The documentation is more appropriate for the administrator than for
the internal kernel API section it is currently in.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Christian Brauner <christian@brauner.io>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
After the update to use nlm_lockowners for the NLM server, there are no
more users of lm_compare_owner and lm_owner_key.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This patch allows fallocate to allocate physical blocks for pinned file.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
We need to derive the mount pointer from a buffer in a lot of place.
Add a direct pointer to short cut the pointer chasing.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Document how to test ext4, f2fs, and ubifs encryption with xfstests.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
fscrypt only uses SHA-256 for AES-128-CBC-ESSIV, which isn't the default
and is only recommended on platforms that have hardware accelerated
AES-CBC but not AES-XTS. There's no link-time dependency, since SHA-256
is requested via the crypto API on first use.
To reduce bloat, we should limit FS_ENCRYPTION to selecting the default
algorithms only. SHA-256 by itself isn't that much bloat, but it's
being discussed to move ESSIV into a crypto API template, which would
incidentally bring in other things like "authenc" support, which would
all end up being built-in since FS_ENCRYPTION is now a bool.
For Adiantum encryption we already just document that users who want to
use it have to enable CONFIG_CRYPTO_ADIANTUM themselves. So, let's do
the same for AES-128-CBC-ESSIV and CONFIG_CRYPTO_SHA256.
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Clearify d_make_root() usage, error handling and cleanup
requirements.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
There's no need to use a .rst on Sphinx toc tables. As most of
the Documentation don't use, remove the remaing occurrences.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Convert the cgroup-v1 files to ReST format, in order to
allow a later addition to the admin-guide.
The conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
The conversion is actually:
- add blank lines and indentation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
A recent documentation conversion renamed this file but forgot
to update the links.
Fixes: af96c1e304 ("docs: filesystems: vfs: Convert vfs.txt to RST")
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently vfs.rst does not render well into HTML the method descriptions
for VFS data structures. We can improve the HTML output by putting the
description string on a new line following the method name.
Suggested-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This extends the checkpoint option to allow checkpoint=disable:%u[%]
This allows you to specify what how much of the disk you are willing
to lose access to while mounting with checkpoint=disable. If the amount
lost would be higher, the mount will return -EAGAIN. This can be given
as a percent of total space, or in blocks.
Currently, we need to run garbage collection until the amount of holes
is smaller than the OVP space. With the new option, f2fs can mark
space as unusable up front instead of requiring garbage collection until
the number of holes is small enough.
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
The single user of debugfs_create_u32_array() does not care about the
return value of it, so make it return void as there is no need to do
anything with the return value.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch cleans up documentation to cover missing sysfs entries.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
vfs.txt is currently stale. If we convert it to RST this is a good
first step in the process of getting the VFS documentation up to date.
This patch does the following (all as a single patch so as not to
introduce any new SPHINX build warnings)
- Use '.. code-block:: c' for C code blocks and indent the code blocks.
- Use double backticks for struct member descriptions.
- Fix a couple of build warnings by guarding pointers (*) with double
backticks .e.g ``*ptr``.
- Add vfs to Documentation/filesystems/index.rst
The member descriptions paragraph indentation was not touched. It is
not pretty but these do not cause build warnings. These descriptions
all need updating anyways so leave it as it is for now.
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
There are bunch of places with 8 spaces, in preparation for correctly
indenting all code snippets (during conversion to RST) change these to
use tabspaces.
This patch is whitespace only.
Convert instances of 8 consecutive spaces to a single tabspace.
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently file pre-amble contains custom indentation. RST is not going
to like this, lets left-align the text. Put the copyright notices in a
list in preparation for converting document to RST.
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently the licence is indicated via a custom string. We have SPDX
license identifiers now for this task.
Use SPDX license identifier matching current license string.
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Kernel RST has a preferred heading adornment scheme. Currently all the
heading adornments follow this scheme except the document heading.
Use correct heading adornment for initial heading.
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently spacing before and after headings is non-uniform. Use two
blank lines before a heading and one after the heading.
Use uniform spacing around headings.
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
In preparation for conversion to RST format use the kernels favoured
documentation column width. If we are going to do this we might as well
do it thoroughly. Just do the paragraphs (not the indented stuff), the
rest will be done during indentation fix up patch.
This patch is whitespace only, no textual changes.
Use 72 character column width for all paragraph sections.
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently sometimes document has a single space after a period and
sometimes it has double. Whichever we use it should be uniform.
Use double space after period, be uniform.
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Currently the file has a bunch of spaces before tabspaces. This is a
nuisance when patching the file because they show up whenever we touch
these lines. Let's just fix them all now in preparation for doing the
RST conversion.
Remove spaces before tabspaces.
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Tobin C. Harding <tobin@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
ext2 support user/group disk quota by specifying
usrquota/grpquota option on mount, so fix the
description in the doc properly.
Signed-off-by: Chengguang Xu <cgxu519@zoho.com.cn>
Signed-off-by: Jan Kara <jack@suse.cz>
Pull misc vfs updates from Al Viro:
"Assorted stuff, with no common topic whatsoever..."
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
libfs: document simple_get_link()
Documentation/filesystems/Locking: fix ->get_link() prototype
Documentation/filesystems/vfs.txt: document how ->i_link works
Documentation/filesystems/vfs.txt: remove bogus "Last updated" date
fs: use timespec64 in relatime_need_update
fs/block_dev.c: remove unused include
Pull misc dcache updates from Al Viro:
"Most of this pile is putting name length into struct name_snapshot and
making use of it.
The beginning of this series ("ovl_lookup_real_one(): don't bother
with strlen()") ought to have been split in two (separate switch of
name_snapshot to struct qstr from overlayfs reaping the trivial
benefits of that), but I wanted to avoid a rebase - by the time I'd
spotted that it was (a) in -next and (b) close to 5.1-final ;-/"
* 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
audit_compare_dname_path(): switch to const struct qstr *
audit_update_watch(): switch to const struct qstr *
inotify_handle_event(): don't bother with strlen()
fsnotify: switch send_to_group() and ->handle_event to const struct qstr *
fsnotify(): switch to passing const struct qstr * for file_name
switch fsnotify_move() to passing const struct qstr * for old_name
ovl_lookup_real_one(): don't bother with strlen()
sysv: bury the broken "quietly truncate the long filenames" logics
nsfs: unobfuscate
unexport d_alloc_pseudo()
Pull driver core/kobject updates from Greg KH:
"Here is the "big" set of driver core patches for 5.2-rc1
There are a number of ACPI patches in here as well, as Rafael said
they should go through this tree due to the driver core changes they
required. They have all been acked by the ACPI developers.
There are also a number of small subsystem-specific changes in here,
due to some changes to the kobject core code. Those too have all been
acked by the various subsystem maintainers.
As for content, it's pretty boring outside of the ACPI changes:
- spdx cleanups
- kobject documentation updates
- default attribute groups for kobjects
- other minor kobject/driver core fixes
All have been in linux-next for a while with no reported issues"
* tag 'driver-core-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (47 commits)
kobject: clean up the kobject add documentation a bit more
kobject: Fix kernel-doc comment first line
kobject: Remove docstring reference to kset
firmware_loader: Fix a typo ("syfs" -> "sysfs")
kobject: fix dereference before null check on kobj
Revert "driver core: platform: Fix the usage of platform device name(pdev->name)"
init/config: Do not select BUILD_BIN2C for IKCONFIG
Provide in-kernel headers to make extending kernel easier
kobject: Improve doc clarity kobject_init_and_add()
kobject: Improve docs for kobject_add/del
driver core: platform: Fix the usage of platform device name(pdev->name)
livepatch: Replace klp_ktype_patch's default_attrs with groups
cpufreq: schedutil: Replace default_attrs field with groups
padata: Replace padata_attr_type default_attrs field with groups
irqdesc: Replace irq_kobj_type's default_attrs field with groups
net-sysfs: Replace ktype default_attrs field with groups
block: Replace all ktype default_attrs with groups
samples/kobject: Replace foo_ktype's default_attrs field with groups
kobject: Add support for default attribute groups to kobj_type
driver core: Postpone DMA tear-down until after devres release for probe failure
...
Pull vfs stable fodder fixes from Al Viro:
- acct_on() fix for deadlock caught by overlayfs folks
- autofs RCU use-after-free SNAFU (->d_manage() can be called
locklessly, so we need to RCU-delay freeing the objects it looks at)
- (hopefully) the end of "do we need freeing this dentry RCU-delayed"
whack-a-mole.
* 'stable-fodder' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
autofs: fix use-after-free in lockless ->d_manage()
dcache: sort the freeing-without-RCU-delay mess for good.
acct_on(): don't mess with freeze protection
Userspace processes often have multiple allocators that each do
anonymous mmaps to get memory. When examining memory usage of
individual processes or systems as a whole, it is useful to be
able to break down the various heaps that were allocated by
each layer and examine their size, RSS, and physical memory
usage.
This patch adds a user pointer to the shared union in
vm_area_struct that points to a null terminated string inside
the user process containing a name for the vma. vmas that
point to the same address will be merged, but vmas that
point to equivalent strings at different addresses will
not be merged.
Userspace can set the name for a region of memory by calling
prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, start, len, (unsigned long)name);
Setting the name to NULL clears it.
The names of named anonymous vmas are shown in /proc/pid/maps
as [anon:<name>] and in /proc/pid/smaps in a new "Name" field
that is only present for named vmas. If the userspace pointer
is no longer valid all or part of the name will be replaced
with "<fault>".
The idea to store a userspace pointer to reduce the complexity
within mm (at the expense of the complexity of reading
/proc/pid/mem) came from Dave Hansen. This results in no
runtime overhead in the mm subsystem other than comparing
the anon_name pointers when considering vma merging. The pointer
is stored in a union with fieds that are only used on file-backed
mappings, so it does not increase memory usage.
Includes fix from Jed Davis <jld@mozilla.com> for typo in
prctl_set_vma_anon_name, which could attempt to set the name
across two vmas at the same time due to a typo, which might
corrupt the vma list. Fix it to use tmp instead of end to limit
the name setting to a single vma at a time.
Bug: 120441514
Change-Id: I9aa7b6b5ef536cd780599ba4e2fba8ceebe8b59f
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
[AmitP: Fix get_user_pages_remote() call to align with upstream commit
5b56d49fc3 ("mm: add locked parameter to get_user_pages_remote()")]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
A lot of ->destroy_inode() instances end with call_rcu() of a callback
that does RCU-delayed part of freeing. Introduce a new method for
doing just that, with saner signature.
Rules:
->destroy_inode ->free_inode
f g immediate call of f(),
RCU-delayed call of g()
f NULL immediate call of f(),
no RCU-delayed calls
NULL g RCU-delayed call of g()
NULL NULL RCU-delayed default freeing
IOW, NULL ->free_inode gives the same behaviour as now.
Note that NULL, NULL is equivalent to NULL, free_inode_nonrcu; we could
mandate the latter form, but that would have very little benefit beyond
making rules a bit more symmetric. It would break backwards compatibility,
require extra boilerplate and expected semantics for (NULL, NULL) pair
would have no use whatsoever...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This file has actually been updated over 100 times since the claimed
"Last updated" date.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Since commit ff9fb72bc0 ("debugfs: return error values, not NULL")
these helper functions do not return NULL anymore (with the exception
of debugfs_create_u32_array()).
Fixes: ff9fb72bc0 ("debugfs: return error values, not NULL")
Signed-off-by: Ronald Tschalär <ronald@innovation.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No modular uses since introducion of alloc_file_pseudo(),
and the only non-modular user not in alloc_file_pseudo()
had actually been wrong - should've been d_alloc_anon().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
For lockless accesses to dentries we don't have pinned we rely
(among other things) upon having an RCU delay between dropping
the last reference and actually freeing the memory.
On the other hand, for things like pipes and sockets we neither
do that kind of lockless access, nor want to deal with the
overhead of an RCU delay every time a socket gets closed.
So delay was made optional - setting DCACHE_RCUACCESS in ->d_flags
made sure it would happen. We tried to avoid setting it unless
we knew we need it. Unfortunately, that had led to recurring
class of bugs, in which we missed the need to set it.
We only really need it for dentries that are created by
d_alloc_pseudo(), so let's not bother with trying to be smart -
just make having an RCU delay the default. The ones that do
*not* get it set the replacement flag (DCACHE_NORCU) and we'd
better use that sparingly. d_alloc_pseudo() is the only
such user right now.
FWIW, the race that finally prompted that switch had been
between __lock_parent() of immediate subdirectory of what's
currently the root of a disconnected tree (e.g. from
open-by-handle in progress) racing with d_splice_alias()
elsewhere picking another alias for the same inode, either
on outright corrupted fs image, or (in case of open-by-handle
on NFS) that subdirectory having been just moved on server.
It's not easy to hit, so the sky is not falling, but that's
not the first race on similar missed cases and the logics
for settinf DCACHE_RCUACCESS has gotten ridiculously
convoluted.
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
