to reclaim some DAX windows. It may have a negative impact on the performance, since some processes may need to wait for DAX windows to be recalimed and reused then. To mitigate the performance degradation, the overall DAX window need to be expanded larger. However, simply expanding the DAX window may not be a good deal in some scenario. To maintain one DAX window chunk (i.e., 2MB in size), 32KB (512 * 64 bytes) memory footprint will be consumed for page descriptors inside guest, which is greater than the memory footprint if it uses guest page cache when DAX disabled. Thus it'd better disable DAX for those files smaller than 32KB, to reduce the demand for DAX window and thus avoid the unworthy memory overhead. Per inode DAX feature is introduced to address this issue, by offering a finer grained control for dax to users, trying to achieve a balance between performance and memory overhead. The FUSE_ATTR_DAX flag in FUSE_LOOKUP reply is used to indicate whether DAX should be enabled or not for corresponding file. Currently the state whether DAX is enabled or not for the file is initialized only when inode is instantiated. Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Reviewed-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-12-14fuse: make DAX mount option a tri-stateJeffle Xu
We add 'always', 'never', and 'inode' (default). '-o dax' continues to operate the same which is equivalent to 'always'. The following behavior is consistent with that on ext4/xfs: - The default behavior (when neither '-o dax' nor '-o dax=always|never|inode' option is specified) is equal to 'inode' mode, while 'dax=inode' won't be printed among the mount option list. - The 'inode' mode is only advisory. It will silently fallback to 'never' mode if fuse server doesn't support that. Also noted that by the time of this commit, 'inode' mode is actually equal to 'always' mode, before the per inode DAX flag is introduced in the following patch. Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Reviewed-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-12-14fuse: add fuse_should_enable_dax() helperJeffle Xu
This is in prep for following per inode DAX checking. Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Reviewed-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-12-13fget: clarify and improve __fget_files() implementationLinus Torvalds
Commit 054aa8d439b9 ("fget: check that the fd still exists after getting a ref to it") fixed a race with getting a reference to a file just as it was being closed. It was a fairly minimal patch, and I didn't think re-checking the file pointer lookup would be a measurable overhead, since it was all right there and cached. But I was wrong, as pointed out by the kernel test robot. The 'poll2' case of the will-it-scale.per_thread_ops benchmark regressed quite noticeably. Admittedly it seems to be a very artificial test: doing "poll()" system calls on regular files in a very tight loop in multiple threads. That means that basically all the time is spent just looking up file descriptors without ever doing anything useful with them (not that doing 'poll()' on a regular file is useful to begin with). And as a result it shows the extra "re-check fd" cost as a sore thumb. Happily, the regression is fixable by just writing the code to loook up the fd to be better and clearer. There's still a cost to verify the file pointer, but now it's basically in the noise even for that benchmark that does nothing else - and the code is more understandable and has better comments too. [ Side note: this patch is also a classic case of one that looks very messy with the default greedy Myers diff - it's much more legible with either the patience of histogram diff algorithm ] Link: https://lore.kernel.org/lkml/20211210053743.GA36420@xsang-OptiPlex-9020/ Link: https://lore.kernel.org/lkml/20211213083154.GA20853@linux.intel.com/ Reported-by: kernel test robot <oliver.sang@intel.com> Tested-by: Carel Si <beibei.si@intel.com> Cc: Jann Horn <jannh@google.com> Cc: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-12-13NFSD: simplify per-net file cache managementNeilBrown
We currently have a 'laundrette' for closing cached files - a different work-item for each network-namespace. These 'laundrettes' (aka struct nfsd_fcache_disposal) are currently on a list, and are freed using rcu. The list is not necessary as we have a per-namespace structure (struct nfsd_net) which can hold a link to the nfsd_fcache_disposal. The use of kfree_rcu is also unnecessary as the cache is cleaned of all files associated with a given namespace, and no new files can be added, before the nfsd_fcache_disposal is freed. So add a '->fcache_disposal' link to nfsd_net, and discard the list management and rcu usage. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: Fix inconsistent indentingJiapeng Chong
Eliminate the follow smatch warning: fs/nfsd/nfs4xdr.c:4766 nfsd4_encode_read_plus_hole() warn: inconsistent indenting. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: Remove be32_to_cpu() from DRC hash functionChuck Lever
Commit 7142b98d9fd7 ("nfsd: Clean up drc cache in preparation for global spinlock elimination"), billed as a clean-up, added be32_to_cpu() to the DRC hash function without explanation. That commit removed two comments that state that byte-swapping in the hash function is unnecessary without explaining whether there was a need for that change. On some Intel CPUs, the swab32 instruction is known to cause a CPU pipeline stall. be32_to_cpu() does not add extra randomness, since the hash multiplication is done /before/ shifting to the high-order bits of the result. As a micro-optimization, remove the unnecessary transform from the DRC hash function. Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFS: switch the callback service back to non-pooled.NeilBrown
Now that thread management is consistent there is no need for nfs-callback to use svc_create_pooled() as introduced in Commit df807fffaabd ("NFSv4.x/callback: Create the callback service through svc_create_pooled"). So switch back to svc_create(). If service pools were configured, but the number of threads were left at '1', nfs callback may not work reliably when svc_create_pooled() is used. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13lockd: use svc_set_num_threads() for thread start and stopNeilBrown
svc_set_num_threads() does everything that lockd_start_svc() does, except set sv_maxconn. It also (when passed 0) finds the threads and stops them with kthread_stop(). So move the setting for sv_maxconn, and use svc_set_num_thread() We now don't need nlmsvc_task. Now that we use svc_set_num_threads() it makes sense to set svo_module. This request that the thread exists with module_put_and_exit(). Also fix the documentation for svo_module to make this explicit. svc_prepare_thread is now only used where it is defined, so it can be made static. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13lockd: rename lockd_create_svc() to lockd_get()NeilBrown
lockd_create_svc() already does an svc_get() if the service already exists, so it is more like a "get" than a "create". So: - Move the increment of nlmsvc_users into the function as well - rename to lockd_get(). It is now the inverse of lockd_put(). Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13lockd: introduce lockd_put()NeilBrown
There is some cleanup that is duplicated in lockd_down() and the failure path of lockd_up(). Factor these out into a new lockd_put() and call it from both places. lockd_put() does *not* take the mutex - that must be held by the caller. It decrements nlmsvc_users and if that reaches zero, it cleans up. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13lockd: move svc_exit_thread() into the threadNeilBrown
The normal place to call svc_exit_thread() is from the thread itself just before it exists. Do this for lockd. This means that nlmsvc_rqst is not used out side of lockd_start_svc(), so it can be made local to that function, and renamed to 'rqst'. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13lockd: move lockd_start_svc() call into lockd_create_svc()NeilBrown
lockd_start_svc() only needs to be called once, just after the svc is created. If the start fails, the svc is discarded too. It thus makes sense to call lockd_start_svc() from lockd_create_svc(). This allows us to remove the test against nlmsvc_rqst at the start of lockd_start_svc() - it must always be NULL. lockd_up() only held an extra reference on the svc until a thread was created - then it dropped it. The thread - and thus the extra reference - will remain until kthread_stop() is called. Now that the thread is created in lockd_create_svc(), the extra reference can be dropped there. So the 'serv' variable is no longer needed in lockd_up(). Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13lockd: simplify management of network status notifiersNeilBrown
Now that the network status notifiers use nlmsvc_serv rather then nlmsvc_rqst the management can be simplified. Notifier unregistration synchronises with any pending notifications so providing we unregister before nlm_serv is freed no further interlock is required. So we move the unregister call to just before the thread is killed (which destroys the service) and just before the service is destroyed in the failure-path of lockd_up(). Then nlm_ntf_refcnt and nlm_ntf_wq can be removed. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13lockd: introduce nlmsvc_servNeilBrown
lockd has two globals - nlmsvc_task and nlmsvc_rqst - but mostly it wants the 'struct svc_serv', and when it doesn't want it exactly it can get to what it wants from the serv. This patch is a first step to removing nlmsvc_task and nlmsvc_rqst. It introduces nlmsvc_serv to store the 'struct svc_serv*'. This is set as soon as the serv is created, and cleared only when it is destroyed. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: simplify locking for network notifier.NeilBrown
nfsd currently maintains an open-coded read/write semaphore (refcount and wait queue) for each network namespace to ensure the nfs service isn't shut down while the notifier is running. This is excessive. As there is unlikely to be contention between notifiers and they run without sleeping, a single spinlock is sufficient to avoid problems. Signed-off-by: NeilBrown <neilb@suse.de> [ cel: ensure nfsd_notifier_lock is static ] Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: discard svo_setup and rename svc_set_num_threads_sync()NeilBrown
The ->svo_setup callback serves no purpose. It is always called from within the same module that chooses which callback is needed. So discard it and call the relevant function directly. Now that svc_set_num_threads() is no longer used remove it and rename svc_set_num_threads_sync() to remove the "_sync" suffix. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: Make it possible to use svc_set_num_threads_syncNeilBrown
nfsd cannot currently use svc_set_num_threads_sync. It instead uses svc_set_num_threads which does *not* wait for threads to all exit, and has a separate mechanism (nfsd_shutdown_complete) to wait for completion. The reason that nfsd is unlike other services is that nfsd threads can exit separately from svc_set_num_threads being called - they die on receipt of SIGKILL. Also, when the last thread exits, the service must be shut down (sockets closed). For this, the nfsd_mutex needs to be taken, and as that mutex needs to be held while svc_set_num_threads is called, the one cannot wait for the other. This patch changes the nfsd thread so that it can drop the ref on the service without blocking on nfsd_mutex, so that svc_set_num_threads_sync can be used: - if it can drop a non-last reference, it does that. This does not trigger shutdown and does not require a mutex. This will likely happen for all but the last thread signalled, and for all threads being shut down by nfsd_shutdown_threads() - if it can get the mutex without blocking (trylock), it does that and then drops the reference. This will likely happen for the last thread killed by SIGKILL - Otherwise there might be an unrelated task holding the mutex, possibly in another network namespace, or nfsd_shutdown_threads() might be just about to get a reference on the service, after which we can drop ours safely. We cannot conveniently get wakeup notifications on these events, and we are unlikely to need to, so we sleep briefly and check again. With this we can discard nfsd_shutdown_complete and nfsd_complete_shutdown(), and switch to svc_set_num_threads_sync. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: narrow nfsd_mutex protection in nfsd threadNeilBrown
There is nothing happening in the start of nfsd() that requires protection by the mutex, so don't take it until shutting down the thread - which does still require protection - but only for nfsd_put(). Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: use sv_lock to protect updates to sv_nrthreads.NeilBrown
Using sv_lock means we don't need to hold the service mutex over these updates. In particular, svc_exit_thread() no longer requires synchronisation, so threads can exit asynchronously. Note that we could use an atomic_t, but as there are many more read sites than writes, that would add unnecessary noise to the code. Some reads are already racy, and there is no need for them to not be. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13nfsd: make nfsd_stats.th_cnt atomic_tNeilBrown
This allows us to move the updates for th_cnt out of the mutex. This is a step towards reducing mutex coverage in nfsd(). Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: stop using ->sv_nrthreads as a refcountNeilBrown
The use of sv_nrthreads as a general refcount results in clumsy code, as is seen by various comments needed to explain the situation. This patch introduces a 'struct kref' and uses that for reference counting, leaving sv_nrthreads to be a pure count of threads. The kref is managed particularly in svc_get() and svc_put(), and also nfsd_put(); svc_destroy() now takes a pointer to the embedded kref, rather than to the serv. nfsd allows the svc_serv to exist with ->sv_nrhtreads being zero. This happens when a transport is created before the first thread is started. To support this, a 'keep_active' flag is introduced which holds a ref on the svc_serv. This is set when any listening socket is successfully added (unless there are running threads), and cleared when the number of threads is set. So when the last thread exits, the nfs_serv will be destroyed. The use of 'keep_active' replaces previous code which checked if there were any permanent sockets. We no longer clear ->rq_server when nfsd() exits. This was done to prevent svc_exit_thread() from calling svc_destroy(). Instead we take an extra reference to the svc_serv to prevent svc_destroy() from being called. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC/NFSD: clean up get/put functions.NeilBrown
svc_destroy() is poorly named - it doesn't necessarily destroy the svc, it might just reduce the ref count. nfsd_destroy() is poorly named for the same reason. This patch: - removes the refcount functionality from svc_destroy(), moving it to a new svc_put(). Almost all previous callers of svc_destroy() now call svc_put(). - renames nfsd_destroy() to nfsd_put() and improves the code, using the new svc_destroy() rather than svc_put() - removes a few comments that explain the important for balanced get/put calls. This should be obvious. The only non-trivial part of this is that svc_destroy() would call svc_sock_update() on a non-final decrement. It can no longer do that, and svc_put() isn't really a good place of it. This call is now made from svc_exit_thread() which seems like a good place. This makes the call *before* sv_nrthreads is decremented rather than after. This is not particularly important as the call just sets a flag which causes sv_nrthreads set be checked later. A subsequent patch will improve the ordering. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13SUNRPC: change svc_get() to return the svc.NeilBrown
It is common for 'get' functions to return the object that was 'got', and there are a couple of places where users of svc_get() would be a little simpler if svc_get() did that. Make it so. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: handle errors better in write_ports_addfd()NeilBrown
If write_ports_add() fails, we shouldn't destroy the serv, unless we had only just created it. So if there are any permanent sockets already attached, leave the serv in place. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-12-13NFSD: Fix sparse warningChuck Lever
/home/cel/src/linux/linux/fs/nfsd/nfs4proc.c:1539:24: warning: incorrect type in assignment (different base types) /home/cel/src/linux/linux/fs/nfsd/nfs4proc.c:1539:24: expected restricted __be32 [usertype] status /home/cel/src/linux/linux/fs/nfsd/nfs4proc.c:1539:24: got int Signed-off-by: Chuck Lever <chuck.lever@oracle.com>