linux.git/fs/f2fs/dir.c, branch v5.5

f2fs: show f2fs instance in printk_ratelimited

2019-11-19T22:41:21+00:00

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 
Signed-off-by: Jaegeuk Kim

f2fs: fix to avoid accessing uninitialized field of inode page in is_alive()

2019-09-16T15:38:26+00:00

If inode is newly created, inode page may not synchronize with inode cache,
so fields like .i_inline or .i_extra_isize could be wrong, in below call
path, we may access such wrong fields, result in failing to migrate valid
target block.

Thread A				Thread B
- f2fs_create
 - f2fs_add_link
  - f2fs_add_dentry
   - f2fs_init_inode_metadata
    - f2fs_add_inline_entry
     - f2fs_new_inode_page
     - f2fs_put_page
     : inode page wasn't updated with inode cache
					- gc_data_segment
					 - is_alive
					  - f2fs_get_node_page
					  - datablock_addr
					   - offset_in_addr
					   : access uninitialized fields

Fixes: 7a2af766af15 ("f2fs: enhance on-disk inode structure scalability")
Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: optimize case-insensitive lookups

2019-09-06T23:18:12+00:00

This patch ports below casefold enhancement patch from ext4 to f2fs

commit 3ae72562ad91 ("ext4: optimize case-insensitive lookups")

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: introduce f2fs_match_name() for cleanup

2019-08-23T14:57:15+00:00

This patch introduces f2fs_match_name() for cleanup.

BTW, it avoids to fallback to normal comparison once it doesn't
match casefolded name.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: Support case-insensitive file name lookups

2019-08-23T14:57:13+00:00

Modeled after commit b886ee3e778e ("ext4: Support case-insensitive file
name lookups")

"""
This patch implements the actual support for case-insensitive file name
lookups in f2fs, based on the feature bit and the encoding stored in the
superblock.

A filesystem that has the casefold feature set is able to configure
directories with the +F (F2FS_CASEFOLD_FL) attribute, enabling lookups
to succeed in that directory in a case-insensitive fashion, i.e: match
a directory entry even if the name used by userspace is not a byte per
byte match with the disk name, but is an equivalent case-insensitive
version of the Unicode string.  This operation is called a
case-insensitive file name lookup.

The feature is configured as an inode attribute applied to directories
and inherited by its children.  This attribute can only be enabled on
empty directories for filesystems that support the encoding feature,
thus preventing collision of file names that only differ by case.

* dcache handling:

For a +F directory, F2Fs only stores the first equivalent name dentry
used in the dcache. This is done to prevent unintentional duplication of
dentries in the dcache, while also allowing the VFS code to quickly find
the right entry in the cache despite which equivalent string was used in
a previous lookup, without having to resort to ->lookup().

d_hash() of casefolded directories is implemented as the hash of the
casefolded string, such that we always have a well-known bucket for all
the equivalencies of the same string. d_compare() uses the
utf8_strncasecmp() infrastructure, which handles the comparison of
equivalent, same case, names as well.

For now, negative lookups are not inserted in the dcache, since they
would need to be invalidated anyway, because we can't trust missing file
dentries.  This is bad for performance but requires some leveraging of
the vfs layer to fix.  We can live without that for now, and so does
everyone else.

* on-disk data:

Despite using a specific version of the name as the internal
representation within the dcache, the name stored and fetched from the
disk is a byte-per-byte match with what the user requested, making this
implementation 'name-preserving'. i.e. no actual information is lost
when writing to storage.

DX is supported by modifying the hashes used in +F directories to make
them case/encoding-aware.  The new disk hashes are calculated as the
hash of the full casefolded string, instead of the string directly.
This allows us to efficiently search for file names in the htree without
requiring the user to provide an exact name.

* Dealing with invalid sequences:

By default, when a invalid UTF-8 sequence is identified, ext4 will treat
it as an opaque byte sequence, ignoring the encoding and reverting to
the old behavior for that unique file.  This means that case-insensitive
file name lookup will not work only for that file.  An optional bit can
be set in the superblock telling the filesystem code and userspace tools
to enforce the encoding.  When that optional bit is set, any attempt to
create a file name using an invalid UTF-8 sequence will fail and return
an error to userspace.

* Normalization algorithm:

The UTF-8 algorithms used to compare strings in f2fs is implemented
in fs/unicode, and is based on a previous version developed by
SGI.  It implements the Canonical decomposition (NFD) algorithm
described by the Unicode specification 12.1, or higher, combined with
the elimination of ignorable code points (NFDi) and full
case-folding (CF) as documented in fs/unicode/utf8_norm.c.

NFD seems to be the best normalization method for F2FS because:

  - It has a lower cost than NFC/NFKC (which requires
    decomposing to NFD as an intermediary step)
  - It doesn't eliminate important semantic meaning like
    compatibility decompositions.

Although:

- This implementation is not completely linguistic accurate, because
different languages have conflicting rules, which would require the
specialization of the filesystem to a given locale, which brings all
sorts of problems for removable media and for users who use more than
one language.
"""

Signed-off-by: Daniel Rosenberg 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: use generic EFSBADCRC/EFSCORRUPTED

2019-07-02T22:40:41+00:00

f2fs uses EFAULT as error number to indicate filesystem is corrupted
all the time, but generic filesystems use EUCLEAN for such condition,
we need to change to follow others.

This patch adds two new macros as below to wrap more generic error
code macros, and spread them in code.

EFSBADCRC	EBADMSG		/* Bad CRC detected */
EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */

Reported-by: Pavel Machek 
Signed-off-by: Chao Yu 
Acked-by: Pavel Machek 
Signed-off-by: Jaegeuk Kim

f2fs: introduce f2fs_ macros to wrap f2fs_printk()

2019-07-02T22:40:40+00:00

- Add and use f2fs_ macros
- Convert f2fs_msg to f2fs_printk
- Remove level from f2fs_printk and embed the level in the format
- Coalesce formats and align multi-line arguments
- Remove unnecessary duplicate extern f2fs_msg f2fs.h

Signed-off-by: Joe Perches 
Signed-off-by: Chao Yu 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: fix sparse warning

2019-05-30T16:48:45+00:00

make C=2 CHECKFLAGS="-D__CHECK_ENDIAN__"

CHECK   dir.c
dir.c:842:50: warning: cast from restricted __le32
CHECK   node.c
node.c:2759:40: warning: restricted __le32 degrades to integer

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

Merge tag 'f2fs-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

2019-03-15T20:42:53+00:00

Pull f2fs updates from Jaegeuk Kim:
 "We've continued mainly to fix bugs in this round, as f2fs has been
  shipped in more devices. Especially, we've focused on stabilizing
  checkpoint=disable feature, and provided some interfaces for QA.

  Enhancements:
   - expose FS_NOCOW_FL for pin_file
   - run discard jobs at unmount time with timeout
   - tune discarding thread to avoid idling which consumes power
   - some checking codes to address vulnerabilities
   - give random value to i_generation
   - shutdown with more flags for QA

  Bug fixes:
   - clean up stale objects when mount is failed along with
     checkpoint=disable
   - fix system being stuck due to wrong count by atomic writes
   - handle some corrupted disk cases
   - fix a deadlock in f2fs_read_inline_dir

  We've also added some minor build error fixes and clean-up patches"

* tag 'f2fs-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (53 commits)
  f2fs: set pin_file under CAP_SYS_ADMIN
  f2fs: fix to avoid deadlock in f2fs_read_inline_dir()
  f2fs: fix to adapt small inline xattr space in __find_inline_xattr()
  f2fs: fix to do sanity check with inode.i_inline_xattr_size
  f2fs: give some messages for inline_xattr_size
  f2fs: don't trigger read IO for beyond EOF page
  f2fs: fix to add refcount once page is tagged PG_private
  f2fs: remove wrong comment in f2fs_invalidate_page()
  f2fs: fix to use kvfree instead of kzfree
  f2fs: print more parameters in trace_f2fs_map_blocks
  f2fs: trace f2fs_ioc_shutdown
  f2fs: fix to avoid deadlock of atomic file operations
  f2fs: fix to dirty inode for i_mode recovery
  f2fs: give random value to i_generation
  f2fs: no need to take page lock in readdir
  f2fs: fix to update iostat correctly in IPU path
  f2fs: fix encrypted page memory leak
  f2fs: make fault injection covering __submit_flush_wait()
  f2fs: fix to retry fill_super only if recovery failed
  f2fs: silence VM_WARN_ON_ONCE in mempool_alloc
  ...

f2fs: fix to add refcount once page is tagged PG_private

2019-03-13T01:59:19+00:00

As Gao Xiang reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=202749

f2fs may skip pageout() due to incorrect page reference count.

The problem here is that MM defined the rule [1] very clearly that
once page was set with PG_private flag, we should increment the
refcount in that page, also main flows like pageout(), migrate_page()
will assume there is one additional page reference count if
page_has_private() returns true.

But currently, f2fs won't add/del refcount when changing PG_private
flag. Anyway, f2fs should follow MM's rule to make MM's related flows
running as expected.

[1] https://lore.kernel.org/lkml/2b19b3c4-2bc4-15fa-15cc-27a13e5c7af1@aol.com/

Reported-by: Gao Xiang 
Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim