kernel/linux.git/fs/f2fs/dir.c, branch linux-6.0.y

f2fs: don't use casefolded comparison for "." and ".."

2022-05-17T18:19:23+00:00

Tryng to rename a directory that has all following properties fails with EINVAL and triggers the 'WARN_ON_ONCE(!fscrypt_has_encryption_key(dir))' in f2fs_match_ci_name(): - The directory is casefolded - The directory is encrypted - The directory's encryption key is not yet set up - The parent directory is *not* encrypted The problem is incorrect handling of the lookup of ".." to get the parent reference to update. fscrypt_setup_filename() treats ".." (and ".") specially, as it's never encrypted. It's passed through as-is, and setting up the directory's key is not attempted. As the name isn't a no-key name, f2fs treats it as a "normal" name and attempts a casefolded comparison. That breaks the assumption of the WARN_ON_ONCE() in f2fs_match_ci_name() which assumes that for encrypted directories, casefolded comparisons only happen when the directory's key is set up. We could just remove this WARN_ON_ONCE(). However, since casefolding is always a no-op on "." and ".." anyway, let's instead just not casefold these names. This results in the standard bytewise comparison. Fixes: 7ad08a58bf67 ("f2fs: Handle casefolding with Encryption") Cc: # v5.11+ Signed-off-by: Eric Biggers Reviewed-by: Gabriel Krisman Bertazi Signed-off-by: Jaegeuk Kim

Merge tag 'f2fs-for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

2022-03-22T17:00:31+00:00

Pull f2fs updates from Jaegeuk Kim: "In this cycle, f2fs has some performance improvements for Android workloads such as using read-unfair rwsems and adding some sysfs entries to control GCs and discard commands in more details. In addtiion, it has some tunings to improve the recovery speed after sudden power-cut. Enhancement: - add reader-unfair rwsems with F2FS_UNFAIR_RWSEM: will replace with generic API support - adjust to make the readahead/recovery flow more efficiently - sysfs entries to control issue speeds of GCs and Discard commands - enable idmapped mounts Bug fix: - correct wrong error handling routines - fix missing conditions in quota - fix a potential deadlock between writeback and block plug routines - fix a deadlock btween freezefs and evict_inode We've added some boundary checks to avoid kernel panics on corrupted images, and several minor code clean-ups" * tag 'f2fs-for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (27 commits) f2fs: fix to do sanity check on .cp_pack_total_block_count f2fs: make gc_urgent and gc_segment_mode sysfs node readable f2fs: use aggressive GC policy during f2fs_disable_checkpoint() f2fs: fix compressed file start atomic write may cause data corruption f2fs: initialize sbi->gc_mode explicitly f2fs: introduce gc_urgent_mid mode f2fs: compress: fix to print raw data size in error path of lz4 decompression f2fs: remove redundant parameter judgment f2fs: use spin_lock to avoid hang f2fs: don't get FREEZE lock in f2fs_evict_inode in frozen fs f2fs: remove unnecessary read for F2FS_FITS_IN_INODE f2fs: introduce F2FS_UNFAIR_RWSEM to support unfair rwsem f2fs: avoid an infinite loop in f2fs_sync_dirty_inodes f2fs: fix to do sanity check on curseg->alloc_type f2fs: fix to avoid potential deadlock f2fs: quota: fix loop condition at f2fs_quota_sync() f2fs: Restore rwsem lockdep support f2fs: fix missing free nid in f2fs_handle_failed_inode f2fs: support idmapped mounts f2fs: add a way to limit roll forward recovery time ...

f2fs: move f2fs to use reader-unfair rwsems

2022-01-25T01:40:04+00:00

f2fs rw_semaphores work better if writers can starve readers, especially for the checkpoint thread, because writers are strictly more important than reader threads. This prevents significant priority inversion between low-priority readers that blocked while trying to acquire the read lock and a second acquisition of the write lock that might be blocking high priority work. Signed-off-by: Tim Murray Signed-off-by: Jaegeuk Kim

unicode: clean up the Kconfig symbol confusion

2022-01-21T00:57:24+00:00

Turn the CONFIG_UNICODE symbol into a tristate that generates some always built in code and remove the confusing CONFIG_UNICODE_UTF8_DATA symbol. Note that a lot of the IS_ENABLED() checks could be turned from cpp statements into normal ifs, but this change is intended to be fairly mechanic, so that should be cleaned up later. Fixes: 2b3d04787012 ("unicode: Add utf8-data module") Reported-by: Linus Torvalds Reviewed-by: Eric Biggers Signed-off-by: Christoph Hellwig Signed-off-by: Gabriel Krisman Bertazi

f2fs: support fault injection for f2fs_kmem_cache_alloc()

2021-08-17T18:59:05+00:00

This patch supports to inject fault into f2fs_kmem_cache_alloc(). Usage: a) echo 32768 > /sys/fs/f2fs//inject_type or b) mount -o fault_type=32768 Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: reduce the scope of setting fsck tag when de->name_len is zero

2021-08-04T22:51:21+00:00

I recently found a case where de->name_len is 0 in f2fs_fill_dentries() easily reproduced, and finally set the fsck flag. Thread A Thread B - f2fs_readdir - f2fs_read_inline_dir - ctx->pos = d.max - f2fs_add_dentry - f2fs_add_inline_entry - do_convert_inline_dir - f2fs_add_regular_entry - f2fs_readdir - f2fs_fill_dentries - set_sbi_flag(sbi, SBI_NEED_FSCK) Process A opens the folder, and has been reading without closing it. During this period, Process B created a file under the folder (occupying multiple f2fs_dir_entry, exceeding the d.max of the inline dir). After creation, process A uses the d.max of inline dir to read it again, and it will read that de->name_len is 0. And Chao pointed out that w/o inline conversion, the race condition still can happen as below: dir_entry1: A dir_entry2: B dir_entry3: C free slot: _ ctx->pos: ^ Thread A is traversing directory, ctx-pos moves to below position after readdir() by thread A: AAAABBBB___ ^ Then thread B delete dir_entry2, and create dir_entry3. Thread A calls readdir() to lookup dirents starting from middle of new dirent slots as below: AAAACCCCCC_ ^ In these scenarios, the file system is not damaged, and it's hard to avoid it. But we can bypass tagging FSCK flag if: a) bit_pos (:= ctx->pos % d->max) is non-zero and b) before bit_pos moves to first valid dir_entry. Fixes: ddf06b753a85 ("f2fs: fix to trigger fsck if dirent.name_len is zero") Signed-off-by: Yangtao Li [Chao: clean up description] Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: introduce f2fs_casefolded_name slab cache

2021-06-23T08:09:35+00:00

Add a slab cache: "f2fs_casefolded_name" for memory allocation of casefold name. Reviewed-by: Eric Biggers Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: restructure f2fs page.private layout

2021-05-14T18:22:08+00:00

Restruct f2fs page private layout for below reasons: There are some cases that f2fs wants to set a flag in a page to indicate a specified status of page: a) page is in transaction list for atomic write b) page contains dummy data for aligned write c) page is migrating for GC d) page contains inline data for inline inode flush e) page belongs to merkle tree, and is verified for fsverity f) page is dirty and has filesystem/inode reference count for writeback g) page is temporary and has decompress io context reference for compression There are existed places in page structure we can use to store f2fs private status/data: - page.flags: PG_checked, PG_private - page.private However it was a mess when we using them, which may cause potential confliction: page.private PG_private PG_checked page._refcount (+1 at most) a) -1 set +1 b) -2 set c), d), e) set f) 0 set +1 g) pointer set The other problem is page.flags has no free slot, if we can avoid set zero to page.private and set PG_private flag, then we use non-zero value to indicate PG_private status, so that we may have chance to reclaim PG_private slot for other usage. [1] The other concern is f2fs has bad scalability in aspect of indicating more page status. So in this patch, let's restructure f2fs' page.private as below to solve above issues: Layout A: lowest bit should be 1 | bit0 = 1 | bit1 | bit2 | ... | bit MAX | private data .... | bit 0 PAGE_PRIVATE_NOT_POINTER bit 1 PAGE_PRIVATE_ATOMIC_WRITE bit 2 PAGE_PRIVATE_DUMMY_WRITE bit 3 PAGE_PRIVATE_ONGOING_MIGRATION bit 4 PAGE_PRIVATE_INLINE_INODE bit 5 PAGE_PRIVATE_REF_RESOURCE bit 6- f2fs private data Layout B: lowest bit should be 0 page.private is a wrapped pointer. After the change: page.private PG_private PG_checked page._refcount (+1 at most) a) 11 set +1 b) 101 set +1 c) 1001 set +1 d) 10001 set +1 e) set f) 100001 set +1 g) pointer set +1 [1] https://lore.kernel.org/linux-f2fs-devel/20210422154705.GO3596236@casper.infradead.org/T/#u Cc: Matthew Wilcox Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

Merge tag 'f2fs-for-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

2021-05-05T01:03:38+00:00

Pull f2fs updates from Jaegeuk Kim: "In this round, we added a new mount option, "checkpoint_merge", which introduces a kernel thread dealing with the f2fs checkpoints. Once we start to manage the IO priority along with blk-cgroup, the checkpoint operation can be processed in a lower priority under the process context. Since the checkpoint holds all the filesystem operations, we give a higher priority to the checkpoint thread all the time. Enhancements: - introduce gc_merge mount option to introduce a checkpoint thread - improve to run discard thread efficiently - allow modular compression algorithms - expose # of overprivision segments to sysfs - expose runtime compression stat to sysfs Bug fixes: - fix OOB memory access by the node id lookup - avoid touching checkpointed data in the checkpoint-disabled mode - fix the resizing flow to avoid kernel panic and race conditions - fix block allocation issues on pinned files - address some swapfile issues - fix hugtask problem and kernel panic during atomic write operations - don't start checkpoint thread in RO And, we've cleaned up some kernel coding style and build warnings. In addition, we fixed some minor race conditions and error handling routines" * tag 'f2fs-for-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (48 commits) f2fs: drop inplace IO if fs status is abnormal f2fs: compress: remove unneed check condition f2fs: clean up left deprecated IO trace codes f2fs: avoid using native allocate_segment_by_default() f2fs: remove unnecessary struct declaration f2fs: fix to avoid NULL pointer dereference f2fs: avoid duplicated codes for cleanup f2fs: document: add description about compressed space handling f2fs: clean up build warnings f2fs: fix the periodic wakeups of discard thread f2fs: fix to avoid accessing invalid fio in f2fs_allocate_data_block() f2fs: fix to avoid GC/mmap race with f2fs_truncate() f2fs: set checkpoint_merge by default f2fs: Fix a hungtask problem in atomic write f2fs: fix to restrict mount condition on readonly block device f2fs: introduce gc_merge mount option f2fs: fix to cover __allocate_new_section() with curseg_lock f2fs: fix wrong alloc_type in f2fs_do_replace_block f2fs: delete empty compress.h f2fs: fix a typo in inode.c ...

useful constants: struct qstr for ".."

2021-04-16T02:36:45+00:00

Signed-off-by: Al Viro