linux.git/fs/f2fs/dir.c, branch v5.9

f2fs: fix typo in comment of f2fs_do_add_link

2020-07-08T04:51:45+00:00

stakable/stackable

Signed-off-by: Liu Song 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: avoid utf8_strncasecmp() with unstable name

2020-06-09T03:37:53+00:00

If the dentry name passed to ->d_compare() fits in dentry::d_iname, then
it may be concurrently modified by a rename.  This can cause undefined
behavior (possibly out-of-bounds memory accesses or crashes) in
utf8_strncasecmp(), since fs/unicode/ isn't written to handle strings
that may be concurrently modified.

Fix this by first copying the filename to a stack buffer if needed.
This way we get a stable snapshot of the filename.

Fixes: 2c2eb7a300cd ("f2fs: Support case-insensitive file name lookups")
Cc:  # v5.4+
Cc: Al Viro 
Cc: Daniel Rosenberg 
Cc: Gabriel Krisman Bertazi 
Signed-off-by: Eric Biggers 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: rework filename handling

2020-05-12T03:36:46+00:00

Rework f2fs's handling of filenames to use a new 'struct f2fs_filename'.
Similar to 'struct ext4_filename', this stores the usr_fname, disk_name,
dirhash, crypto_buf, and casefolded name.  Some of these names can be
NULL in some cases.  'struct f2fs_filename' differs from
'struct fscrypt_name' mainly in that the casefolded name is included.

For user-initiated directory operations like lookup() and create(),
initialize the f2fs_filename by translating the corresponding
fscrypt_name, then computing the dirhash and casefolded name if needed.

This makes the dirhash and casefolded name be cached for each syscall,
so we don't have to recompute them repeatedly.  (Previously, f2fs
computed the dirhash once per directory level, and the casefolded name
once per directory block.)  This improves performance.

This rework also makes it much easier to correctly handle all
combinations of normal, encrypted, casefolded, and encrypted+casefolded
directories.  (The fourth isn't supported yet but is being worked on.)

The only other cases where an f2fs_filename gets initialized are for two
filesystem-internal operations: (1) when converting an inline directory
to a regular one, we grab the needed disk_name and hash from an existing
f2fs_dir_entry; and (2) when roll-forward recovering a new dentry, we
grab the needed disk_name from f2fs_inode::i_name and compute the hash.

Signed-off-by: Eric Biggers 
Signed-off-by: Jaegeuk Kim

f2fs: split f2fs_d_compare() from f2fs_match_name()

2020-05-12T03:36:46+00:00

Sharing f2fs_ci_compare() between comparing cached dentries
(f2fs_d_compare()) and comparing on-disk dentries (f2fs_match_name())
doesn't work as well as intended, as these actions fundamentally differ
in several ways (e.g. whether the task may sleep, whether the directory
is stable, whether the casefolded name was precomputed, whether the
dentry will need to be decrypted once we allow casefold+encrypt, etc.)

Just make f2fs_d_compare() implement what it needs directly, and rework
f2fs_ci_compare() to be specialized for f2fs_match_name().

Signed-off-by: Eric Biggers 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: clean up f2fs_may_encrypt()

2020-03-31T03:46:24+00:00

Merge below two conditions into f2fs_may_encrypt() for cleanup
- IS_ENCRYPTED()
- DUMMY_ENCRYPTION_ENABLED()

Check IS_ENCRYPTED(inode) condition in f2fs_init_inode_metadata()
is enough since we have already set encrypt flag in f2fs_new_inode().

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

f2fs: don't change inode status under page lock

2020-03-31T03:46:23+00:00

In order to shrink page lock coverage.

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

Merge tag 'f2fs-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

2020-01-30T23:39:24+00:00

Pull f2fs updates from Jaegeuk Kim:
 "In this series, we've implemented transparent compression
  experimentally. It supports LZO and LZ4, but will add more later as we
  investigate in the field more.

  At this point, the feature doesn't expose compressed space to user
  directly in order to guarantee potential data updates later to the
  space. Instead, the main goal is to reduce data writes to flash disk
  as much as possible, resulting in extending disk life time as well as
  relaxing IO congestion.

  Alternatively, we're also considering to add ioctl() to reclaim
  compressed space and show it to user after putting the immutable bit.

  Enhancements:
   - add compression support
   - avoid unnecessary locks in quota ops
   - harden power-cut scenario for zoned block devices
   - use private bio_set to avoid IO congestion
   - replace GC mutex with rwsem to serialize callers

  Bug fixes:
   - fix dentry consistency and memory corruption in rename()'s error case
   - fix wrong swap extent reports
   - fix casefolding bugs
   - change lock coverage to avoid deadlock
   - avoid GFP_KERNEL under f2fs_lock_op

  And, we've cleaned up sysfs entries to prepare no debugfs"

* tag 'f2fs-for-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (31 commits)
  f2fs: fix race conditions in ->d_compare() and ->d_hash()
  f2fs: fix dcache lookup of !casefolded directories
  f2fs: Add f2fs stats to sysfs
  f2fs: delete duplicate information on sysfs nodes
  f2fs: change to use rwsem for gc_mutex
  f2fs: update f2fs document regarding to fsync_mode
  f2fs: add a way to turn off ipu bio cache
  f2fs: code cleanup for f2fs_statfs_project()
  f2fs: fix miscounted block limit in f2fs_statfs_project()
  f2fs: show the CP_PAUSE reason in checkpoint traces
  f2fs: fix deadlock allocating bio_post_read_ctx from mempool
  f2fs: remove unneeded check for error allocating bio_post_read_ctx
  f2fs: convert inline_dir early before starting rename
  f2fs: fix memleak of kobject
  f2fs: fix to add swap extent correctly
  f2fs: run fsck when getting bad inode during GC
  f2fs: support data compression
  f2fs: free sysfs kobject
  f2fs: declare nested quota_sem and remove unnecessary sems
  f2fs: don't put new_page twice in f2fs_rename
  ...

f2fs: fix race conditions in ->d_compare() and ->d_hash()

2020-01-24T18:04:09+00:00

Since ->d_compare() and ->d_hash() can be called in RCU-walk mode,
->d_parent and ->d_inode can be concurrently modified, and in
particular, ->d_inode may be changed to NULL.  For f2fs_d_hash() this
resulted in a reproducible NULL dereference if a lookup is done in a
directory being deleted, e.g. with:

	int main()
	{
		if (fork()) {
			for (;;) {
				mkdir("subdir", 0700);
				rmdir("subdir");
			}
		} else {
			for (;;)
				access("subdir/file", 0);
		}
	}

... or by running the 't_encrypted_d_revalidate' program from xfstests.
Both repros work in any directory on a filesystem with the encoding
feature, even if the directory doesn't actually have the casefold flag.

I couldn't reproduce a crash in f2fs_d_compare(), but it appears that a
similar crash is possible there.

Fix these bugs by reading ->d_parent and ->d_inode using READ_ONCE() and
falling back to the case sensitive behavior if the inode is NULL.

Reported-by: Al Viro 
Fixes: 2c2eb7a300cd ("f2fs: Support case-insensitive file name lookups")
Cc:  # v5.4+
Signed-off-by: Eric Biggers 
Signed-off-by: Jaegeuk Kim

f2fs: fix dcache lookup of !casefolded directories

2020-01-24T17:53:02+00:00

Do the name comparison for non-casefolded directories correctly.

This is analogous to ext4's commit 66883da1eee8 ("ext4: fix dcache
lookup of !casefolded directories").

Fixes: 2c2eb7a300cd ("f2fs: Support case-insensitive file name lookups")
Cc:  # v5.4+
Signed-off-by: Eric Biggers 
Signed-off-by: Jaegeuk Kim

f2fs: convert inline_dir early before starting rename

2020-01-18T00:48:42+00:00

If we hit an error during rename, we'll get two dentries in different
directories.

Chao adds to check the room in inline_dir which can avoid needless
inversion. This should be done by inode_lock(&old_dir).

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