Pull ecryptfs updates from Tyler Hicks:
 "No functional changes, just code cleanups:

   - replace kmalloc()/snprintf() with kasprintf()

   - simplify code flow by removing an unnecessary variable"

* tag 'ecryptfs-7.2-rc1-updates' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
  ecryptfs: use kasprintf in ecryptfs_crypto_api_algify_cipher_name
  ecryptfs: remove redundant variable found_auth_tok

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Use kasprintf() to simplify ecryptfs_crypto_api_algify_cipher_name().

Use const char * for the read-only cipher name and chaining modifier
while at it.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Tyler Hicks <code@tyhicks.com>

The found_auth_tok variable is no longer needed, as the fact of finding
a token is determined directly by jumping to the found_matching_auth_tok
label inside the loop.

Remove found_auth_tok, simplifying the function logic.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Alexey Velichayshiy <a.velichayshiy@ispras.ru>
[tyhicks: Unsplit log message string]
Signed-off-by: Tyler Hicks <code@tyhicks.com>

Pull eCryptfs updates from Tyler Hicks:

 - avoid unnecessary eCryptfs inode timestamp truncation by re-using the
   lower filesystem's time granularity

 - various small code cleanups

 - reorganize the setattr hook inode resizing to improve style and
   readability, remove an unnecessary memory allocation when shrinking,
   and to support an upcoming rework of the VFS interfaces involved in
   truncation

* tag 'ecryptfs-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
  ecryptfs: keep the lower iattr contained in truncate_upper
  ecryptfs: factor out a ecryptfs_iattr_to_lower helper
  ecryptfs: merge ecryptfs_inode_newsize_ok into truncate_upper
  ecryptfs: combine the two ATTR_SIZE blocks in ecryptfs_setattr
  ecryptfs: use ZERO_PAGE instead of allocating zeroed memory in truncate_upper
  ecryptfs: streamline truncate_upper
  ecryptfs: cleanup ecryptfs_setattr
  ecryptfs: Drop TODO comment in ecryptfs_derive_iv
  ecryptfs: Fix typo in ecryptfs_derive_iv function comment
  ecryptfs: Log function name only once in decode_and_decrypt_filename
  ecryptfs: Remove redundant if checks in encrypt_and_encode_filename
  ecryptfs: Fix tag number in encrypt_filename() error message
  ecryptfs: Use struct_size to improve process_response + send_miscdev
  ecryptfs: Replace memcpy + manual NUL termination with strscpy
  ecryptfs: Set s_time_gran to get correct time granularity

Currently the two callers of truncate_upper handle passing information
very differently.  ecryptfs_truncate passes a zeroed lower_ia and expects
truncate_upper to fill it in from the upper ia created just for that,
while ecryptfs_setattr passes a fully initialized lower_ia copied from
the upper one.  Both of them then call notify_change on the lower_ia.

Switch to only passing the upper ia, and derive the lower ia from it
inside truncate_upper, and call notify_change inside the function itself.
Because the old name is misleading now, rename the resulting function to
__ecryptfs_truncate as it deals with both the lower and upper inodes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tyler Hicks <code@tyhicks.com>

Prepare for using the code to create a lower struct iattr in multiple
places.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tyler Hicks <code@tyhicks.com>

Both callers of ecryptfs_inode_newsize_ok call truncate_upper right
after.  Merge ecryptfs_inode_newsize_ok into truncate_upper to simplify
the logic.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tyler Hicks <code@tyhicks.com>

Simplify the logic in ecryptfs_setattr by combining the two ATTR_SIZE
blocks.  This initializes lower_ia before the size check, which is
obviously correct as the size check doesn't look at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tyler Hicks <code@tyhicks.com>

Use the existing pre-zeroed memory instead of allocating a new chunk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tyler Hicks <code@tyhicks.com>