Commit Graph

8 Commits

Author SHA1 Message Date
Matthew Wilcox (Oracle)
73bb49da50 mm/readahead: make page_cache_ra_unbounded take a readahead_control
Define it in the callers instead of in page_cache_ra_unbounded().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Link: https://lkml.kernel.org/r/20200903140844.14194-4-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16 11:11:16 -07:00
Linus Torvalds
3be20b6fc1 This is the second round of ext4 commits for 5.8 merge window. It
includes the per-inode DAX support, which was dependant on the DAX
 infrastructure which came in via the XFS tree, and a number of
 regression and bug fixes; most notably the "BUG: using
 smp_processor_id() in preemptible code in ext4_mb_new_blocks" reported
 by syzkaller.
 -----BEGIN PGP SIGNATURE-----
 
 iQEzBAABCAAdFiEEK2m5VNv+CHkogTfJ8vlZVpUNgaMFAl7mgCcACgkQ8vlZVpUN
 gaPftwf8C4w/7SG+CYLdwg0d2u9TKk77yDuWaioFHOcMSjZvG4TCSgtMhZxQnyty
 9t4yqacILx12pCj/mZnrZp5BOSn9O2ZbuDoXNKNrFXU0BF+CsbnhvJvrrh1j/MUa
 PPtcqyGFdOLSDvHSD9xPVT76juwh79aR8vB7qnQXaEO5wcLodZWoqBEFSKCl6Bo8
 hjXs1EXidusKsoarQxW6mEITmnhU2S2fuCVDgVcoM/LmKwzbgqvlWrentq9u8qLH
 W+XbjWgUtCM1byeDZWqe5FYyyJ8x+dTv7H5an3KR92EN6hKo5AOvzA0I41pZscq/
 bJ9p2THDxJQX4rJBevGAS5mZ6hTkRw==
 =z6eO
 -----END PGP SIGNATURE-----

Merge tag 'ext4-for-linus-5.8-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull more ext4 updates from Ted Ts'o:
 "This is the second round of ext4 commits for 5.8 merge window [1].

  It includes the per-inode DAX support, which was dependant on the DAX
  infrastructure which came in via the XFS tree, and a number of
  regression and bug fixes; most notably the "BUG: using
  smp_processor_id() in preemptible code in ext4_mb_new_blocks" reported
  by syzkaller"

[1] The pull request actually came in 15 minutes after I had tagged the
    rc1 release. Tssk, tssk, late..   - Linus

* tag 'ext4-for-linus-5.8-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4, jbd2: ensure panic by fix a race between jbd2 abort and ext4 error handlers
  ext4: support xattr gnu.* namespace for the Hurd
  ext4: mballoc: Use this_cpu_read instead of this_cpu_ptr
  ext4: avoid utf8_strncasecmp() with unstable name
  ext4: stop overwrite the errcode in ext4_setup_super
  ext4: fix partial cluster initialization when splitting extent
  ext4: avoid race conditions when remounting with options that change dax
  Documentation/dax: Update DAX enablement for ext4
  fs/ext4: Introduce DAX inode flag
  fs/ext4: Remove jflag variable
  fs/ext4: Make DAX mount option a tri-state
  fs/ext4: Only change S_DAX on inode load
  fs/ext4: Update ext4_should_use_dax()
  fs/ext4: Change EXT4_MOUNT_DAX to EXT4_MOUNT_DAX_ALWAYS
  fs/ext4: Disallow verity if inode is DAX
  fs/ext4: Narrow scope of DAX check in setflags
2020-06-15 09:32:10 -07:00
Matthew Wilcox (Oracle)
2c684234d3 mm: add page_cache_readahead_unbounded
ext4 and f2fs have duplicated the guts of the readahead code so they can
read past i_size.  Instead, separate out the guts of the readahead code
so they can call it directly.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-14-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 10:59:06 -07:00
Ira Weiny
b383a73f2b fs/ext4: Introduce DAX inode flag
Add a flag ([EXT4|FS]_DAX_FL) to preserve FS_XFLAG_DAX in the ext4
inode.

Set the flag to be user visible and changeable.  Set the flag to be
inherited.  Allow applications to change the flag at any time except if
it conflicts with the set of mutually exclusive flags (Currently VERITY,
ENCRYPT, JOURNAL_DATA).

Furthermore, restrict setting any of the exclusive flags if DAX is set.

While conceptually possible, we do not allow setting EXT4_DAX_FL while
at the same time clearing exclusion flags (or vice versa) for 2 reasons:

	1) The DAX flag does not take effect immediately which
	   introduces quite a bit of complexity
	2) There is no clear use case for being this flexible

Finally, on regular files, flag the inode to not be cached to facilitate
changing S_DAX on the next creation of the inode.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>

Link: https://lore.kernel.org/r/20200528150003.828793-9-ira.weiny@intel.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-05-28 22:09:47 -04:00
Ira Weiny
043546e46d fs/ext4: Only change S_DAX on inode load
To prevent complications with in memory inodes we only set S_DAX on
inode load.  FS_XFLAG_DAX can be changed at any time and S_DAX will
change after inode eviction and reload.

Add init bool to ext4_set_inode_flags() to indicate if the inode is
being newly initialized.

Assert that S_DAX is not set on an inode which is just being loaded.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

Link: https://lore.kernel.org/r/20200528150003.828793-6-ira.weiny@intel.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-05-28 22:09:47 -04:00
Ira Weiny
6c0d077ff8 fs/ext4: Disallow verity if inode is DAX
Verity and DAX are incompatible.  Changing the DAX mode due to a verity
flag change is wrong without a corresponding address_space_operations
update.

Make the 2 options mutually exclusive by returning an error if DAX was
set first.

(Setting DAX is already disabled if Verity is set first.)

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

Link: https://lore.kernel.org/r/20200528150003.828793-3-ira.weiny@intel.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2020-05-28 22:09:47 -04:00
Eric Biggers
fd39073dba fs-verity: implement readahead of Merkle tree pages
When fs-verity verifies data pages, currently it reads each Merkle tree
page synchronously using read_mapping_page().

Therefore, when the Merkle tree pages aren't already cached, fs-verity
causes an extra 4 KiB I/O request for every 512 KiB of data (assuming
that the Merkle tree uses SHA-256 and 4 KiB blocks).  This results in
more I/O requests and performance loss than is strictly necessary.

Therefore, implement readahead of the Merkle tree pages.

For simplicity, we take advantage of the fact that the kernel already
does readahead of the file's *data*, just like it does for any other
file.  Due to this, we don't really need a separate readahead state
(struct file_ra_state) just for the Merkle tree, but rather we just need
to piggy-back on the existing data readahead requests.

We also only really need to bother with the first level of the Merkle
tree, since the usual fan-out factor is 128, so normally over 99% of
Merkle tree I/O requests are for the first level.

Therefore, make fsverity_verify_bio() enable readahead of the first
Merkle tree level, for up to 1/4 the number of pages in the bio, when it
sees that the REQ_RAHEAD flag is set on the bio.  The readahead size is
then passed down to ->read_merkle_tree_page() for the filesystem to
(optionally) implement if it sees that the requested page is uncached.

While we're at it, also make build_merkle_tree_level() set the Merkle
tree readahead size, since it's easy to do there.

However, for now don't set the readahead size in fsverity_verify_page(),
since currently it's only used to verify holes on ext4 and f2fs, and it
would need parameters added to know how much to read ahead.

This patch significantly improves fs-verity sequential read performance.
Some quick benchmarks with 'cat'-ing a 250MB file after dropping caches:

    On an ARM64 phone (using sha256-ce):
        Before: 217 MB/s
        After: 263 MB/s
        (compare to sha256sum of non-verity file: 357 MB/s)

    In an x86_64 VM (using sha256-avx2):
        Before: 173 MB/s
        After: 215 MB/s
        (compare to sha256sum of non-verity file: 223 MB/s)

Link: https://lore.kernel.org/r/20200106205533.137005-1-ebiggers@kernel.org
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-01-14 13:27:32 -08:00
Eric Biggers
c93d8f8858 ext4: add basic fs-verity support
Add most of fs-verity support to ext4.  fs-verity is a filesystem
feature that enables transparent integrity protection and authentication
of read-only files.  It uses a dm-verity like mechanism at the file
level: a Merkle tree is used to verify any block in the file in
log(filesize) time.  It is implemented mainly by helper functions in
fs/verity/.  See Documentation/filesystems/fsverity.rst for the full
documentation.

This commit adds all of ext4 fs-verity support except for the actual
data verification, including:

- Adding a filesystem feature flag and an inode flag for fs-verity.

- Implementing the fsverity_operations to support enabling verity on an
  inode and reading/writing the verity metadata.

- Updating ->write_begin(), ->write_end(), and ->writepages() to support
  writing verity metadata pages.

- Calling the fs-verity hooks for ->open(), ->setattr(), and ->ioctl().

ext4 stores the verity metadata (Merkle tree and fsverity_descriptor)
past the end of the file, starting at the first 64K boundary beyond
i_size.  This approach works because (a) verity files are readonly, and
(b) pages fully beyond i_size aren't visible to userspace but can be
read/written internally by ext4 with only some relatively small changes
to ext4.  This approach avoids having to depend on the EA_INODE feature
and on rearchitecturing ext4's xattr support to support paging
multi-gigabyte xattrs into memory, and to support encrypting xattrs.
Note that the verity metadata *must* be encrypted when the file is,
since it contains hashes of the plaintext data.

This patch incorporates work by Theodore Ts'o and Chandan Rajendra.

Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
2019-08-12 19:33:50 -07:00