linux.git/fs/f2fs/dir.c, branch v5.12 Linux kernel source tree 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>
fscrypt: Have filesystems handle their d_ops 2020-12-03T06:00:21+00:00 Daniel Rosenberg drosen@google.com 2020-11-19T06:09:03+00:00 bb9cd9106b22b4fc5ff8d78a752be8a4ba2cbba5 This shifts the responsibility of setting up dentry operations from fscrypt to the individual filesystems, allowing them to have their own operations while still setting fscrypt's d_revalidate as appropriate. Most filesystems can just use generic_set_encrypted_ci_d_ops, unless they have their own specific dentry operations as well. That operation will set the minimal d_ops required under the circumstances. Since the fscrypt d_ops are set later on, we must set all d_ops there, since we cannot adjust those later on. This should not result in any change in behavior. Signed-off-by: Daniel Rosenberg <drosen@google.com> Acked-by: Theodore Ts'o <tytso@mit.edu> Acked-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
This shifts the responsibility of setting up dentry operations from
fscrypt to the individual filesystems, allowing them to have their own
operations while still setting fscrypt's d_revalidate as appropriate.

Most filesystems can just use generic_set_encrypted_ci_d_ops, unless
they have their own specific dentry operations as well. That operation
will set the minimal d_ops required under the circumstances.

Since the fscrypt d_ops are set later on, we must set all d_ops there,
since we cannot adjust those later on. This should not result in any
change in behavior.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
fscrypt: introduce fscrypt_prepare_readdir() 2020-12-03T02:25:01+00:00 Eric Biggers ebiggers@google.com 2020-12-03T02:20:37+00:00 ec0caa974cd092549ab282deb8ec7ea73b36eba0 The last remaining use of fscrypt_get_encryption_info() from filesystems is for readdir (->iterate_shared()). Every other call is now in fs/crypto/ as part of some other higher-level operation. We need to add a new argument to fscrypt_get_encryption_info() to indicate whether the encryption policy is allowed to be unrecognized or not. Doing this is easier if we can work with high-level operations rather than direct filesystem use of fscrypt_get_encryption_info(). So add a function fscrypt_prepare_readdir() which wraps the call to fscrypt_get_encryption_info() for the readdir use case. Reviewed-by: Andreas Dilger <adilger@dilger.ca> Link: https://lore.kernel.org/r/20201203022041.230976-6-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> 
The last remaining use of fscrypt_get_encryption_info() from filesystems
is for readdir (->iterate_shared()).  Every other call is now in
fs/crypto/ as part of some other higher-level operation.

We need to add a new argument to fscrypt_get_encryption_info() to
indicate whether the encryption policy is allowed to be unrecognized or
not.  Doing this is easier if we can work with high-level operations
rather than direct filesystem use of fscrypt_get_encryption_info().

So add a function fscrypt_prepare_readdir() which wraps the call to
fscrypt_get_encryption_info() for the readdir use case.

Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/20201203022041.230976-6-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
f2fs: remove f2fs_dir_open() 2020-12-03T02:25:01+00:00 Eric Biggers ebiggers@google.com 2020-12-03T02:20:34+00:00 73114b6d28727b3f98b6a673c54c64b2c46ce4f5 Since encrypted directories can be opened and searched without their key being available, and each readdir and ->lookup() tries to set up the key, trying to set up the key in ->open() too isn't really useful. Just remove it so that directories don't need an ->open() method anymore, and so that we eliminate a use of fscrypt_get_encryption_info() (which I'd like to stop exporting to filesystems). Reviewed-by: Chao Yu <yuchao0@huawei.com> Link: https://lore.kernel.org/r/20201203022041.230976-3-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> 
Since encrypted directories can be opened and searched without their key
being available, and each readdir and ->lookup() tries to set up the
key, trying to set up the key in ->open() too isn't really useful.

Just remove it so that directories don't need an ->open() method
anymore, and so that we eliminate a use of fscrypt_get_encryption_info()
(which I'd like to stop exporting to filesystems).

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20201203022041.230976-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Merge tag 'f2fs-for-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs 2020-10-16T22:14:43+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-10-16T22:14:43+00:00 7a3dadedc82e340f8292f64e7bfa964c525009c0 Pull f2fs updates from Jaegeuk Kim: "In this round, we've added new features such as zone capacity for ZNS and a new GC policy, ATGC, along with in-memory segment management. In addition, we could improve the decompression speed significantly by changing virtual mapping method. Even though we've fixed lots of small bugs in compression support, I feel that it becomes more stable so that I could give it a try in production. Enhancements: - suport zone capacity in NVMe Zoned Namespace devices - introduce in-memory current segment management - add standart casefolding support - support age threshold based garbage collection - improve decompression speed by changing virtual mapping method Bug fixes: - fix condition checks in some ioctl() such as compression, move_range, etc - fix 32/64bits support in data structures - fix memory allocation in zstd decompress - add some boundary checks to avoid kernel panic on corrupted image - fix disallowing compression for non-empty file - fix slab leakage of compressed block writes In addition, it includes code refactoring for better readability and minor bug fixes for compression and zoned device support" * tag 'f2fs-for-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (51 commits) f2fs: code cleanup by removing unnecessary check f2fs: wait for sysfs kobject removal before freeing f2fs_sb_info f2fs: fix writecount false positive in releasing compress blocks f2fs: introduce check_swap_activate_fast() f2fs: don't issue flush in f2fs_flush_device_cache() for nobarrier case f2fs: handle errors of f2fs_get_meta_page_nofail f2fs: fix to set SBI_NEED_FSCK flag for inconsistent inode f2fs: reject CASEFOLD inode flag without casefold feature f2fs: fix memory alignment to support 32bit f2fs: fix slab leak of rpages pointer f2fs: compress: fix to disallow enabling compress on non-empty file f2fs: compress: introduce cic/dic slab cache f2fs: compress: introduce page array slab cache f2fs: fix to do sanity check on segment/section count f2fs: fix to check segment boundary during SIT page readahead f2fs: fix uninit-value in f2fs_lookup f2fs: remove unneeded parameter in find_in_block() f2fs: fix wrong total_sections check and fsmeta check f2fs: remove duplicated code in sanity_check_area_boundary f2fs: remove unused check on version_bitmap ... 
Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've added new features such as zone capacity for ZNS
  and a new GC policy, ATGC, along with in-memory segment management. In
  addition, we could improve the decompression speed significantly by
  changing virtual mapping method. Even though we've fixed lots of small
  bugs in compression support, I feel that it becomes more stable so
  that I could give it a try in production.

  Enhancements:
   - suport zone capacity in NVMe Zoned Namespace devices
   - introduce in-memory current segment management
   - add standart casefolding support
   - support age threshold based garbage collection
   - improve decompression speed by changing virtual mapping method

  Bug fixes:
   - fix condition checks in some ioctl() such as compression, move_range, etc
   - fix 32/64bits support in data structures
   - fix memory allocation in zstd decompress
   - add some boundary checks to avoid kernel panic on corrupted image
   - fix disallowing compression for non-empty file
   - fix slab leakage of compressed block writes

  In addition, it includes code refactoring for better readability and
  minor bug fixes for compression and zoned device support"

* tag 'f2fs-for-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (51 commits)
  f2fs: code cleanup by removing unnecessary check
  f2fs: wait for sysfs kobject removal before freeing f2fs_sb_info
  f2fs: fix writecount false positive in releasing compress blocks
  f2fs: introduce check_swap_activate_fast()
  f2fs: don't issue flush in f2fs_flush_device_cache() for nobarrier case
  f2fs: handle errors of f2fs_get_meta_page_nofail
  f2fs: fix to set SBI_NEED_FSCK flag for inconsistent inode
  f2fs: reject CASEFOLD inode flag without casefold feature
  f2fs: fix memory alignment to support 32bit
  f2fs: fix slab leak of rpages pointer
  f2fs: compress: fix to disallow enabling compress on non-empty file
  f2fs: compress: introduce cic/dic slab cache
  f2fs: compress: introduce page array slab cache
  f2fs: fix to do sanity check on segment/section count
  f2fs: fix to check segment boundary during SIT page readahead
  f2fs: fix uninit-value in f2fs_lookup
  f2fs: remove unneeded parameter in find_in_block()
  f2fs: fix wrong total_sections check and fsmeta check
  f2fs: remove duplicated code in sanity_check_area_boundary
  f2fs: remove unused check on version_bitmap
  ...
f2fs: fix uninit-value in f2fs_lookup 2020-09-29T09:12:41+00:00 Chao Yu yuchao0@huawei.com 2020-09-29T01:22:50+00:00 6d7ab88a98c1b7a47c228f8ffb4f44d631eaf284 As syzbot reported: Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x21c/0x280 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:122 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:219 f2fs_lookup+0xe05/0x1a80 fs/f2fs/namei.c:503 lookup_open fs/namei.c:3082 [inline] open_last_lookups fs/namei.c:3177 [inline] path_openat+0x2729/0x6a90 fs/namei.c:3365 do_filp_open+0x2b8/0x710 fs/namei.c:3395 do_sys_openat2+0xa88/0x1140 fs/open.c:1168 do_sys_open fs/open.c:1184 [inline] __do_compat_sys_openat fs/open.c:1242 [inline] __se_compat_sys_openat+0x2a4/0x310 fs/open.c:1240 __ia32_compat_sys_openat+0x56/0x70 fs/open.c:1240 do_syscall_32_irqs_on arch/x86/entry/common.c:80 [inline] __do_fast_syscall_32+0x129/0x180 arch/x86/entry/common.c:139 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:162 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:205 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c In f2fs_lookup(), @res_page could be used before being initialized, because in __f2fs_find_entry(), once F2FS_I(dir)->i_current_depth was been fuzzed to zero, then @res_page will never be initialized, causing this kmsan warning, relocating @res_page initialization place to fix this bug. Reported-by: syzbot+0eac6f0bbd558fd866d7@syzkaller.appspotmail.com Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
As syzbot reported:

Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:122
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:219
 f2fs_lookup+0xe05/0x1a80 fs/f2fs/namei.c:503
 lookup_open fs/namei.c:3082 [inline]
 open_last_lookups fs/namei.c:3177 [inline]
 path_openat+0x2729/0x6a90 fs/namei.c:3365
 do_filp_open+0x2b8/0x710 fs/namei.c:3395
 do_sys_openat2+0xa88/0x1140 fs/open.c:1168
 do_sys_open fs/open.c:1184 [inline]
 __do_compat_sys_openat fs/open.c:1242 [inline]
 __se_compat_sys_openat+0x2a4/0x310 fs/open.c:1240
 __ia32_compat_sys_openat+0x56/0x70 fs/open.c:1240
 do_syscall_32_irqs_on arch/x86/entry/common.c:80 [inline]
 __do_fast_syscall_32+0x129/0x180 arch/x86/entry/common.c:139
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:162
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:205
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

In f2fs_lookup(), @res_page could be used before being initialized,
because in __f2fs_find_entry(), once F2FS_I(dir)->i_current_depth was
been fuzzed to zero, then @res_page will never be initialized, causing
this kmsan warning, relocating @res_page initialization place to fix
this bug.

Reported-by: syzbot+0eac6f0bbd558fd866d7@syzkaller.appspotmail.com
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs: remove unneeded parameter in find_in_block() 2020-09-29T08:48:34+00:00 Chao Yu yuchao0@huawei.com 2020-09-26T00:20:46+00:00 17f930e0a649e158a567504df7bb01c90a8514c1 We can relocate @res_page assignment in find_in_block() to its caller, so unneeded parameter could be removed for cleanup. Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
We can relocate @res_page assignment in find_in_block() to
its caller, so unneeded parameter could be removed for cleanup.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
fscrypt: don't call no-key names "ciphertext names" 2020-09-24T04:29:49+00:00 Eric Biggers ebiggers@google.com 2020-09-24T04:26:23+00:00 70fb2612aab62d47e03f82eaa7384a8d30ca175d Currently we're using the term "ciphertext name" ambiguously because it can mean either the actual ciphertext filename, or the encoded filename that is shown when an encrypted directory is listed without its key. The latter we're now usually calling the "no-key name"; and while it's derived from the ciphertext name, it's not the same thing. To avoid this ambiguity, rename fscrypt_name::is_ciphertext_name to fscrypt_name::is_nokey_name, and update comments that say "ciphertext name" (or "encrypted name") to say "no-key name" instead when warranted. Link: https://lore.kernel.org/r/20200924042624.98439-2-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> 
Currently we're using the term "ciphertext name" ambiguously because it
can mean either the actual ciphertext filename, or the encoded filename
that is shown when an encrypted directory is listed without its key.
The latter we're now usually calling the "no-key name"; and while it's
derived from the ciphertext name, it's not the same thing.

To avoid this ambiguity, rename fscrypt_name::is_ciphertext_name to
fscrypt_name::is_nokey_name, and update comments that say "ciphertext
name" (or "encrypted name") to say "no-key name" instead when warranted.

Link: https://lore.kernel.org/r/20200924042624.98439-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
f2fs: use fscrypt_prepare_new_inode() and fscrypt_set_context() 2020-09-22T13:48:35+00:00 Eric Biggers ebiggers@google.com 2020-09-17T04:11:27+00:00 e075b6901047cd4c70b93cfcbe5f67dbc5741fb6 Convert f2fs to use the new functions fscrypt_prepare_new_inode() and fscrypt_set_context(). This avoids calling fscrypt_get_encryption_info() from under f2fs_lock_op(), which can deadlock because fscrypt_get_encryption_info() isn't GFP_NOFS-safe. For more details about this problem, see the earlier patch "fscrypt: add fscrypt_prepare_new_inode() and fscrypt_set_context()". This also fixes a f2fs-specific deadlock when the filesystem is mounted with '-o test_dummy_encryption' and a file is created in an unencrypted directory other than the root directory: INFO: task touch:207 blocked for more than 30 seconds. Not tainted 5.9.0-rc4-00099-g729e3d0919844 #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:touch state:D stack: 0 pid: 207 ppid: 167 flags:0x00000000 Call Trace: [...] lock_page include/linux/pagemap.h:548 [inline] pagecache_get_page+0x25e/0x310 mm/filemap.c:1682 find_or_create_page include/linux/pagemap.h:348 [inline] grab_cache_page include/linux/pagemap.h:424 [inline] f2fs_grab_cache_page fs/f2fs/f2fs.h:2395 [inline] f2fs_grab_cache_page fs/f2fs/f2fs.h:2373 [inline] __get_node_page.part.0+0x39/0x2d0 fs/f2fs/node.c:1350 __get_node_page fs/f2fs/node.c:35 [inline] f2fs_get_node_page+0x2e/0x60 fs/f2fs/node.c:1399 read_inline_xattr+0x88/0x140 fs/f2fs/xattr.c:288 lookup_all_xattrs+0x1f9/0x2c0 fs/f2fs/xattr.c:344 f2fs_getxattr+0x9b/0x160 fs/f2fs/xattr.c:532 f2fs_get_context+0x1e/0x20 fs/f2fs/super.c:2460 fscrypt_get_encryption_info+0x9b/0x450 fs/crypto/keysetup.c:472 fscrypt_inherit_context+0x2f/0xb0 fs/crypto/policy.c:640 f2fs_init_inode_metadata+0xab/0x340 fs/f2fs/dir.c:540 f2fs_add_inline_entry+0x145/0x390 fs/f2fs/inline.c:621 f2fs_add_dentry+0x31/0x80 fs/f2fs/dir.c:757 f2fs_do_add_link+0xcd/0x130 fs/f2fs/dir.c:798 f2fs_add_link fs/f2fs/f2fs.h:3234 [inline] f2fs_create+0x104/0x290 fs/f2fs/namei.c:344 lookup_open.isra.0+0x2de/0x500 fs/namei.c:3103 open_last_lookups+0xa9/0x340 fs/namei.c:3177 path_openat+0x8f/0x1b0 fs/namei.c:3365 do_filp_open+0x87/0x130 fs/namei.c:3395 do_sys_openat2+0x96/0x150 fs/open.c:1168 [...] That happened because f2fs_add_inline_entry() locks the directory inode's page in order to add the dentry, then f2fs_get_context() tries to lock it recursively in order to read the encryption xattr. This problem is specific to "test_dummy_encryption" because normally the directory's fscrypt_info would be set up prior to f2fs_add_inline_entry() in order to encrypt the new filename. Regardless, the new design fixes this test_dummy_encryption deadlock as well as potential deadlocks with fs reclaim, by setting up any needed fscrypt_info structs prior to taking so many locks. The test_dummy_encryption deadlock was reported by Daniel Rosenberg. Reported-by: Daniel Rosenberg <drosen@google.com> Acked-by: Jaegeuk Kim <jaegeuk@kernel.org> Link: https://lore.kernel.org/r/20200917041136.178600-5-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> 
Convert f2fs to use the new functions fscrypt_prepare_new_inode() and
fscrypt_set_context().  This avoids calling
fscrypt_get_encryption_info() from under f2fs_lock_op(), which can
deadlock because fscrypt_get_encryption_info() isn't GFP_NOFS-safe.

For more details about this problem, see the earlier patch
"fscrypt: add fscrypt_prepare_new_inode() and fscrypt_set_context()".

This also fixes a f2fs-specific deadlock when the filesystem is mounted
with '-o test_dummy_encryption' and a file is created in an unencrypted
directory other than the root directory:

    INFO: task touch:207 blocked for more than 30 seconds.
          Not tainted 5.9.0-rc4-00099-g729e3d0919844 #2
    "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    task:touch           state:D stack:    0 pid:  207 ppid:   167 flags:0x00000000
    Call Trace:
     [...]
     lock_page include/linux/pagemap.h:548 [inline]
     pagecache_get_page+0x25e/0x310 mm/filemap.c:1682
     find_or_create_page include/linux/pagemap.h:348 [inline]
     grab_cache_page include/linux/pagemap.h:424 [inline]
     f2fs_grab_cache_page fs/f2fs/f2fs.h:2395 [inline]
     f2fs_grab_cache_page fs/f2fs/f2fs.h:2373 [inline]
     __get_node_page.part.0+0x39/0x2d0 fs/f2fs/node.c:1350
     __get_node_page fs/f2fs/node.c:35 [inline]
     f2fs_get_node_page+0x2e/0x60 fs/f2fs/node.c:1399
     read_inline_xattr+0x88/0x140 fs/f2fs/xattr.c:288
     lookup_all_xattrs+0x1f9/0x2c0 fs/f2fs/xattr.c:344
     f2fs_getxattr+0x9b/0x160 fs/f2fs/xattr.c:532
     f2fs_get_context+0x1e/0x20 fs/f2fs/super.c:2460
     fscrypt_get_encryption_info+0x9b/0x450 fs/crypto/keysetup.c:472
     fscrypt_inherit_context+0x2f/0xb0 fs/crypto/policy.c:640
     f2fs_init_inode_metadata+0xab/0x340 fs/f2fs/dir.c:540
     f2fs_add_inline_entry+0x145/0x390 fs/f2fs/inline.c:621
     f2fs_add_dentry+0x31/0x80 fs/f2fs/dir.c:757
     f2fs_do_add_link+0xcd/0x130 fs/f2fs/dir.c:798
     f2fs_add_link fs/f2fs/f2fs.h:3234 [inline]
     f2fs_create+0x104/0x290 fs/f2fs/namei.c:344
     lookup_open.isra.0+0x2de/0x500 fs/namei.c:3103
     open_last_lookups+0xa9/0x340 fs/namei.c:3177
     path_openat+0x8f/0x1b0 fs/namei.c:3365
     do_filp_open+0x87/0x130 fs/namei.c:3395
     do_sys_openat2+0x96/0x150 fs/open.c:1168
     [...]

That happened because f2fs_add_inline_entry() locks the directory
inode's page in order to add the dentry, then f2fs_get_context() tries
to lock it recursively in order to read the encryption xattr.  This
problem is specific to "test_dummy_encryption" because normally the
directory's fscrypt_info would be set up prior to
f2fs_add_inline_entry() in order to encrypt the new filename.

Regardless, the new design fixes this test_dummy_encryption deadlock as
well as potential deadlocks with fs reclaim, by setting up any needed
fscrypt_info structs prior to taking so many locks.

The test_dummy_encryption deadlock was reported by Daniel Rosenberg.

Reported-by: Daniel Rosenberg <drosen@google.com>
Acked-by: Jaegeuk Kim <jaegeuk@kernel.org>
Link: https://lore.kernel.org/r/20200917041136.178600-5-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>