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2017-07-09Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4Linus Torvalds1-0/+3
Pull ext4 updates from Ted Ts'o: "The first major feature for ext4 this merge window is the largedir feature, which allows ext4 directories to support over 2 billion directory entries (assuming ~64 byte file names; in practice, users will run into practical performance limits first.) This feature was originally written by the Lustre team, and credit goes to Artem Blagodarenko from Seagate for getting this feature upstream. The second major major feature allows ext4 to support extended attribute values up to 64k. This feature was also originally from Lustre, and has been enhanced by Tahsin Erdogan from Google with a deduplication feature so that if multiple files have the same xattr value (for example, Windows ACL's stored by Samba), only one copy will be stored on disk for encoding and caching efficiency. We also have the usual set of bug fixes, cleanups, and optimizations" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (47 commits) ext4: fix spelling mistake: "prellocated" -> "preallocated" ext4: fix __ext4_new_inode() journal credits calculation ext4: skip ext4_init_security() and encryption on ea_inodes fs: generic_block_bmap(): initialize all of the fields in the temp bh ext4: change fast symlink test to not rely on i_blocks ext4: require key for truncate(2) of encrypted file ext4: don't bother checking for encryption key in ->mmap() ext4: check return value of kstrtoull correctly in reserved_clusters_store ext4: fix off-by-one fsmap error on 1k block filesystems ext4: return EFSBADCRC if a bad checksum error is found in ext4_find_entry() ext4: return EIO on read error in ext4_find_entry ext4: forbid encrypting root directory ext4: send parallel discards on commit completions ext4: avoid unnecessary stalls in ext4_evict_inode() ext4: add nombcache mount option ext4: strong binding of xattr inode references ext4: eliminate xattr entry e_hash recalculation for removes ext4: reserve space for xattr entries/names quota: add get_inode_usage callback to transfer multi-inode charges ext4: xattr inode deduplication ...
2017-07-06ext4: fix __ext4_new_inode() journal credits calculationTahsin Erdogan1-0/+3
ea_inode feature allows creating extended attributes that are up to 64k in size. Update __ext4_new_inode() to pick increased credit limits. To avoid overallocating too many journal credits, update __ext4_xattr_set_credits() to make a distinction between xattr create vs update. This helps __ext4_new_inode() because all attributes are known to be new, so we can save credits that are normally needed to delete old values. Also, have fscrypt specify its maximum context size so that we don't end up allocating credits for 64k size. Signed-off-by: Tahsin Erdogan <tahsin@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-23fscrypt: make ->dummy_context() return boolEric Biggers1-1/+1
This makes it consistent with ->is_encrypted(), ->empty_dir(), and fscrypt_dummy_context_enabled(). Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-06-23fscrypt: add support for AES-128-CBCDaniel Walter1-6/+10
fscrypt provides facilities to use different encryption algorithms which are selectable by userspace when setting the encryption policy. Currently, only AES-256-XTS for file contents and AES-256-CBC-CTS for file names are implemented. This is a clear case of kernel offers the mechanism and userspace selects a policy. Similar to what dm-crypt and ecryptfs have. This patch adds support for using AES-128-CBC for file contents and AES-128-CBC-CTS for file name encryption. To mitigate watermarking attacks, IVs are generated using the ESSIV algorithm. While AES-CBC is actually slightly less secure than AES-XTS from a security point of view, there is more widespread hardware support. Using AES-CBC gives us the acceptable performance while still providing a moderate level of security for persistent storage. Especially low-powered embedded devices with crypto accelerators such as CAAM or CESA often only support AES-CBC. Since using AES-CBC over AES-XTS is basically thought of a last resort, we use AES-128-CBC over AES-256-CBC since it has less encryption rounds and yields noticeable better performance starting from a file size of just a few kB. Signed-off-by: Daniel Walter <dwalter@sigma-star.at> [david@sigma-star.at: addressed review comments] Signed-off-by: David Gstir <david@sigma-star.at> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-04-30fscrypt: remove fscrypt_symlink_data_len()Eric Biggers1-11/+0
fscrypt_symlink_data_len() is never called and can be removed. Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Richard Weinberger <richard@nod.at> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-03-15fscrypt: eliminate ->prepare_context() operationEric Biggers1-1/+0
The only use of the ->prepare_context() fscrypt operation was to allow ext4 to evict inline data from the inode before ->set_context(). However, there is no reason why this cannot be done as simply the first step in ->set_context(), and in fact it makes more sense to do it that way because then the policy modes and flags get validated before any real work is done. Therefore, merge ext4_prepare_context() into ext4_set_context(), and remove ->prepare_context(). Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-02-06fscrypt: split supp and notsupp declarations into their own headersEric Biggers1-0/+146
Previously, each filesystem configured without encryption support would define all the public fscrypt functions to their notsupp_* stubs. This list of #defines had to be updated in every filesystem whenever a change was made to the public fscrypt functions. To make things more maintainable now that we have three filesystems using fscrypt, split the old header fscrypto.h into several new headers. fscrypt_supp.h contains the real declarations and is included by filesystems when configured with encryption support, whereas fscrypt_notsupp.h contains the inline stubs and is included by filesystems when configured without encryption support. fscrypt_common.h contains common declarations needed by both. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>