BMC/Intel-BMC/linux.git/fs/ext4/symlink.c, branch dev

Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2015-06-25T21:06:55+00:00

Pull ext4 updates from Ted Ts'o: "A very large number of cleanups and bug fixes --- in particular for the ext4 encryption patches, which is a new feature added in the last merge window. Also fix a number of long-standing xfstest failures. (Quota writes failing due to ENOSPC, a race between truncate and writepage in data=journalled mode that was causing generic/068 to fail, and other corner cases.) Also add support for FALLOC_FL_INSERT_RANGE, and improve jbd2 performance eliminating locking when a buffer is modified more than once during a transaction (which is very common for allocation bitmaps, for example), in which case the state of the journalled buffer head doesn't need to change" [ I renamed "ext4_follow_link()" to "ext4_encrypted_follow_link()" in the merge resolution, to make it clear that that function is _only_ used for encrypted symlinks. The function doesn't actually work for non-encrypted symlinks at all, and they use the generic helpers - Linus ] * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (52 commits) ext4: set lazytime on remount if MS_LAZYTIME is set by mount ext4: only call ext4_truncate when size <= isize ext4: make online defrag error reporting consistent ext4: minor cleanup of ext4_da_reserve_space() ext4: don't retry file block mapping on bigalloc fs with non-extent file ext4: prevent ext4_quota_write() from failing due to ENOSPC ext4: call sync_blockdev() before invalidate_bdev() in put_super() jbd2: speedup jbd2_journal_dirty_metadata() jbd2: get rid of open coded allocation retry loop ext4: improve warning directory handling messages jbd2: fix ocfs2 corrupt when updating journal superblock fails ext4: mballoc: avoid 20-argument function call ext4: wait for existing dio workers in ext4_alloc_file_blocks() ext4: recalculate journal credits as inode depth changes jbd2: use GFP_NOFS in jbd2_cleanup_journal_tail() ext4: use swap() in mext_page_double_lock() ext4: use swap() in memswap() ext4: fix race between truncate and __ext4_journalled_writepage() ext4 crypto: fail the mount if blocksize != pagesize ext4: Add support FALLOC_FL_INSERT_RANGE for fallocate ...

ext4 crypto: use per-inode tfm structure

2015-05-31T17:34:22+00:00

As suggested by Herbert Xu, we shouldn't allocate a new tfm each time we read or write a page. Instead we can use a single tfm hanging off the inode's crypt_info structure for all of our encryption needs for that inode, since the tfm can be used by multiple crypto requests in parallel. Also use cmpxchg() to avoid races that could result in crypt_info structure getting doubly allocated or doubly freed. Signed-off-by: Theodore Ts'o

ext4 crypto: reorganize how we store keys in the inode

2015-05-18T17:17:47+00:00

This is a pretty massive patch which does a number of different things: 1) The per-inode encryption information is now stored in an allocated data structure, ext4_crypt_info, instead of directly in the node. This reduces the size usage of an in-memory inode when it is not using encryption. 2) We drop the ext4_fname_crypto_ctx entirely, and use the per-inode encryption structure instead. This remove an unnecessary memory allocation and free for the fname_crypto_ctx as well as allowing us to reuse the ctfm in a directory for multiple lookups and file creations. 3) We also cache the inode's policy information in the ext4_crypt_info structure so we don't have to continually read it out of the extended attributes. 4) We now keep the keyring key in the inode's encryption structure instead of releasing it after we are done using it to derive the per-inode key. This allows us to test to see if the key has been revoked; if it has, we prevent the use of the derived key and free it. 5) When an inode is released (or when the derived key is freed), we will use memset_explicit() to zero out the derived key, so it's not left hanging around in memory. This implies that when a user logs out, it is important to first revoke the key, and then unlink it, and then finally, to use "echo 3 > /proc/sys/vm/drop_caches" to release any decrypted pages and dcache entries from the system caches. 6) All this, and we also shrink the number of lines of code by around 100. :-) Signed-off-by: Theodore Ts'o

ext4 crypto: don't allocate a page when encrypting/decrypting file names

2015-05-18T17:15:47+00:00

Signed-off-by: Theodore Ts'o

don't pass nameidata to ->follow_link()

2015-05-11T02:20:15+00:00

its only use is getting passed to nd_jump_link(), which can obtain it from current->nameidata Signed-off-by: Al Viro

new ->follow_link() and ->put_link() calling conventions

2015-05-11T02:19:45+00:00

a) instead of storing the symlink body (via nd_set_link()) and returning an opaque pointer later passed to ->put_link(), ->follow_link() _stores_ that opaque pointer (into void * passed by address by caller) and returns the symlink body. Returning ERR_PTR() on error, NULL on jump (procfs magic symlinks) and pointer to symlink body for normal symlinks. Stored pointer is ignored in all cases except the last one. Storing NULL for opaque pointer (or not storing it at all) means no call of ->put_link(). b) the body used to be passed to ->put_link() implicitly (via nameidata). Now only the opaque pointer is. In the cases when we used the symlink body to free stuff, ->follow_link() now should store it as opaque pointer in addition to returning it. Signed-off-by: Al Viro

ext4: switch to simple_follow_link()

2015-05-11T02:18:23+00:00

for fast symlinks only, of course... Reviewed-by: Jan Kara Signed-off-by: Al Viro

ext4: split inode_operations for encrypted symlinks off the rest

2015-05-11T02:18:20+00:00

Signed-off-by: Al Viro

Merge tag 'for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2015-05-04T01:23:53+00:00

Pull ext4 fixes from Ted Ts'o: "Some miscellaneous bug fixes and some final on-disk and ABI changes for ext4 encryption which provide better security and performance" * tag 'for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix growing of tiny filesystems ext4: move check under lock scope to close a race. ext4: fix data corruption caused by unwritten and delayed extents ext4 crypto: remove duplicated encryption mode definitions ext4 crypto: do not select from EXT4_FS_ENCRYPTION ext4 crypto: add padding to filenames before encrypting ext4 crypto: simplify and speed up filename encryption

ext4 crypto: simplify and speed up filename encryption

2015-05-01T20:56:45+00:00

Avoid using SHA-1 when calculating the user-visible filename when the encryption key is available, and avoid decrypting lots of filenames when searching for a directory entry in a directory block. Change-Id: If4655f144784978ba0305b597bfa1c8d7bb69e63 Signed-off-by: Theodore Ts'o