linux.git/fs/f2fs/dir.c, branch v5.17 Linux kernel source tree unicode: clean up the Kconfig symbol confusion 2022-01-21T00:57:24+00:00 Christoph Hellwig hch@lst.de 2022-01-18T06:56:14+00:00 5298d4bfe80f6ae6ae2777bcd1357b0022d98573 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 <torvalds@linux-foundation.org> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> 
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 <torvalds@linux-foundation.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
f2fs: support fault injection for f2fs_kmem_cache_alloc() 2021-08-17T18:59:05+00:00 Chao Yu chao@kernel.org 2021-08-09T00:24:48+00:00 324105775c1982aacbd2972b7024d8cc06474abe This patch supports to inject fault into f2fs_kmem_cache_alloc(). Usage: a) echo 32768 > /sys/fs/f2fs/<dev>/inject_type or b) mount -o fault_type=32768 <dev> <mountpoint> Signed-off-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
This patch supports to inject fault into f2fs_kmem_cache_alloc().

Usage:
a) echo 32768 > /sys/fs/f2fs/<dev>/inject_type or
b) mount -o fault_type=32768 <dev> <mountpoint>

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs: reduce the scope of setting fsck tag when de->name_len is zero 2021-08-04T22:51:21+00:00 Yangtao Li frank.li@vivo.com 2021-08-04T03:29:46+00:00 d4bf15a7ce172d186d400d606adf4f34a59130d6 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 <frank.li@vivo.com> [Chao: clean up description] Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
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 <frank.li@vivo.com>
[Chao: clean up description]
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs: introduce f2fs_casefolded_name slab cache 2021-06-23T08:09:35+00:00 Chao Yu yuchao0@huawei.com 2021-06-10T23:46:30+00:00 4d9a2bb1a6babc9280a8b4e7a95ada9bf6e51e9a Add a slab cache: "f2fs_casefolded_name" for memory allocation of casefold name. Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
Add a slab cache: "f2fs_casefolded_name" for memory allocation
of casefold name.

Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs: restructure f2fs page.private layout 2021-05-14T18:22:08+00:00 Chao Yu yuchao0@huawei.com 2021-04-28T09:20:31+00:00 b763f3bedc2da2edf81bba550430847f561eae0e 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 <willy@infradead.org> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
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 <willy@infradead.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
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 Linus Torvalds torvalds@linux-foundation.org 2021-05-05T01:03:38+00:00 d0195c7d7af6a456c37f4b4b2df5528f10714482 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 ... 
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 Al Viro viro@zeniv.linux.org.uk 2021-04-15T23:46:50+00:00 80e5d1ff5d5f1ed5167a69b7c2fe86071b615f6b Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> 
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
f2fs: clean up build warnings 2021-04-10T17:36:39+00:00 Yi Zhuang zhuangyi1@huawei.com 2021-04-06T01:47:35+00:00 5f029c045c948b6cb8ccfda614e73240c4a8363b This patch combined the below three clean-up patches. - modify open brace '{' following function definitions - ERROR: spaces required around that ':' - ERROR: spaces required before the open parenthesis '(' - ERROR: spaces prohibited before that ',' - Made suggested modifications from checkpatch in reference to WARNING: Missing a blank line after declarations Signed-off-by: Yi Zhuang <zhuangyi1@huawei.com> Signed-off-by: Jia Yang <jiayang5@huawei.com> Signed-off-by: Jack Qiu <jack.qiu@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
This patch combined the below three clean-up patches.

- modify open brace '{' following function definitions
- ERROR: spaces required around that ':'
- ERROR: spaces required before the open parenthesis '('
- ERROR: spaces prohibited before that ','
- Made suggested modifications from checkpatch in reference to WARNING:
 Missing a blank line after declarations

Signed-off-by: Yi Zhuang <zhuangyi1@huawei.com>
Signed-off-by: Jia Yang <jiayang5@huawei.com>
Signed-off-by: Jack Qiu <jack.qiu@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Merge tag 'f2fs-for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs 2020-12-17T19:18:00+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-12-17T19:18:00+00:00 ff49c86f27e4726a86f5034543e6e684daf41955 Pull f2fs updates from Jaegeuk Kim: "In this round, we've made more work into per-file compression support. For example, F2FS_IOC_GET | SET_COMPRESS_OPTION provides a way to change the algorithm or cluster size per file. F2FS_IOC_COMPRESS | DECOMPRESS_FILE provides a way to compress and decompress the existing normal files manually. There is also a new mount option, compress_mode=fs|user, which can control who compresses the data. Chao also added a checksum feature with a mount option so that we are able to detect any corrupted cluster. In addition, Daniel contributed casefolding with encryption patch, which will be used for Android devices. Summary: Enhancements: - add ioctls and mount option to manage per-file compression feature - support casefolding with encryption - support checksum for compressed cluster - avoid IO starvation by replacing mutex with rwsem - add sysfs, max_io_bytes, to control max bio size Bug fixes: - fix use-after-free issue when compression and fsverity are enabled - fix consistency corruption during fault injection test - fix data offset for lseek - get rid of buffer_head which has 32bits limit in fiemap - fix some bugs in multi-partitions support - fix nat entry count calculation in shrinker - fix some stat information And, we've refactored some logics and fix minor bugs as well" * tag 'f2fs-for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (36 commits) f2fs: compress: fix compression chksum f2fs: fix shift-out-of-bounds in sanity_check_raw_super() f2fs: fix race of pending_pages in decompression f2fs: fix to account inline xattr correctly during recovery f2fs: inline: fix wrong inline inode stat f2fs: inline: correct comment in f2fs_recover_inline_data f2fs: don't check PAGE_SIZE again in sanity_check_raw_super() f2fs: convert to F2FS_*_INO macro f2fs: introduce max_io_bytes, a sysfs entry, to limit bio size f2fs: don't allow any writes on readonly mount f2fs: avoid race condition for shrinker count f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE f2fs: add compress_mode mount option f2fs: Remove unnecessary unlikely() f2fs: init dirty_secmap incorrectly f2fs: remove buffer_head which has 32bits limit f2fs: fix wrong block count instead of bytes f2fs: use new conversion functions between blks and bytes f2fs: rename logical_to_blk and blk_to_logical f2fs: fix kbytes written stat for multi-device case ... 
Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've made more work into per-file compression support.

  For example, F2FS_IOC_GET | SET_COMPRESS_OPTION provides a way to
  change the algorithm or cluster size per file. F2FS_IOC_COMPRESS |
  DECOMPRESS_FILE provides a way to compress and decompress the existing
  normal files manually.

  There is also a new mount option, compress_mode=fs|user, which can
  control who compresses the data.

  Chao also added a checksum feature with a mount option so that
  we are able to detect any corrupted cluster.

  In addition, Daniel contributed casefolding with encryption patch,
  which will be used for Android devices.

  Summary:

  Enhancements:
   - add ioctls and mount option to manage per-file compression feature
   - support casefolding with encryption
   - support checksum for compressed cluster
   - avoid IO starvation by replacing mutex with rwsem
   - add sysfs, max_io_bytes, to control max bio size

  Bug fixes:
   - fix use-after-free issue when compression and fsverity are enabled
   - fix consistency corruption during fault injection test
   - fix data offset for lseek
   - get rid of buffer_head which has 32bits limit in fiemap
   - fix some bugs in multi-partitions support
   - fix nat entry count calculation in shrinker
   - fix some stat information

  And, we've refactored some logics and fix minor bugs as well"

* tag 'f2fs-for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (36 commits)
  f2fs: compress: fix compression chksum
  f2fs: fix shift-out-of-bounds in sanity_check_raw_super()
  f2fs: fix race of pending_pages in decompression
  f2fs: fix to account inline xattr correctly during recovery
  f2fs: inline: fix wrong inline inode stat
  f2fs: inline: correct comment in f2fs_recover_inline_data
  f2fs: don't check PAGE_SIZE again in sanity_check_raw_super()
  f2fs: convert to F2FS_*_INO macro
  f2fs: introduce max_io_bytes, a sysfs entry, to limit bio size
  f2fs: don't allow any writes on readonly mount
  f2fs: avoid race condition for shrinker count
  f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE
  f2fs: add compress_mode mount option
  f2fs: Remove unnecessary unlikely()
  f2fs: init dirty_secmap incorrectly
  f2fs: remove buffer_head which has 32bits limit
  f2fs: fix wrong block count instead of bytes
  f2fs: use new conversion functions between blks and bytes
  f2fs: rename logical_to_blk and blk_to_logical
  f2fs: fix kbytes written stat for multi-device case
  ...
f2fs: Handle casefolding with Encryption 2020-12-03T06:00:21+00:00 Daniel Rosenberg drosen@google.com 2020-11-19T06:09:04+00:00 7ad08a58bf67594057362e45cbddd3e27e53e557 Expand f2fs's casefolding support to include encrypted directories. To index casefolded+encrypted directories, we use the SipHash of the casefolded name, keyed by a key derived from the directory's fscrypt master key. This ensures that the dirhash doesn't leak information about the plaintext filenames. Encryption keys are unavailable during roll-forward recovery, so we can't compute the dirhash when recovering a new dentry in an encrypted + casefolded directory. To avoid having to force a checkpoint when a new file is fsync'ed, store the dirhash on-disk appended to i_name. This patch incorporates work by Eric Biggers <ebiggers@google.com> and Jaegeuk Kim <jaegeuk@kernel.org>. Co-developed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Daniel Rosenberg <drosen@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
Expand f2fs's casefolding support to include encrypted directories.  To
index casefolded+encrypted directories, we use the SipHash of the
casefolded name, keyed by a key derived from the directory's fscrypt
master key.  This ensures that the dirhash doesn't leak information
about the plaintext filenames.

Encryption keys are unavailable during roll-forward recovery, so we
can't compute the dirhash when recovering a new dentry in an encrypted +
casefolded directory.  To avoid having to force a checkpoint when a new
file is fsync'ed, store the dirhash on-disk appended to i_name.

This patch incorporates work by Eric Biggers <ebiggers@google.com>
and Jaegeuk Kim <jaegeuk@kernel.org>.

Co-developed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>