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2019-11-22xfs: improve the xfs_dabuf_map calling conventionsChristoph Hellwig
Use a flags argument with the XFS_DABUF_MAP_HOLE_OK flag to signal that a hole is okay and not corruption, and return 0 with *nmap set to 0 to signal that case in the return value instead of a nameless -1 return code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-11-22xfs: refactor xfs_dabuf_mapChristoph Hellwig
Merge xfs_buf_map_from_irec and xfs_da_map_covers_blocks into a single loop in the caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-11-22xfs: simplify mappedbno handling in xfs_da_{get,read}_bufChristoph Hellwig
Shortcut the creation of xfs_bmbt_irec and xfs_buf_map for the case where the callers passed an already mapped xfs_daddr_t. This is in preparation for splitting these cases out entirely later. Also reject the mappedbno case for xfs_da_reada_buf as no callers currently uses it and it will be removed soon. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-11-22virtiofs: Use completions while waiting for queue to be drainedVivek Goyal
While we wait for queue to finish draining, use completions instead of usleep_range(). This is better way of waiting for event. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-11-22virtiofs: Do not send forget request "struct list_head" elementVivek Goyal
We are sending whole of virtio_fs_forget struct to the other end over virtqueue. Other end does not need to see elements like "struct list". That's internal detail of guest kernel. Fix it. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-11-22virtiofs: Use a common function to send forgetVivek Goyal
Currently we are duplicating logic to send forgets at two places. Consolidate the code by calling one helper function. This also uses virtqueue_add_outbuf() instead of virtqueue_add_sgs(). Former is simpler to call. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2019-11-21afs: Remove set but not used variable 'ret'zhengbin
Fixes gcc '-Wunused-but-set-variable' warning: fs/afs/server.c: In function afs_install_server: fs/afs/server.c:157:6: warning: variable ret set but not used [-Wunused-but-set-variable] It is not used since commit d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: David Howells <dhowells@redhat.com>
2019-11-21afs: Remove set but not used variables 'before', 'after'zhengbin
Fixes gcc '-Wunused-but-set-variable' warning: fs/afs/dir_edit.c: In function afs_set_contig_bits: fs/afs/dir_edit.c:75:20: warning: variable after set but not used [-Wunused-but-set-variable] fs/afs/dir_edit.c: In function afs_set_contig_bits: fs/afs/dir_edit.c:75:12: warning: variable before set but not used [-Wunused-but-set-variable] fs/afs/dir_edit.c: In function afs_clear_contig_bits: fs/afs/dir_edit.c:100:20: warning: variable after set but not used [-Wunused-but-set-variable] fs/afs/dir_edit.c: In function afs_clear_contig_bits: fs/afs/dir_edit.c:100:12: warning: variable before set but not used [-Wunused-but-set-variable] They are never used since commit 63a4681ff39c. Fixes: 63a4681ff39c ("afs: Locally edit directory data for mkdir/create/unlink/...") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: zhengbin <zhengbin13@huawei.com> Signed-off-by: David Howells <dhowells@redhat.com>
2019-11-21gfs2: Don't write log headers after file system withdrawBob Peterson
Before this patch, when a node withdrew a gfs2 file system, it wrote a (clean) unmount log header. That's wrong. You don't want to write anything to the journal once you're withdrawn because that's acknowledging that the transaction is complete and the journal is in good shape, neither of which may be a valid assumption when the file system is withdrawn. This is especially true if the withdraw was caused due to io errors writing to the journal in the first place. The best course of action is to leave the journal "as is" until it may be safely replayed during journal recovery, regardless of whether it's done by this node or another. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2019-11-21gfs2: Remove duplicate call from gfs2_create_inodeAndreas Gruenbacher
In gfs2_create_inode, gfs2_set_inode_blocks is called twice for no good reason. Remove the unnecessary call. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2019-11-21afs: xattr: use scnprintfMark Salyzyn
sprintf and snprintf are fragile in future maintenance, switch to using scnprintf to ensure no accidental Use After Free conditions are introduced. Signed-off-by: Mark Salyzyn <salyzyn@android.com> Cc: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: David Howells <dhowells@redhat.com> Cc: linux-afs@lists.infradead.org Cc: Jan Kara <jack@suse.cz> Signed-off-by: David Howells <dhowells@redhat.com>
2019-11-21afs: Introduce an afs_get_read() refcount helperDavid Howells
Introduce an afs_get_read() helper to get a reference on an afs_read object. Signed-off-by: David Howells <dhowells@redhat.com>
2019-11-21afs: Rename desc -> req in afs_fetch_data()David Howells
Rename the desc parameter to req in afs_fetch_data() for consistency with other functions. Signed-off-by: David Howells <dhowells@redhat.com>
2019-11-21afs: Switch the naming of call->iter and call->_iterDavid Howells
Change the name of call->iter to call->def_iter to represent the default iterator. Change the name of call->_iter to call->iter to represent the iterator actually being used. Signed-off-by: David Howells <dhowells@redhat.com>
2019-11-21afs: Use call->_iter not &call->iter in debugging statementsDavid Howells
Use call->_iter not &call->iter in debugging statements as the latter is a convenience iter whereas the former represents we're actually doing at the moment. Signed-off-by: David Howells <dhowells@redhat.com>
2019-11-21procfs: Use all-in-one vtime aware kcpustat accessorFrederic Weisbecker
Now that we can read also user and guest time safely under vtime, use the relevant accessor to fix frozen kcpustat values on nohz_full CPUs. Reported-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wanpeng Li <wanpengli@tencent.com> Link: https://lkml.kernel.org/r/20191121024430.19938-4-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-11-20exit/exec: Seperate mm_release()Thomas Gleixner
mm_release() contains the futex exit handling. mm_release() is called from do_exit()->exit_mm() and from exec()->exec_mm(). In the exit_mm() case PF_EXITING and the futex state is updated. In the exec_mm() case these states are not touched. As the futex exit code needs further protections against exit races, this needs to be split into two functions. Preparatory only, no functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20191106224556.240518241@linutronix.de
2019-11-19nfsd: restore NFSv3 ACL supportJ. Bruce Fields
An error in e333f3bbefe3 left the nfsd_acl_program->pg_vers array empty, which effectively turned off the server's support for NFSv3 ACLs. Fixes: e333f3bbefe3 "nfsd: Allow containers to set supported nfs versions" Cc: stable@vger.kernel.org Cc: Trond Myklebust <trondmy@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-11-19f2fs: Fix deadlock in f2fs_gc() context during atomic files handlingSahitya Tummala
The FS got stuck in the below stack when the storage is almost full/dirty condition (when FG_GC is being done). schedule_timeout io_schedule_timeout congestion_wait f2fs_drop_inmem_pages_all f2fs_gc f2fs_balance_fs __write_node_page f2fs_fsync_node_pages f2fs_do_sync_file f2fs_ioctl The root cause for this issue is there is a potential infinite loop in f2fs_drop_inmem_pages_all() for the case where gc_failure is true and when there an inode whose i_gc_failures[GC_FAILURE_ATOMIC] is not set. Fix this by keeping track of the total atomic files currently opened and using that to exit from this condition. Fix-suggested-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Sahitya Tummala <stummala@codeaurora.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2019-11-19f2fs: show f2fs instance in printk_ratelimitedChao Yu
As Eric mentioned, bare printk{,_ratelimited} won't show which filesystem instance these message is coming from, this patch tries to show fs instance with sb->s_id field in all places we missed before. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2019-11-19afs: Fix missing timeout resetDavid Howells
In afs_wait_for_call_to_complete(), rather than immediately aborting an operation if a signal occurs, the code attempts to wait for it to complete, using a schedule timeout of 2*RTT (or min 2 jiffies) and a check that we're still receiving relevant packets from the server before we consider aborting the call. We may even ping the server to check on the status of the call. However, there's a missing timeout reset in the event that we do actually get a packet to process, such that if we then get a couple of short stalls, we then time out when progress is actually being made. Fix this by resetting the timeout any time we get something to process. If it's the failure of the call then the call state will get changed and we'll exit the loop shortly thereafter. A symptom of this is data fetches and stores failing with EINTR when they really shouldn't. Fixes: bc5e3a546d55 ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals") Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-11-19gfs2: clean up iopen glock mess in gfs2_create_inodeBob Peterson
Before this patch, gfs2_create_inode had a use-after-free for the iopen glock in some error paths because it did this: gfs2_glock_put(io_gl); fail_gunlock2: if (io_gl) clear_bit(GLF_INODE_CREATING, &io_gl->gl_flags); In some cases, the io_gl was used for create and only had one reference, so the glock might be freed before the clear_bit(). This patch tries to straighten it out by only jumping to the error paths where iopen is properly set, and moving the gfs2_glock_put after the clear_bit. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2019-11-19Merge branch 'tt/misc' into devTheodore Ts'o
2019-11-19ext4: work around deleting a file with i_nlink == 0 safelyTheodore Ts'o
If the file system is corrupted such that a file's i_links_count is too small, then it's possible that when unlinking that file, i_nlink will already be zero. Previously we were working around this kind of corruption by forcing i_nlink to one; but we were doing this before trying to delete the directory entry --- and if the file system is corrupted enough that ext4_delete_entry() fails, then we exit with i_nlink elevated, and this causes the orphan inode list handling to be FUBAR'ed, such that when we unmount the file system, the orphan inode list can get corrupted. A better way to fix this is to simply skip trying to call drop_nlink() if i_nlink is already zero, thus moving the check to the place where it makes the most sense. https://bugzilla.kernel.org/show_bug.cgi?id=205433 Link: https://lore.kernel.org/r/20191112032903.8828-1-tytso@mit.edu Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Reviewed-by: Andreas Dilger <adilger@dilger.ca>
2019-11-19ext4: add more paranoia checking in ext4_expand_extra_isize handlingTheodore Ts'o
It's possible to specify a non-zero s_want_extra_isize via debugging option, and this can cause bad things(tm) to happen when using a file system with an inode size of 128 bytes. Add better checking when the file system is mounted, as well as when we are actually doing the trying to do the inode expansion. Link: https://lore.kernel.org/r/20191110121510.GH23325@mit.edu Reported-by: syzbot+f8d6f8386ceacdbfff57@syzkaller.appspotmail.com Reported-by: syzbot+33d7ea72e47de3bdf4e1@syzkaller.appspotmail.com Reported-by: syzbot+44b6763edfc17144296f@syzkaller.appspotmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org
2019-11-19ext2: code cleanup for descriptor_loc()Chengguang Xu
Code cleanup by removing unnecessary variable in descriptor_loc(). Link: https://lore.kernel.org/r/20191115224900.2613-1-cgxu519@mykernel.net Signed-off-by: Chengguang Xu <cgxu519@mykernel.net> Signed-off-by: Jan Kara <jack@suse.cz>
2019-11-18btrfs: drop bdev argument from submit_extent_pageDavid Sterba
After previous patches removing bdev being passed around to set it to bio, it has become unused in submit_extent_page. So it now has "only" 13 parameters. Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: remove extent_map::bdevDavid Sterba
We can now remove the bdev from extent_map. Previous patches made sure that bio_set_dev is correctly in all places and that we don't need to grab it from latest_bdev or pass it around inside the extent map. Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: drop bio_set_dev where not neededDavid Sterba
bio_set_dev sets a bdev to a bio and is not only setting a pointer bug also changing some state bits if there was a different bdev set before. This is one thing that's not needed. Another thing is that setting a bdev at bio allocation time is too early and actually does not work with plain redundancy profiles, where each time we submit a bio to a device, the bdev is set correctly. In many places the bio bdev is set to latest_bdev that seems to serve as a stub pointer "just to put something to bio". But we don't have to do that. Where do we know which bdev to set: * for regular IO: submit_stripe_bio that's called by btrfs_map_bio * repair IO: repair_io_failure, read or write from specific device * super block write (using buffer_heads but uses raw bdev) and barriers * scrub: this does not use all regular IO paths as it needs to reach all copies, verify and fixup eventually, and for that all bdev management is independent * raid56: rbio_add_io_page, for the RMW write * integrity-checker: does it's own low-level block tracking Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: get bdev directly from fs_devices in submit_extent_pageDavid Sterba
This is preparatory patch to remove @bdev parameter from submit_extent_page. It can't be removed completely, because the cgroups need it for wbc when initializing the bio wbc_init_bio bio_associate_blkg_from_css dereference bdev->bi_disk->queue The bdev pointer is the same as latest_bdev, thus no functional change. We can retrieve it from fs_devices that's reachable through several dereferences. The local variable shadows the parameter, but that's only temporary. Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: record all roots for rename exchange on a subvolJosef Bacik
Testing with the new fsstress support for subvolumes uncovered a pretty bad problem with rename exchange on subvolumes. We're modifying two different subvolumes, but we only start the transaction on one of them, so the other one is not added to the dirty root list. This is caught by btrfs_cow_block() with a warning because the root has not been updated, however if we do not modify this root again we'll end up pointing at an invalid root because the root item is never updated. Fix this by making sure we add the destination root to the trans list, the same as we do with normal renames. This fixes the corruption. Fixes: cdd1fedf8261 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT") CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18Btrfs: fix block group remaining RO forever after error during device replaceFilipe Manana
When doing a device replace, while at scrub.c:scrub_enumerate_chunks(), we set the block group to RO mode and then wait for any ongoing writes into extents of the block group to complete. While doing that wait we overwrite the value of the variable 'ret' and can break out of the loop if an error happens without turning the block group back into RW mode. So what happens is the following: 1) btrfs_inc_block_group_ro() returns 0, meaning it set the block group to RO mode (its ->ro field set to 1 or incremented to some value > 1); 2) Then btrfs_wait_ordered_roots() returns a value > 0; 3) Then if either joining or committing the transaction fails, we break out of the loop wihtout calling btrfs_dec_block_group_ro(), leaving the block group in RO mode forever. To fix this, just remove the code that waits for ongoing writes to extents of the block group, since it's not needed because in the initial setup phase of a device replace operation, before starting to find all chunks and their extents, we set the target device for replace while holding fs_info->dev_replace->rwsem, which ensures that after releasing that semaphore, any writes into the source device are made to the target device as well (__btrfs_map_block() guarantees that). So while at scrub_enumerate_chunks() we only need to worry about finding and copying extents (from the source device to the target device) that were written before we started the device replace operation. Fixes: f0e9b7d6401959 ("Btrfs: fix race setting block group readonly during device replace") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: scrub: Don't check free space before marking a block group ROQu Wenruo
[BUG] When running btrfs/072 with only one online CPU, it has a pretty high chance to fail: btrfs/072 12s ... _check_dmesg: something found in dmesg (see xfstests-dev/results//btrfs/072.dmesg) - output mismatch (see xfstests-dev/results//btrfs/072.out.bad) --- tests/btrfs/072.out 2019-10-22 15:18:14.008965340 +0800 +++ /xfstests-dev/results//btrfs/072.out.bad 2019-11-14 15:56:45.877152240 +0800 @@ -1,2 +1,3 @@ QA output created by 072 Silence is golden +Scrub find errors in "-m dup -d single" test ... And with the following call trace: BTRFS info (device dm-5): scrub: started on devid 1 ------------[ cut here ]------------ BTRFS: Transaction aborted (error -27) WARNING: CPU: 0 PID: 55087 at fs/btrfs/block-group.c:1890 btrfs_create_pending_block_groups+0x3e6/0x470 [btrfs] CPU: 0 PID: 55087 Comm: btrfs Tainted: G W O 5.4.0-rc1-custom+ #13 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:btrfs_create_pending_block_groups+0x3e6/0x470 [btrfs] Call Trace: __btrfs_end_transaction+0xdb/0x310 [btrfs] btrfs_end_transaction+0x10/0x20 [btrfs] btrfs_inc_block_group_ro+0x1c9/0x210 [btrfs] scrub_enumerate_chunks+0x264/0x940 [btrfs] btrfs_scrub_dev+0x45c/0x8f0 [btrfs] btrfs_ioctl+0x31a1/0x3fb0 [btrfs] do_vfs_ioctl+0x636/0xaa0 ksys_ioctl+0x67/0x90 __x64_sys_ioctl+0x43/0x50 do_syscall_64+0x79/0xe0 entry_SYSCALL_64_after_hwframe+0x49/0xbe ---[ end trace 166c865cec7688e7 ]--- [CAUSE] The error number -27 is -EFBIG, returned from the following call chain: btrfs_end_transaction() |- __btrfs_end_transaction() |- btrfs_create_pending_block_groups() |- btrfs_finish_chunk_alloc() |- btrfs_add_system_chunk() This happens because we have used up all space of btrfs_super_block::sys_chunk_array. The root cause is, we have the following bad loop of creating tons of system chunks: 1. The only SYSTEM chunk is being scrubbed It's very common to have only one SYSTEM chunk. 2. New SYSTEM bg will be allocated As btrfs_inc_block_group_ro() will check if we have enough space after marking current bg RO. If not, then allocate a new chunk. 3. New SYSTEM bg is still empty, will be reclaimed During the reclaim, we will mark it RO again. 4. That newly allocated empty SYSTEM bg get scrubbed We go back to step 2, as the bg is already mark RO but still not cleaned up yet. If the cleaner kthread doesn't get executed fast enough (e.g. only one CPU), then we will get more and more empty SYSTEM chunks, using up all the space of btrfs_super_block::sys_chunk_array. [FIX] Since scrub/dev-replace doesn't always need to allocate new extent, especially chunk tree extent, so we don't really need to do chunk pre-allocation. To break above spiral, here we introduce a new parameter to btrfs_inc_block_group(), @do_chunk_alloc, which indicates whether we need extra chunk pre-allocation. For relocation, we pass @do_chunk_alloc=true, while for scrub, we pass @do_chunk_alloc=false. This should keep unnecessary empty chunks from popping up for scrub. Also, since there are two parameters for btrfs_inc_block_group_ro(), add more comment for it. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: change btrfs_fs_devices::rotating to boolJohannes Thumshirn
struct btrfs_fs_devices::rotating currently is declared as an integer variable but only used as a boolean. Change the variable definition to bool and update to code touching it to set 'true' and 'false'. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: change btrfs_fs_devices::seeding to boolJohannes Thumshirn
struct btrfs_fs_devices::seeding currently is declared as an integer variable but only used as a boolean. Change the variable definition to bool and update to code touching it to set 'true' and 'false'. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: rename btrfs_block_group_cacheDavid Sterba
The type name is misleading, a single entry is named 'cache' while this normally means a collection of objects. Rename that everywhere. Also the identifier was quite long, making function prototypes harder to format. Suggested-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: block-group: Reuse the item key from caller of read_one_block_group()Qu Wenruo
For read_one_block_group(), its only caller has already got the item key to search next block group item. So we can use that key directly without doing our own convertion on stack. Also, since that key used in btrfs_read_block_groups() is vital for block group item search, add 'const' keyword for that parameter to prevent read_one_block_group() to modify it. Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: block-group: Refactor btrfs_read_block_groups()Qu Wenruo
Refactor the work inside the loop of btrfs_read_block_groups() into one separate function, read_one_block_group(). This allows read_one_block_group to be reused for later BG_TREE feature. The refactor does the following extra fix: - Use btrfs_fs_incompat() to replace open-coded feature check Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: document extent buffer lockingDavid Sterba
Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: access eb::blocking_writers according to ACCESS_ONCE policiesDavid Sterba
A nice writeup of the LKMM (Linux Kernel Memory Model) rules for access once policies can be found here https://lwn.net/Articles/799218/#Access-Marking%20Policies . The locked and unlocked access to eb::blocking_writers should be annotated accordingly, following this: Writes: - locked write must use ONCE, may use plain read - unlocked write must use ONCE Reads: - unlocked read must use ONCE - locked read may use plain read iff not mixed with unlocked read - unlocked read then locked must use ONCE There's one difference on the assembly level, where btrfs_tree_read_lock_atomic and btrfs_try_tree_read_lock used the cached value and did not reevaluate it after taking the lock. This could have missed some opportunities to take the lock in case blocking writers changed between the calls, but the window is just a few instructions long. As this is in try-lock, the callers handle that. Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: set blocking_writers directly, no increment or decrementDavid Sterba
The increment and decrement was inherited from previous version that used atomics, switched in commit 06297d8cefca ("btrfs: switch extent_buffer blocking_writers from atomic to int"). The only possible values are 0 and 1 so we can set them directly. The generated assembly (gcc 9.x) did the direct value assignment in btrfs_set_lock_blocking_write (asm diff after change in 06297d8cefca): 5d: test %eax,%eax 5f: je 62 <btrfs_set_lock_blocking_write+0x22> 61: retq - 62: lock incl 0x44(%rdi) - 66: add $0x50,%rdi - 6a: jmpq 6f <btrfs_set_lock_blocking_write+0x2f> + 62: movl $0x1,0x44(%rdi) + 69: add $0x50,%rdi + 6d: jmpq 72 <btrfs_set_lock_blocking_write+0x32> The part in btrfs_tree_unlock did a decrement because BUG_ON(blockers > 1) is probably not a strong hint for the compiler, but otherwise the output looks safe: - lock decl 0x44(%rdi) + sub $0x1,%eax + mov %eax,0x44(%rdi) Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: merge blocking_writers branches in btrfs_tree_read_lockDavid Sterba
There are two ifs that use eb::blocking_writers. As this is a variable modified inside and outside of locks, we could minimize number of accesses to avoid problems with getting different results at different times. The access here is locked so this can only race with btrfs_tree_unlock that sets blocking_writers to 0 without lock and unsets the lock owner. The first branch is taken only if the same thread already holds the lock, the second if checks for blocking writers. Here we'd either unlock and wait, or proceed. Both are valid states of the locking protocol. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: drop incompat bit for raid1c34 after last block group is goneDavid Sterba
When there are no raid1c3 or raid1c4 block groups left after balance (either convert or with other filters applied), remove the incompat bit. This is already done for RAID56, do the same for RAID1C34. Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: add incompat for raid1 with 3, 4 copiesDavid Sterba
The new raid1c3 and raid1c4 profiles are backward incompatible and the name shall be 'raid1c34', the status can be found in the global supported features in /sys/fs/btrfs/features or in the per-filesystem directory. Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: add support for 4-copy replication (raid1c4)David Sterba
Add new block group profile to store 4 copies in a simliar way that current RAID1 does. The profile attributes and constraints are defined in the raid table and used by the same code that already handles the 2- and 3-copy RAID1. The minimum number of devices is 4, the maximum number of devices/chunks that can be lost/damaged is 3. There is no comparable traditional RAID level, the profile is added for future needs to accompany triple-parity and beyond. Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: add support for 3-copy replication (raid1c3)David Sterba
Add new block group profile to store 3 copies in a simliar way that current RAID1 does. The profile attributes and constraints are defined in the raid table and used by the same code that already handles the 2-copy RAID1. The minimum number of devices is 3, the maximum number of devices/chunks that can be lost/damaged is 2. Like RAID6 but with 33% space utilization. Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: sink write flags to cow_file_range_asyncDavid Sterba
In commit "Btrfs: use REQ_CGROUP_PUNT for worker thread submitted bios", cow_file_range_async gained wbc as a parameter and this makes passing write flags redundant. Set it inside the function and remove the parameter. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18btrfs: sink write_flags to __extent_writepage_ioDavid Sterba
__extent_writepage reads write flags from wbc and passes both to __extent_writepage_io. This makes write_flags redundant and we can remove it. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18Btrfs: send, skip backreference walking for extents with many referencesFilipe Manana
Backreference walking, which is used by send to figure if it can issue clone operations instead of write operations, can be very slow and use too much memory when extents have many references. This change simply skips backreference walking when an extent has more than 64 references, in which case we fallback to a write operation instead of a clone operation. This limit is conservative and in practice I observed no signicant slowdown with up to 100 references and still low memory usage up to that limit. This is a temporary workaround until there are speedups in the backref walking code, and as such it does not attempt to add extra interfaces or knobs to tweak the threshold. Reported-by: Atemu <atemu.main@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CAE4GHgkvqVADtS4AzcQJxo0Q1jKQgKaW3JGp3SGdoinVo=C9eQ@mail.gmail.com/T/#me55dc0987f9cc2acaa54372ce0492c65782be3fa CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-11-18Btrfs: send, allow clone operations within the same fileFilipe Manana
For send we currently skip clone operations when the source and destination files are the same. This is so because clone didn't support this case in its early days, but support for it was added back in May 2013 by commit a96fbc72884fcb ("Btrfs: allow file data clone within a file"). This change adds support for it. Example: $ mkfs.btrfs -f /dev/sdd $ mount /dev/sdd /mnt/sdd $ xfs_io -f -c "pwrite -S 0xab -b 64K 0 64K" /mnt/sdd/foobar $ xfs_io -c "reflink /mnt/sdd/foobar 0 64K 64K" /mnt/sdd/foobar $ btrfs subvolume snapshot -r /mnt/sdd /mnt/sdd/snap $ mkfs.btrfs -f /dev/sde $ mount /dev/sde /mnt/sde $ btrfs send /mnt/sdd/snap | btrfs receive /mnt/sde Without this change file foobar at the destination has a single 128Kb extent: $ filefrag -v /mnt/sde/snap/foobar Filesystem type is: 9123683e File size of /mnt/sde/snap/foobar is 131072 (32 blocks of 4096 bytes) ext: logical_offset: physical_offset: length: expected: flags: 0: 0.. 31: 0.. 31: 32: last,unknown_loc,delalloc,eof /mnt/sde/snap/foobar: 1 extent found With this we get a single 64Kb extent that is shared at file offsets 0 and 64K, just like in the source filesystem: $ filefrag -v /mnt/sde/snap/foobar Filesystem type is: 9123683e File size of /mnt/sde/snap/foobar is 131072 (32 blocks of 4096 bytes) ext: logical_offset: physical_offset: length: expected: flags: 0: 0.. 15: 3328.. 3343: 16: shared 1: 16.. 31: 3328.. 3343: 16: 3344: last,shared,eof /mnt/sde/snap/foobar: 2 extents found Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>