[tree-wide] finally take no_llseek out

no_llseek had been defined to NULL two years ago, in commit 868941b14441
("fs: remove no_llseek")

To quote that commit,

At -rc1 we'll need do a mechanical

[tree-wide] finally take no_llseek out

no_llseek had been defined to NULL two years ago, in commit 868941b14441
("fs: remove no_llseek")

To quote that commit,

At -rc1 we'll need do a mechanical removal of no_llseek -

git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done

would do it.

Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.

Signed-off-by: Al Viro <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

fuse: remove unneeded lock which protecting update of congestion_threshold

Commit 670d21c6e17f6 ("fuse: remove reliance on bdi congestion") change how
congestion_threshold is used and lock in
fuse_c

fuse: remove unneeded lock which protecting update of congestion_threshold

Commit 670d21c6e17f6 ("fuse: remove reliance on bdi congestion") change how
congestion_threshold is used and lock in
fuse_conn_congestion_threshold_write is not needed anymore.
1. Access to supe_block is removed along with removing of bdi congestion.
Then down_read(&fc->killsb) which protecting access to super_block is no
needed.
2. Compare num_background and congestion_threshold without holding
bg_lock. Then there is no need to hold bg_lock to update
congestion_threshold.

Signed-off-by: Kemeng Shi <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>

show more ...

fuse: convert to new timestamp accessors

Convert to using the new inode timestamp accessor functions.

Signed-off-by: Jeff Layton <[email protected]>
Link: https://lore.kernel.org/r/20231004185347.

fuse: convert to new timestamp accessors

Convert to using the new inode timestamp accessor functions.

Signed-off-by: Jeff Layton <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

show more ...

fuse: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

fuse: convert to ctime accessor functions

In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Signed-off-by: Jeff Layton <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Christian Brauner <[email protected]>

show more ...

fuse: Remove the control interface for virtio-fs

The commit 15c8e72e88e0 ("fuse: allow skipping control interface and forced
unmount") tries to remove the control interface for virtio-fs since it do

fuse: Remove the control interface for virtio-fs

The commit 15c8e72e88e0 ("fuse: allow skipping control interface and forced
unmount") tries to remove the control interface for virtio-fs since it does
not support aborting requests which are being processed. But it doesn't
work now.

This patch fixes it by skipping creating the control interface if
fuse_conn->no_control is set.

Fixes: 15c8e72e88e0 ("fuse: allow skipping control interface and forced unmount")
Signed-off-by: Xie Yongji <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>

show more ...

fuse: remove reliance on bdi congestion

The bdi congestion tracking in not widely used and will be removed.

Fuse is one of a small number of filesystems that uses it, setting both
the sync (read) a

fuse: remove reliance on bdi congestion

The bdi congestion tracking in not widely used and will be removed.

Fuse is one of a small number of filesystems that uses it, setting both
the sync (read) and async (write) congestion flags at what it determines
are appropriate times.

The only remaining effect of the sync flag is to cause read-ahead to be
skipped. The only remaining effect of the async flag is to cause (some)
WB_SYNC_NONE writes to be skipped.

So instead of setting the flags, change:

- .readahead to stop when it has submitted all non-async pages for
read.

- .writepages to do nothing if WB_SYNC_NONE and the flag would be set

- .writepage to return AOP_WRITEPAGE_ACTIVATE if WB_SYNC_NONE and the
flag would be set.

The writepages change causes a behavioural change in that pageout() can
now return PAGE_ACTIVATE instead of PAGE_KEEP, so SetPageActive() will be
called on the page which (I think) will further delay the next attempt at
writeout. This might be a good thing.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: NeilBrown <[email protected]>
Cc: Anna Schumaker <[email protected]>
Cc: Chao Yu <[email protected]>
Cc: Darrick J. Wong <[email protected]>
Cc: Ilya Dryomov <[email protected]>
Cc: Jaegeuk Kim <[email protected]>
Cc: Jan Kara <[email protected]>
Cc: Jeff Layton <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Lars Ellenberg <[email protected]>
Cc: Miklos Szeredi <[email protected]>
Cc: Paolo Valente <[email protected]>
Cc: Philipp Reisner <[email protected]>
Cc: Ryusuke Konishi <[email protected]>
Cc: Trond Myklebust <[email protected]>
Cc: Wu Fengguang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

fuse: name fs_context consistently

Naming convention under fs/fuse/:

struct fuse_conn *fc;
struct fs_context *fsc;

Signed-off-by: Miklos Szeredi <[email protected]>

fuse: split fuse_mount off of fuse_conn

We want to allow submounts for the same fuse_conn, but with different
superblocks so that each of the submounts has its own device ID. To do
so, we need to s

fuse: split fuse_mount off of fuse_conn

We want to allow submounts for the same fuse_conn, but with different
superblocks so that each of the submounts has its own device ID. To do
so, we need to split all mount-specific information off of fuse_conn
into a new fuse_mount structure, so that multiple mounts can share a
single fuse_conn.

We need to take care only to perform connection-level actions once (i.e.
when the fuse_conn and thus the first fuse_mount are established, or
when the last fuse_mount and thus the fuse_conn are destroyed). For
example, fuse_sb_destroy() must invoke fuse_send_destroy() until the
last superblock is released.

To do so, we keep track of which fuse_mount is the root mount and
perform all fuse_conn-level actions only when this fuse_mount is
involved.

Signed-off-by: Max Reitz <[email protected]>
Reviewed-by: Stefan Hajnoczi <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>

show more ...

treewide: Remove uninitialized_var() usage

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused vari

treewide: Remove uninitialized_var() usage

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
xargs perl -pi -e \
's/\buninitialized_var\(([^\)]+)\)/\1/g;
s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/[email protected]/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <[email protected]> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <[email protected]> # IB
Acked-by: Kalle Valo <[email protected]> # wireless drivers
Reviewed-by: Chao Yu <[email protected]> # erofs
Signed-off-by: Kees Cook <[email protected]>

show more ...

convenience helper: get_tree_single()

counterpart of mount_single(); switch fusectl to it

Signed-off-by: Al Viro <[email protected]>

fuse: Convert fusectl to use the new mount API

Convert the fusectl filesystem to the new internal mount API as the old
one will be obsoleted and removed. This allows greater flexibility in
communic

fuse: Convert fusectl to use the new mount API

Convert the fusectl filesystem 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.

Signed-off-by: David Howells <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>

show more ...

fuse: clean up aborted

The only caller that needs fc->aborted set is fuse_conn_abort_write().
Setting fc->aborted is now racy (fuse_abort_conn() may already be in
progress or finished) but there's n

fuse: clean up aborted

The only caller that needs fc->aborted set is fuse_conn_abort_write().
Setting fc->aborted is now racy (fuse_abort_conn() may already be in
progress or finished) but there's no reason to care.

Signed-off-by: Miklos Szeredi <[email protected]>

show more ...

fuse: introduce fc->bg_lock

To reduce contention of fc->lock, this patch introduces bg_lock for
protection of fields related to background queue. These are:
max_background, congestion_threshold, num

fuse: introduce fc->bg_lock

To reduce contention of fc->lock, this patch introduces bg_lock for
protection of fields related to background queue. These are:
max_background, congestion_threshold, num_background, active_background,
bg_queue and blocked.

This allows next patch to make async reads not requiring fc->lock, so async
reads and writes will have better performance executed in parallel.

Signed-off-by: Kirill Tkhai <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>

show more ...

fuse: add locking to max_background and congestion_threshold changes

Functions sequences like request_end()->flush_bg_queue() require that
max_background and congestion_threshold are constant during

fuse: add locking to max_background and congestion_threshold changes

Functions sequences like request_end()->flush_bg_queue() require that
max_background and congestion_threshold are constant during their
execution. Otherwise, checks like

if (fc->num_background == fc->max_background)

made in different time may behave not like expected.

Signed-off-by: Kirill Tkhai <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>

show more ...

fuse: use READ_ONCE on congestion_threshold and max_background

Since they are of unsigned int type, it's allowed to read them
unlocked during reporting to userspace. Let's underline this fact
with R

fuse: use READ_ONCE on congestion_threshold and max_background

Since they are of unsigned int type, it's allowed to read them
unlocked during reporting to userspace. Let's underline this fact
with READ_ONCE() macroses.

Signed-off-by: Kirill Tkhai <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>

show more ...

fuse: fix control dir setup and teardown

syzbot is reporting NULL pointer dereference at fuse_ctl_remove_conn() [1].
Since fc->ctl_ndents is incremented by fuse_ctl_add_conn() when new_inode()
faile

fuse: fix control dir setup and teardown

syzbot is reporting NULL pointer dereference at fuse_ctl_remove_conn() [1].
Since fc->ctl_ndents is incremented by fuse_ctl_add_conn() when new_inode()
failed, fuse_ctl_remove_conn() reaches an inode-less dentry and tries to
clear d_inode(dentry)->i_private field.

Fix by only adding the dentry to the array after being fully set up.

When tearing down the control directory, do d_invalidate() on it to get rid
of any mounts that might have been added.

[1] https://syzkaller.appspot.com/bug?id=f396d863067238959c91c0b7cfc10b163638cac6
Reported-by: syzbot <[email protected]>
Fixes: bafa96541b25 ("[PATCH] fuse: add control filesystem")
Cc: <[email protected]> # v2.6.18
Signed-off-by: Miklos Szeredi <[email protected]>

show more ...

fuse: return -ECONNABORTED on /dev/fuse read after abort

Currently the userspace has no way of knowing whether the fuse
connection ended because of umount or abort via sysfs. It makes it hard
for fi

fuse: return -ECONNABORTED on /dev/fuse read after abort

Currently the userspace has no way of knowing whether the fuse
connection ended because of umount or abort via sysfs. It makes it hard
for filesystems to free the mountpoint after abort without worrying
about removing some new mount.

The patch fixes it by returning different errors when userspace reads
from /dev/fuse (-ENODEV for umount and -ECONNABORTED for abort).

Add a new capability flag FUSE_ABORT_ERROR. If set and the connection is
gone because of sysfs abort, reading from the device will return
-ECONNABORTED.

Signed-off-by: Szymon Lukasz <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>

show more ...

fs: constify tree_descr arrays passed to simple_fill_super()

simple_fill_super() is passed an array of tree_descr structures which
describe the files to create in the filesystem's root directory. S

fs: constify tree_descr arrays passed to simple_fill_super()

simple_fill_super() is passed an array of tree_descr structures which
describe the files to create in the filesystem's root directory. Since
these arrays are never modified intentionally, they should be 'const' so
that they are placed in .rodata and benefit from memory protection.
This patch updates the function signature and all users, and also
constifies tree_descr.name.

Signed-off-by: Eric Biggers <[email protected]>
Signed-off-by: Al Viro <[email protected]>

show more ...

fs: Replace CURRENT_TIME with current_time() for inode timestamps

CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current

fs: Replace CURRENT_TIME with current_time() for inode timestamps

CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_time() instead.

CURRENT_TIME is also not y2038 safe.

This is also in preparation for the patch that transitions
vfs timestamps to use 64 bit time and hence make them
y2038 safe. As part of the effort current_time() will be
extended to do range checks. Hence, it is necessary for all
file system timestamps to use current_time(). Also,
current_time() will be transitioned along with vfs to be
y2038 safe.

Note that whenever a single call to current_time() is used
to change timestamps in different inodes, it is because they
share the same time granularity.

Signed-off-by: Deepa Dinamani <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Acked-by: Felipe Balbi <[email protected]>
Acked-by: Steven Whitehouse <[email protected]>
Acked-by: Ryusuke Konishi <[email protected]>
Acked-by: David Sterba <[email protected]>
Signed-off-by: Al Viro <[email protected]>

show more ...

VFS: normal filesystems (and lustre): d_inode() annotations

that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <[email protected]>
Signed-off-by:

VFS: normal filesystems (and lustre): d_inode() annotations

that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <[email protected]>
Signed-off-by: Al Viro <[email protected]>

show more ...

fuse: add __exit to fuse_ctl_cleanup

fuse_ctl_cleanup is only called by __exit fuse_exit

Signed-off-by: Fabian Frederick <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>

fs: Limit sys_mount to only request filesystem modules.

Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to

fs: Limit sys_mount to only request filesystem modules.

Modify the request_module to prefix the file system type with "fs-"
and add aliases to all of the filesystems that can be built as modules
to match.

A common practice is to build all of the kernel code and leave code
that is not commonly needed as modules, with the result that many
users are exposed to any bug anywhere in the kernel.

Looking for filesystems with a fs- prefix limits the pool of possible
modules that can be loaded by mount to just filesystems trivially
making things safer with no real cost.

Using aliases means user space can control the policy of which
filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf
with blacklist and alias directives. Allowing simple, safe,
well understood work-arounds to known problematic software.

This also addresses a rare but unfortunate problem where the filesystem
name is not the same as it's module name and module auto-loading
would not work. While writing this patch I saw a handful of such
cases. The most significant being autofs that lives in the module
autofs4.

This is relevant to user namespaces because we can reach the request
module in get_fs_type() without having any special permissions, and
people get uncomfortable when a user specified string (in this case
the filesystem type) goes all of the way to request_module.

After having looked at this issue I don't think there is any
particular reason to perform any filtering or permission checks beyond
making it clear in the module request that we want a filesystem
module. The common pattern in the kernel is to call request_module()
without regards to the users permissions. In general all a filesystem
module does once loaded is call register_filesystem() and go to sleep.
Which means there is not much attack surface exposed by loading a
filesytem module unless the filesystem is mounted. In a user
namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT,
which most filesystems do not set today.

Acked-by: Serge Hallyn <[email protected]>
Acked-by: Kees Cook <[email protected]>
Reported-by: Kees Cook <[email protected]>
Signed-off-by: "Eric W. Biederman" <[email protected]>

show more ...

new helper: file_inode(file)

Signed-off-by: Al Viro <[email protected]>

fuse: mark variables uninitialized

gcc 4.6.3 complains about uninitialized variables in fs/fuse/control.c:

CC fs/fuse/control.o
fs/fuse/control.c: In function 'fuse_conn_congestion_threshold

fuse: mark variables uninitialized

gcc 4.6.3 complains about uninitialized variables in fs/fuse/control.c:

CC fs/fuse/control.o
fs/fuse/control.c: In function 'fuse_conn_congestion_threshold_write':
fs/fuse/control.c:165:29: warning: 'val' may be used uninitialized in this function [-Wuninitialized]
fs/fuse/control.c: In function 'fuse_conn_max_background_write':
fs/fuse/control.c:128:23: warning: 'val' may be used uninitialized in this function [-Wuninitialized]

fuse_conn_limit_write() will always return non-zero unless the &val
is modified, so the warning is misleading. Let the compiler know
about it by marking 'val' with 'uninitialized_var'.

Signed-off-by: Daniel Mack <[email protected]>
Cc: Brian Foster <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>

show more ...

fuse: Convert to kstrtoul_from_user

This patch replaces the code for getting an number from a
userspace buffer by a simple call to kstroul_from_user.
This makes it easier to read and less error pron

fuse: Convert to kstrtoul_from_user

This patch replaces the code for getting an number from a
userspace buffer by a simple call to kstroul_from_user.
This makes it easier to read and less error prone.

Signed-off-by: Peter Huewe <[email protected]>
Signed-off-by: Miklos Szeredi <[email protected]>

show more ...