ext4_bio_write_page does not need wbc parameter, since its parameter
io contains the io_wbc field. The io::io_wbc is initialized by
ext4_io_submit_init which is called in ext4_writepages and
ext4_writepage functions prior to ext4_bio_write_page.
Therefor, when ext4_bio_write_page is called, wbc info
has already been included in io parameter.
Signed-off-by: NLei Chen <lennychen@tencent.com>
Link: https://lore.kernel.org/r/1607669664-25656-1-git-send-email-lennychen@tencent.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

bv_page can't be NULL in a valid bio_vec, so we can remove the NULL check,
as we did in other places when calling bio_for_each_segment_all() to go
through all bio_vec of a bio.
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NXianting Tian <tian.xianting@h3c.com>
Link: https://lore.kernel.org/r/20201020082201.34257-1-tian.xianting@h3c.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

Wire up ext4 to support inline encryption via the helper functions which
fs/crypto/ now provides.  This includes:

- Adding a mount option 'inlinecrypt' which enables inline encryption
  on encrypted files where it can be used.

- Setting the bio_crypt_ctx on bios that will be submitted to an
  inline-encrypted file.

  Note: submit_bh_wbc() in fs/buffer.c also needed to be patched for
  this part, since ext4 sometimes uses ll_rw_block() on file data.

- Not adding logically discontiguous data to bios that will be submitted
  to an inline-encrypted file.

- Not doing filesystem-layer crypto on inline-encrypted files.
Co-developed-by: NSatya Tangirala <satyat@google.com>
Signed-off-by: NSatya Tangirala <satyat@google.com>
Reviewed-by: NTheodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20200702015607.1215430-5-satyat@google.comSigned-off-by: NEric Biggers <ebiggers@google.com>

Bit spinlocks are problematic if PREEMPT_RT is enabled, because they
disable preemption, which is undesired for latency reasons and breaks when
regular spinlocks are taken within the bit_spinlock locked region because
regular spinlocks are converted to 'sleeping spinlocks' on RT.

PREEMPT_RT replaced the bit spinlocks with regular spinlocks to avoid this
problem. The replacement was done conditionaly at compile time, but
Christoph requested to do an unconditional conversion.

Jan suggested to move the spinlock into a existing padding hole which
avoids a size increase of struct buffer_head on production kernels.

As a benefit the lock gains lockdep coverage.

[ bigeasy: Remove the wrapper and use always spinlock_t and move it into
           the padding hole ]
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>
Link: https://lkml.kernel.org/r/20191118132824.rclhrbujqh4b4g4d@linutronix.de

ext4_writepages() on an encrypted file has to encrypt the data, but it
can't modify the pagecache pages in-place, so it encrypts the data into
bounce pages and writes those instead.  All bounce pages are allocated
from a mempool using GFP_NOFS.

This is not correct use of a mempool, and it can deadlock.  This is
because GFP_NOFS includes __GFP_DIRECT_RECLAIM, which enables the "never
fail" mode for mempool_alloc() where a failed allocation will fall back
to waiting for one of the preallocated elements in the pool.

But since this mode is used for all a bio's pages and not just the
first, it can deadlock waiting for pages already in the bio to be freed.

This deadlock can be reproduced by patching mempool_alloc() to pretend
that pool->alloc() always fails (so that it always falls back to the
preallocations), and then creating an encrypted file of size > 128 KiB.

Fix it by only using GFP_NOFS for the first page in the bio.  For
subsequent pages just use GFP_NOWAIT, and if any of those fail, just
submit the bio and start a new one.

This will need to be fixed in f2fs too, but that's less straightforward.

Fixes: c9af28fd ("ext4 crypto: don't let data integrity writebacks fail with ENOMEM")
Cc: stable@vger.kernel.org
Signed-off-by: NEric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20191231181149.47619-1-ebiggers@kernel.orgSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

Similar to [1] [2], bio_alloc with __GFP_DIRECT_RECLAIM flags
guarantees bio allocation under some given restrictions, as
stated in block/bio.c and fs/direct-io.c So here it's ok to
not check for NULL value from bio_alloc().

[1] https://lore.kernel.org/r/20191030035518.65477-1-gaoxiang25@huawei.com
[2] https://lore.kernel.org/r/20190830162812.GA10694@infradead.org
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20191031092315.139267-1-gaoxiang25@huawei.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

This patch adds the support for blocksize < pagesize for
dioread_nolock feature.

Since in case of blocksize < pagesize, we can have multiple
small buffers of page as unwritten extents, we need to
maintain a vector of these unwritten extents which needs
the conversion after the IO is complete. Thus, we maintain
a list of tuple <offset, size> pair (io_end_vec) for this &
traverse this list to do the unwritten to written conversion.
Signed-off-by: NRitesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/20191016073711.4141-5-riteshh@linux.ibm.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

This patch just brings in the API for conversion of unwritten io_end_vec
extents which will be required for blocksize < pagesize support
for dioread_nolock feature.

No functional changes in this patch.
Signed-off-by: NRitesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/20191016073711.4141-3-riteshh@linux.ibm.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

Let's keep uniform naming convention for ext4_submit_io (io)
& ext4_end_io_t (io_end) structures, to avoid any confusion.
No functionality change in this patch.
Signed-off-by: NRitesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/20191016073711.4141-2-riteshh@linux.ibm.comSigned-off-by: NTheodore Ts'o <tytso@mit.edu>

wbc_account_io() does a very specific job - try to see which cgroup is
actually dirtying an inode and transfer its ownership to the majority
dirtier if needed.  The name is too generic and confusing.  Let's
rename it to something more specific.
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

As an optimization, don't encrypt blocks fully beyond i_size, since
those definitely won't need to be written out.  Also add a comment.

This is in preparation for allowing encryption on ext4 filesystems with
blocksize != PAGE_SIZE.

This is based on work by Chandan Rajendra.
Reviewed-by: NChandan Rajendra <chandan@linux.ibm.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>

Rename fscrypt_encrypt_page() to fscrypt_encrypt_pagecache_blocks() and
redefine its behavior to encrypt all filesystem blocks from the given
region of the given page, rather than assuming that the region consists
of just one filesystem block.  Also remove the 'inode' and 'lblk_num'
parameters, since they can be retrieved from the page as it's already
assumed to be a pagecache page.

This is in preparation for allowing encryption on ext4 filesystems with
blocksize != PAGE_SIZE.

This is based on work by Chandan Rajendra.
Reviewed-by: NChandan Rajendra <chandan@linux.ibm.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>

Currently, bounce page handling for writes to encrypted files is
unnecessarily complicated.  A fscrypt_ctx is allocated along with each
bounce page, page_private(bounce_page) points to this fscrypt_ctx, and
fscrypt_ctx::w::control_page points to the original pagecache page.

However, because writes don't use the fscrypt_ctx for anything else,
there's no reason why page_private(bounce_page) can't just point to the
original pagecache page directly.

Therefore, this patch makes this change.  In the process, it also cleans
up the API exposed to filesystems that allows testing whether a page is
a bounce page, getting the pagecache page from a bounce page, and
freeing a bounce page.
Reviewed-by: NChandan Rajendra <chandan@linux.ibm.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>

We only have two callers that need the integer loop iterator, and they
can easily maintain it themselves.
Suggested-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Acked-by: NDavid Sterba <dsterba@suse.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Acked-by: NColy Li <colyli@suse.de>
Reviewed-by: NMatthew Wilcox <willy@infradead.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This patch introduces one extra iterator variable to bio_for_each_segment_all(),
then we can allow bio_for_each_segment_all() to iterate over multi-page bvec.

Given it is just one mechannical & simple change on all bio_for_each_segment_all()
users, this patch does tree-wide change in one single patch, so that we can
avoid to use a temporary helper for this conversion.
Reviewed-by: NOmar Sandoval <osandov@fb.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NMing Lei <ming.lei@redhat.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Now, we have already handle all cases of forgetting buffer in
jbd2_journal_forget(), the buffer should not be mapped to blockdevice
when reallocating it. So this patch remove all clean_bdev_aliases() and
clean_bdev_bh_alias() calls which were invoked by ext4 explicitly.
Suggested-by: NJan Kara <jack@suse.cz>
Signed-off-by: Nzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>

In order to have a common code base for fscrypt "post read" processing
for all filesystems which support encryption, this commit removes
filesystem specific build config option (e.g. CONFIG_EXT4_FS_ENCRYPTION)
and replaces it with a build option (i.e. CONFIG_FS_ENCRYPTION) whose
value affects all the filesystems making use of fscrypt.
Reviewed-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NChandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>

This commit removes the ext4 specific ext4_encrypted_inode() and makes
use of the generic IS_ENCRYPTED() macro to check for the encryption
status of an inode.
Reviewed-by: NEric Biggers <ebiggers@google.com>
Signed-off-by: NChandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>

One of the goals of this series is to remove a separate reference to
the css of the bio. This can and should be accessed via bio_blkcg(). In
this patch, wbc_init_bio() now requires a bio to have a device
associated with it.
Signed-off-by: NDennis Zhou <dennis@kernel.org>
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This reverts a series committed earlier due to null pointer exception
bug report in [1]. It seems there are edge case interactions that I did
not consider and will need some time to understand what causes the
adverse interactions.

The original series can be found in [2] with a follow up series in [3].

[1] https://www.spinics.net/lists/cgroups/msg20719.html
[2] https://lore.kernel.org/lkml/20180911184137.35897-1-dennisszhou@gmail.com/
[3] https://lore.kernel.org/lkml/20181020185612.51587-1-dennis@kernel.org/

This reverts the following commits:
d459d853, b2c3fa54, 101246ec, b3b9f24f, e2b09899,
f0fcb3ec, c839e7a0, bdc24917, 74b7c02a, 5bf9a1f3,
a7b39b4e, 07b05bcc, 49f4c2dc, 27e6fa99Signed-off-by: NDennis Zhou <dennis@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

One of the goals of this series is to remove a separate reference to
the css of the bio. This can and should be accessed via bio_blkcg. In
this patch, the wbc_init_bio call is changed such that it must be called
after a queue has been associated with the bio.
Signed-off-by: NDennis Zhou <dennisszhou@gmail.com>
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This way we don't need a block_device structure to submit I/O.  The
block_device has different life time rules from the gendisk and
request_queue and is usually only available when the block device node
is open.  Other callers need to explicitly create one (e.g. the lightnvm
passthrough code, or the new nvme multipathing code).

For the actual I/O path all that we need is the gendisk, which exists
once per block device.  But given that the block layer also does
partition remapping we additionally need a partition index, which is
used for said remapping in generic_make_request.

Note that all the block drivers generally want request_queue or
sometimes the gendisk, so this removes a layer of indirection all
over the stack.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Reviewed-by: NAndreas Dilger <adilger@dilger.ca>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Replace bi_error with a new bi_status to allow for a clear conversion.
Note that device mapper overloaded bi_error with a private value, which
we'll have to keep arround at least for now and thus propagate to a
proper blk_status_t value.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

Add fallback code and a WARN_ONCE() call instead of a BUG_ON() in
the ext4_end_bio() function.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

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: NEric Biggers <ebiggers@google.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Add a shutdown bit that will cause ext4 processing to fail immediately
with EIO.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Avoid re-use of page index as tweak for AES-XTS when multiple parts of
same page are encrypted. This will happen on multiple (partial) calls of
fscrypt_encrypt_page on same page.
page->index is only valid for writeback pages.
Signed-off-by: NDavid Gstir <david@sigma-star.at>
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Not all filesystems work on full pages, thus we should allow them to
hand partial pages to fscrypt for en/decryption.
Signed-off-by: NDavid Gstir <david@sigma-star.at>
Signed-off-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Add a helper function that clears buffer heads from a block device
aliasing passed bh. Use this helper function from filesystems instead of
the original unmap_underlying_metadata() to save some boiler plate code
and also have a better name for the functionalily since it is not
unmapping anything for a *long* time.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJens Axboe <axboe@fb.com>

Remove the WRITE_* and READ_SYNC wrappers, and just use the flags
directly.  Where applicable this also drops usage of the
bio_set_op_attrs wrapper.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

The mapping_set_error() helper sets the correct AS_ flag for the mapping
so there is no reason to open code it.  Use the helper directly.

[akpm@linux-foundation.org: be honest about conversion from -ENXIO to -EIO]
Link: http://lkml.kernel.org/r/20160912111608.2588-2-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NEric Engestrom <eric.engestrom@imgtec.com>

This patch removes the most parts of internal crypto codes.
And then, it modifies and adds some ext4-specific crypt codes to use the generic
facility.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

This patch converts the simple bi_rw use cases in the block,
drivers, mm and fs code to set/get the bio operation using
bio_set_op_attrs/bio_op

These should be simple one or two liner cases, so I just did them
in one patch. The next patches handle the more complicated
cases in a module per patch.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

This has callers of submit_bio/submit_bio_wait set the bio->bi_rw
instead of passing it in. This makes that use the same as
generic_make_request and how we set the other bio fields.
Signed-off-by: NMike Christie <mchristi@redhat.com>

Fixed up fs/ext4/crypto.c
Signed-off-by: NJens Axboe <axboe@fb.com>

ext4_io_submit() used to check for EOPNOTSUPP after bio submission,
which is why it had to get an extra reference to the bio before
submitting it. But since we no longer touch the bio after submission,
get rid of the redundant get/put of the bio. If we do get the extra
reference, we enter the slower path of having to flag this bio as now
having external references.
Signed-off-by: NJens Axboe <axboe@fb.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We should be testing for -ENOMEM but the minus sign is missing.

Fixes: c9af28fd ('ext4 crypto: don't let data integrity writebacks fail with ENOMEM')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>