Commit Graph

110 Commits

Author SHA1 Message Date
Leon Romanovsky 40c8ee67cf init: don't panic if mount_nodev_root failed
Attempt to mount 9p file system as root gives the following kernel panic:

 9pnet_virtio: no channels available for device root
 Kernel panic - not syncing: VFS: Unable to mount root "root" (9p), err=-2
 CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.15.0-rc1+ #127
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
 Call Trace:
  dump_stack_lvl+0x45/0x59
  panic+0x1e2/0x44b
  ? __warn_printk+0xf3/0xf3
  ? free_unref_page+0x2d4/0x4a0
  ? trace_hardirqs_on+0x32/0x120
  ? free_unref_page+0x2d4/0x4a0
  mount_root+0x189/0x1e0
  prepare_namespace+0x136/0x165
  kernel_init_freeable+0x3b8/0x3cb
  ? rest_init+0x2e0/0x2e0
  kernel_init+0x19/0x130
  ret_from_fork+0x1f/0x30
 Kernel Offset: disabled
 ---[ end Kernel panic - not syncing: VFS: Unable to mount root "root" (9p), err=-2 ]---

QEMU command line:
 "qemu-system-x86_64 -append root=/dev/root rw rootfstype=9p rootflags=trans=virtio ..."

This error is because root_device_name is truncated in prepare_namespace() from
being "/dev/root" to be "root" prior to call to mount_nodev_root().

As a solution, don't treat errors in mount_nodev_root() as errors that
require panics and allow failback to the mount flow that existed before
patch citied in Fixes tag.

Fixes: f9259be6a9 ("init: allow mounting arbitrary non-blockdevice filesystems as root")
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-09-19 22:24:52 -04:00
Vivek Goyal b51593c4cd init/do_mounts.c: Harden split_fs_names() against buffer overflow
split_fs_names() currently takes comma separate list of filesystems
and converts it into individual filesystem strings. Pleaces these
strings in the input buffer passed by caller and returns number of
strings.

If caller manages to pass input string bigger than buffer, then we
can write beyond the buffer. Or if string just fits buffer, we will
still write beyond the buffer as we append a '\0' byte at the end.

Pass size of input buffer to split_fs_names() and put enough checks
in place so such buffer overrun possibilities do not occur.

This patch does few things.

- Add a parameter "size" to split_fs_names(). This specifies size
  of input buffer.

- Use strlcpy() (instead of strcpy()) so that we can't go beyond
  buffer size. If input string "names" is larger than passed in
  buffer, input string will be truncated to fit in buffer.

- Stop appending extra '\0' character at the end and avoid one
  possibility of going beyond the input buffer size.

- Do not use extra loop to count number of strings.

- Previously if one passed "rootfstype=foo,,bar", split_fs_names()
  will return only 1 string "foo" (and "bar" will be truncated
  due to extra ,). After this patch, now split_fs_names() will
  return 3 strings ("foo", zero-sized-string, and "bar").

  Callers of split_fs_names() have been modified to check for
  zero sized string and skip to next one.

Reported-by: xu xin <xu.xin16@zte.com.cn>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-09-19 22:24:49 -04:00
Linus Torvalds e2e694b9e6 Merge branch 'work.init' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull root filesystem type handling updates from Al Viro:
 "Teach init/do_mounts.c to handle non-block filesystems, hopefully
  preventing even more special-cased kludges (such as root=/dev/nfs,
  etc)"

* 'work.init' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: simplify get_filesystem_list / get_all_fs_names
  init: allow mounting arbitrary non-blockdevice filesystems as root
  init: split get_fs_names
2021-09-09 12:38:18 -07:00
Christoph Hellwig c4b2b7d150 block: remove CONFIG_DEBUG_BLOCK_EXT_DEVT
This might have been a neat debug aid when the extended dev_t was
added, but that time is long gone.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210824075216.1179406-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-08-24 06:42:40 -06:00
Christoph Hellwig 6e7c1770a2 fs: simplify get_filesystem_list / get_all_fs_names
Just output the '\0' separate list of supported file systems for block
devices directly rather than going through a pointless round of string
manipulation.

Based on an earlier patch from Al Viro <viro@zeniv.linux.org.uk>.

Vivek:
Modified list_bdev_fs_names() and split_fs_names() to return number of
null terminted strings to caller. Callers now use that information to
loop through all the strings instead of relying on one extra null char
being present at the end.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-08-23 01:25:40 -04:00
Christoph Hellwig f9259be6a9 init: allow mounting arbitrary non-blockdevice filesystems as root
Currently the only non-blockdevice filesystems that can be used as the
initial root filesystem are NFS and CIFS, which use the magic
"root=/dev/nfs" and "root=/dev/cifs" syntax that requires the root
device file system details to come from filesystem specific kernel
command line options.

Add a little bit of new code that allows to just pass arbitrary
string mount options to any non-blockdevice filesystems so that it can
be mounted as the root file system.

For example a virtiofs root file system can be mounted using the
following syntax:

"root=myfs rootfstype=virtiofs rw"

Based on an earlier patch from Vivek Goyal <vgoyal@redhat.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-08-23 01:25:40 -04:00
Christoph Hellwig e24d12b744 init: split get_fs_names
Split get_fs_names into one function that splits up the command line
argument, and one that gets the list of all registered file systems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-08-23 01:25:40 -04:00
Christoph Hellwig c97d93c31e block: factor out a part_devt helper
Add a helper to find the dev_t for a disk + partno tuple.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20210525061301.2242282-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-01 07:45:49 -06:00
Christoph Hellwig 0d02129e76 block: merge struct block_device and struct hd_struct
Instead of having two structures that represent each block device with
different life time rules, merge them into a single one.  This also
greatly simplifies the reference counting rules, as we can use the inode
reference count as the main reference count for the new struct
block_device, with the device model reference front ending it for device
model interaction.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig 41e5c81984 block: remove the partno field from struct hd_struct
Just use the bd_partno field in struct block_device everywhere.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig 231926dbf0 block: move the partition_meta_info to struct block_device
Move the partition_meta_info to struct block_device in preparation for
killing struct hd_struct.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:40 -07:00
Christoph Hellwig 013b0e96ae init: cleanup match_dev_by_uuid and match_dev_by_label
Avoid a totally pointless goto label, and use the same style of
comparism for both helpers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:39 -07:00
Christoph Hellwig e036bb8e0c init: refactor devt_from_partuuid
The code in devt_from_partuuid is very convoluted.  Refactor a bit by
sanitizing the goto and variable name usage.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:39 -07:00
Christoph Hellwig c2637e80a0 init: refactor name_to_dev_t
Split each case into a self-contained helper, and move the block
dependent code entirely under the pre-existing #ifdef CONFIG_BLOCK.
This allows to remove the blk_lookup_devt stub in genhd.h.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-12-01 14:53:39 -07:00
Christoph Hellwig 4b7ca5014c init: add an init_chroot helper
Add a simple helper to chroot with a kernel space file name and switch
the early init code over to it.  Remove the now unused ksys_chroot.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-31 08:17:52 +02:00
Christoph Hellwig db63f1e315 init: add an init_chdir helper
Add a simple helper to chdir with a kernel space file name and switch
the early init code over to it.  Remove the now unused ksys_chdir.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-31 08:17:52 +02:00
Christoph Hellwig c60166f042 init: add an init_mount helper
Like do_mount, but takes a kernel pointer for the destination path.
Switch over the mounts in the init code and devtmpfs to it, which
just happen to work due to the implicit set_fs(KERNEL_DS) during early
init right now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2020-07-31 08:17:51 +02:00
Christoph Hellwig c8376994c8 initrd: remove support for multiple floppies
Remove the special handling for multiple floppies in the initrd code.
No one should be using floppies for booting these days. (famous last
words..)

Includes a spelling fix from Colin Ian King <colin.king@canonical.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-30 08:22:33 +02:00
Christoph Hellwig 4f5b246b37 md: move the early init autodetect code to drivers/md/
Just like the NFS and CIFS root code this better lives with the
driver it is tightly integrated with.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-07-16 15:34:47 +02:00
Christoph Hellwig ea3edd4dc2 block: remove __bdevname
There is no good reason for __bdevname to exist.  Just open code
printing the string in the callers.  For three of them the format
string can be trivially merged into existing printk statements,
and in init/do_mounts.c we can at least do the scnprintf once at
the start of the function, and unconditional of CONFIG_BLOCK to
make the output for tiny configfs a little more helpful.

Acked-by: Theodore Ts'o <tytso@mit.edu> # for ext4
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-03-24 07:57:07 -06:00
Linus Torvalds 7de7de7ca0 Fix root mounting with no mount options
The "trivial conversion" in commit cccaa5e335 ("init: use do_mount()
instead of ksys_mount()") was totally broken, since it didn't handle the
case of a NULL mount data pointer.  And while I had "tested" it (and
presumably Dominik had too) that bug was hidden by me having options.

Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Reported-by: Ondřej Jirman <megi@xff.cz>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-and-tested-by: Borislav Petkov <bp@suse.de>
Tested-by: Chris Clayton <chris2553@googlemail.com>
Tested-by: Eric Biggers <ebiggers@kernel.org>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Guido Günther <agx@sigxcpu.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-16 08:42:39 -08:00
Dominik Brodowski cccaa5e335 init: use do_mount() instead of ksys_mount()
In prepare_namespace(), do_mount() can be used instead of ksys_mount()
as the first and third argument are const strings in the kernel, the
second and fourth argument are passed through anyway, and the fifth
argument is NULL.

In do_mount_root(), ksys_mount() is called with the first and third
argument being already kernelspace strings, which do not need to be
copied over from userspace to kernelspace (again). The second and
fourth arguments are passed through to do_mount() anyway. The fifth
argument, while already residing in kernelspace, needs to be put into
a page of its own. Then, do_mount() can be used instead of
ksys_mount().

Once this is done, there are no in-kernel users to ksys_mount() left,
which can therefore be removed.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2019-12-12 14:50:05 +01:00
Dominik Brodowski 5e787dbf65 devtmpfs: use do_mount() instead of ksys_mount()
In devtmpfs, do_mount() can be called directly instead of complex wrapping
by ksys_mount():
- the first and third arguments are const strings in the kernel,
  and do not need to be copied over from userspace;
- the fifth argument is NULL, and therefore no page needs to be
  copied over from userspace;
- the second and fourth argument are passed through anyway.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2019-12-12 14:49:57 +01:00
Paulo Alcantara (SUSE) 8902dd5260 init: Support mounting root file systems over SMB
Add a new virtual device named /dev/cifs (0xfe) to tell the kernel to
mount the root file system over the network by using SMB protocol.

cifs_root_data() will be responsible to retrieve the parsed
information of the new command-line option (cifsroot=) and then call
do_mount_root() with the appropriate mount options for cifs.ko.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-02 12:15:15 -04:00
David Howells f32356261d vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API
Convert the ramfs, shmem, tmpfs, devtmpfs and rootfs filesystems to the new
internal mount API as the old one will be obsoleted and removed.  This
allows greater flexibility in communication of mount parameters between
userspace, the VFS and the filesystem.

See Documentation/filesystems/mount_api.txt for more information.

Note that tmpfs is slightly tricky as it can contain embedded commas, so it
can't be trivially split up using strsep() to break on commas in
generic_parse_monolithic().  Instead, tmpfs has to supply its own generic
parser.

However, if tmpfs changes, then devtmpfs and rootfs, which are wrappers
around tmpfs or ramfs, must change too - and thus so must ramfs, so these
had to be converted also.

[AV: rewritten]

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Hugh Dickins <hughd@google.com>
cc: linux-mm@kvack.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-09-12 21:05:34 -04:00
Al Viro 7e30d2a5eb make shmem_fill_super() static
... have callers use shmem_mount()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-09-05 14:34:28 -04:00
Al Viro df02450217 make ramfs_fill_super() static
all users should just call ramfs_mount()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-09-05 14:34:27 -04:00
Linus Torvalds 933a90bf4f Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount updates from Al Viro:
 "The first part of mount updates.

  Convert filesystems to use the new mount API"

* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  mnt_init(): call shmem_init() unconditionally
  constify ksys_mount() string arguments
  don't bother with registering rootfs
  init_rootfs(): don't bother with init_ramfs_fs()
  vfs: Convert smackfs to use the new mount API
  vfs: Convert selinuxfs to use the new mount API
  vfs: Convert securityfs to use the new mount API
  vfs: Convert apparmorfs to use the new mount API
  vfs: Convert openpromfs to use the new mount API
  vfs: Convert xenfs to use the new mount API
  vfs: Convert gadgetfs to use the new mount API
  vfs: Convert oprofilefs to use the new mount API
  vfs: Convert ibmasmfs to use the new mount API
  vfs: Convert qib_fs/ipathfs to use the new mount API
  vfs: Convert efivarfs to use the new mount API
  vfs: Convert configfs to use the new mount API
  vfs: Convert binfmt_misc to use the new mount API
  convenience helper: get_tree_single()
  convenience helper get_tree_nodev()
  vfs: Kill sget_userns()
  ...
2019-07-19 10:42:02 -07:00
Al Viro 037f11b475 mnt_init(): call shmem_init() unconditionally
No point having two call sites (earlier in init_rootfs() from
mnt_init() in case we are going to use shmem-style rootfs,
later from do_basic_setup() unconditionally), along with the
logics in shmem_init() itself to make the second call a no-op...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-04 22:01:59 -04:00
Al Viro fd3e007f6c don't bother with registering rootfs
init_mount_tree() can get to rootfs_fs_type directly and that simplifies
a lot of things.  We don't need to register it, we don't need to look
it up *and* we don't need to bother with preventing subsequent userland
mounts.  That's the way we should've done that from the very beginning.

There is a user-visible change, namely the disappearance of "rootfs"
from /proc/filesystems.  Note that it's been unmountable all along
and it didn't show up in /proc/mounts; however, it *is* a user-visible
change and theoretically some script might've been using its presence
in /proc/filesystems to tell 2.4.11+ from earlier kernels.

*IF* any complaints about behaviour change do show up, we could fake
it in /proc/filesystems.  I very much doubt we'll have to, though.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-04 22:01:59 -04:00
Al Viro 14a253ce42 init_rootfs(): don't bother with init_ramfs_fs()
the only thing done by the latter is making ramfs visible
to mount(2); we don't need it there - rootfs is separate
and, in fact, made visible to mount(2) in the same init_rootfs().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-07-04 22:01:59 -04:00
Thomas Gleixner 457c899653 treewide: Add SPDX license identifier for missed files
Add SPDX license identifiers to all files which:

 - Have no license information of any form

 - Have EXPORT_.*_SYMBOL_GPL inside which was used in the
   initial scan/conversion to ignore the file

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:45 +02:00
David Howells e262e32d6b vfs: Suppress MS_* flag defs within the kernel unless explicitly enabled
Only the mount namespace code that implements mount(2) should be using the
MS_* flags.  Suppress them inside the kernel unless uapi/linux/mount.h is
included.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: David Howells <dhowells@redhat.com>
2018-12-20 16:32:56 +00:00
Nikolaus Voss f027c34d84 init/do_mounts.c: add root=PARTLABEL=<name> support
Support referencing the root partition label from GPT as argument
to the root= option on the kernel command line in analogy to
referencing the partition uuid as root=PARTUUID=<uuid>.

Specifying the partition label instead of the uuid is often much
easier, e.g. in embedded environments when there is an
A/B rootfs partition scheme for interruptible firmware updates
(i.e. rootfsA/ rootfsB).

The partition label can be queried with the blkid command.

Link: http://lkml.kernel.org/r/20180822060904.828E510665E@pc-niv.weinmann.com
Signed-off-by: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Sasha Levin <Alexander.Levin@microsoft.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-10-31 08:54:13 -07:00
Luc Van Oostenryck 6ad018e3ca init/: remove ineffective sparse disabling
Sparse checking used to be disabled on init/do_mounts.c and a few related
files because "Many of the syscalls used in this file expect some of the
arguments to be __user pointers not __kernel pointers".

However since 28128c61e ("kconfig.h: Include compiler types to avoid
missed struct attributes") the checks are, in fact, not disabled anymore
because of the more early include of "linux/compiler_types.h"

So remove the now ineffective #undefery that was done to disable these
warnings, as well as the associated comment.

Link: http://lkml.kernel.org/r/20180617115355.53799-1-luc.vanoostenryck@gmail.com
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:49 -07:00
Dominik Brodowski 3ce4a7bf66 fs: add ksys_read() helper; remove in-kernel calls to sys_read()
Using this helper allows us to avoid the in-kernel calls to the
sys_read() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it
uses the same calling convention as sys_read().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:04 +02:00
Dominik Brodowski cbb60b924b fs: add ksys_ioctl() helper; remove in-kernel calls to sys_ioctl()
Using this helper allows us to avoid the in-kernel calls to the
sys_ioctl() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it
uses the same calling convention as sys_ioctl().

After careful review, at least some of these calls could be converted
to do_vfs_ioctl() in future.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:03 +02:00
Dominik Brodowski bae217ea8c fs: add ksys_open() wrapper; remove in-kernel calls to sys_open()
Using this wrapper allows us to avoid the in-kernel calls to the
sys_open() syscall. The ksys_ prefix denotes that this function is meant
as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_open().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:01 +02:00
Dominik Brodowski 2ca2a09d62 fs: add ksys_close() wrapper; remove in-kernel calls to sys_close()
Using the ksys_close() wrapper allows us to get rid of in-kernel calls
to the sys_close() syscall. The ksys_ prefix denotes that this function
is meant as a drop-in replacement for the syscall. In particular, it
uses the same calling convention as sys_close(), with one subtle
difference:

The few places which checked the return value did not care about the return
value re-writing in sys_close(), so simply use a wrapper around
__close_fd().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:00 +02:00
Dominik Brodowski 447016e968 fs: add ksys_chdir() helper; remove in-kernel calls to sys_chdir()
Using this helper allows us to avoid the in-kernel calls to the sys_chdir()
syscall. The ksys_ prefix denotes that this function is meant as a drop-in
replacement for the syscall. In particular, it uses the same calling
convention as sys_chdir().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:51 +02:00
Dominik Brodowski a16fe33ab5 fs: add ksys_chroot() helper; remove-in kernel calls to sys_chroot()
Using this helper allows us to avoid the in-kernel calls to the
sys_chroot() syscall. The ksys_ prefix denotes that this function is
meant as a drop-in replacement for the syscall. In particular, it uses the
same calling convention as sys_chroot().

In the near future, the fs-external callers of ksys_chroot() should be
converted to use kern_path()/set_fs_root() directly. Then ksys_chroot()
can be moved within sys_chroot() again.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:50 +02:00
Dominik Brodowski 312db1aa1d fs: add ksys_mount() helper; remove in-kernel calls to sys_mount()
Using this helper allows us to avoid the in-kernel calls to the sys_mount()
syscall. The ksys_ prefix denotes that this function is meant as a drop-in
replacement for the syscall. In particular, it uses the same calling
convention as sys_mount().

In the near future, all callers of ksys_mount() should be converted to call
do_mount() directly.

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:48 +02:00
Levin, Alexander (Sasha Levin) 75f296d93b kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK
Convert all allocations that used a NOTRACK flag to stop using it.

Link: http://lkml.kernel.org/r/20171007030159.22241-3-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Hansen <devtimhansen@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-15 18:21:04 -08:00
David Howells e462ec50cb VFS: Differentiate mount flags (MS_*) from internal superblock flags
Differentiate the MS_* flags passed to mount(2) from the internal flags set
in the super_block's s_flags.  s_flags are now called SB_*, with the names
and the values for the moment mirroring the MS_* flags that they're
equivalent to.

In this patch, just the headers are altered and some kernel code where
blind automated conversion isn't necessarily correct.

Note that this shows up some interesting issues:

 (1) Some MS_* flags get translated to MNT_* flags (such as MS_NODEV ->
     MNT_NODEV) without passing this on to the filesystem, but some
     filesystems set such flags anyway.

 (2) The ->remount_fs() methods of some filesystems adjust the *flags
     argument by setting MS_* flags in it, such as MS_NOATIME - but these
     flags are then scrubbed by do_remount_sb() (only the occupants of
     MS_RMT_MASK are permitted: MS_RDONLY, MS_SYNCHRONOUS, MS_MANDLOCK,
     MS_I_VERSION and MS_LAZYTIME)

I'm not sure what's the best way to solve all these cases.

Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
2017-07-17 08:45:35 +01:00
David Howells bc98a42c1f VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)
Firstly by applying the following with coccinelle's spatch:

	@@ expression SB; @@
	-SB->s_flags & MS_RDONLY
	+sb_rdonly(SB)

to effect the conversion to sb_rdonly(sb), then by applying:

	@@ expression A, SB; @@
	(
	-(!sb_rdonly(SB)) && A
	+!sb_rdonly(SB) && A
	|
	-A != (sb_rdonly(SB))
	+A != sb_rdonly(SB)
	|
	-A == (sb_rdonly(SB))
	+A == sb_rdonly(SB)
	|
	-!(sb_rdonly(SB))
	+!sb_rdonly(SB)
	|
	-A && (sb_rdonly(SB))
	+A && sb_rdonly(SB)
	|
	-A || (sb_rdonly(SB))
	+A || sb_rdonly(SB)
	|
	-(sb_rdonly(SB)) != A
	+sb_rdonly(SB) != A
	|
	-(sb_rdonly(SB)) == A
	+sb_rdonly(SB) == A
	|
	-(sb_rdonly(SB)) && A
	+sb_rdonly(SB) && A
	|
	-(sb_rdonly(SB)) || A
	+sb_rdonly(SB) || A
	)

	@@ expression A, B, SB; @@
	(
	-(sb_rdonly(SB)) ? 1 : 0
	+sb_rdonly(SB)
	|
	-(sb_rdonly(SB)) ? A : B
	+sb_rdonly(SB) ? A : B
	)

to remove left over excess bracketage and finally by applying:

	@@ expression A, SB; @@
	(
	-(A & MS_RDONLY) != sb_rdonly(SB)
	+(bool)(A & MS_RDONLY) != sb_rdonly(SB)
	|
	-(A & MS_RDONLY) == sb_rdonly(SB)
	+(bool)(A & MS_RDONLY) == sb_rdonly(SB)
	)

to make comparisons against the result of sb_rdonly() (which is a bool)
work correctly.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-07-17 08:45:34 +01:00
Jungseung Lee 39a0e975c3 init: reduce rootwait polling interval time to 5ms
For several devices, the rootwait time is sensitive because it directly
affects booting time.  The polling interval of rootwait is currently
100ms.  To save unnessesary waiting time, reduce the polling interval to
5 ms.

[akpm@linux-foundation.org: remove used-once #define]
Link: http://lkml.kernel.org/r/20161207060743.1728-1-js07.lee@samsung.com
Signed-off-by: Jungseung Lee <js07.lee@samsung.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12 18:55:10 -08:00
Vishnu Pratap Singh c69e3c3a0c init/do_mounts.c: add create_dev() failure log
If create_dev() function fails to create the root mount device
(/dev/root), then it goes to panic as root device not found but there is
no printk in this case.  So I have added the log in case it fails to
create the root device.  It will help in debugging.

[akpm@linux-foundation.org: simplify printk(), use pr_emerg(), display errno]
Signed-off-by: Vishnu Pratap Singh <vishnu.ps@samsung.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Dan Ehrenberg <dehrenberg@chromium.org>
Cc: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-25 17:00:42 -07:00
Chen Yu cb31ef485d init: fix regression by supporting devices with major:minor:offset format
Commit 283e7ad02 ("init: stricter checking of major:minor root=
values") was so strict that it exposed the fact that a previously
unknown device format was being used.

Distributions like Ubuntu uses klibc (rather than uswsusp) to resume
system from hibernation.  klibc expressed the swap partition/file in
the form of major:minor:offset.  For example, 8:3:0 represents a swap
partition in klibc, and klibc's resume process in initrd will finally
echo 8:3:0 to /sys/power/resume for manually resuming.  However, due
to commit 283e7ad02's stricter checking, 8:3:0 will be treated as an
invalid device format, and manual resuming from hibernation will fail.

Fix this by adding support for devices with major:minor:offset format
when resuming from hibernation.

Reported-by: Prigent, Christophe <christophe.prigent@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-05-05 12:31:37 -04:00
Dan Ehrenberg 283e7ad024 init: stricter checking of major:minor root= values
In the kernel command-line, previously, root=1:2jakshflaksjdhfa would
be accepted and interpreted just like root=1:2. This patch adds
stricter checking so that additional characters after major:minor are
rejected by root=.

The goal of this change is to help in unifying DM's interpretation of
its block device argument by using existing kernel code (name_to_dev_t).
But DM rejects malformed major:minor pairs, it seems reasonable for
root= to reject them as well.

Signed-off-by: Dan Ehrenberg <dehrenberg@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-04-15 12:10:19 -04:00
Dan Ehrenberg e6e20a7a5f init: export name_to_dev_t and mark name argument as const
DM will switch its device lookup code to using name_to_dev_t() so it
must be exported.  Also, the @name argument should be marked const.

Signed-off-by: Dan Ehrenberg <dehrenberg@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-04-15 12:10:18 -04:00