Introduce kernfs interface for finding, getting and putting
sysfs_dirents.
* sysfs_find_dirent() is renamed to kernfs_find_ns() and lockdep
assertion for sysfs_mutex is added.
* sysfs_get_dirent_ns() is renamed to kernfs_find_and_get().
* Macro inline dancing around __sysfs_get/put() are removed and
kernfs_get/put() are made proper functions implemented in
fs/sysfs/dir.c.
While the conversions are mostly equivalent, there's one difference -
kernfs_get() doesn't return the input param as its return value. This
change is intentional. While passing through the input increases
writability in some areas, it is unnecessary and has been shown to
cause confusion regarding how the last ref is handled.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, sysfs_dirent active_ref lockdep annotation uses
attribute->[s]key as the lockdep key, which forces
kernfs_create_file_ns() to assume that sysfs_dirent->priv is pointing
to a struct attribute which may not be true for non-sysfs users. This
patch restructures the lockdep annotation such that
* kernfs_ops contains lockdep_key which is used by default for files
created kernfs_create_file_ns().
* kernfs_create_file_ns_key() is introduced which takes an extra @key
argument. The created file will use the specified key for
active_ref lockdep annotation. If NULL is specified, lockdep for
the file is disabled.
* sysfs_add_file_mode_ns() is updated to use
kernfs_create_file_ns_key() with the appropriate key from the
attribute or NULL if ignore_lockdep is set.
This makes the lockdep annotation properly contained in kernfs while
allowing sysfs to cleanly keep its current behavior. This patch
doesn't introduce any behavior differences.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We want to add one more SYSFS_FLAG_* but we can't use the next higher
bit, 0x10000, as the flag field is 16bits wide. The flags are
currently arranged weirdly - 8 bits are set aside for the type flags
when there are only three three used, the first flag starts at 0x1000
instead of 0x0100 and flag literals have 5 digits (20 bits) when only
4 digits can be used.
Rearrange them so that type bits are only the lowest four, flags start
at 0x0010 and similar flags are grouped.
This patch doesn't cause any behavior difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce kernfs interface to wake up poll(2) which takes and returns
sysfs_dirents.
sysfs_notify_dirent() is renamed to kernfs_notify() and sysfs_notify()
is updated so that it doesn't directly grab sysfs_mutex but acquires
the target sysfs_dirents using sysfs_get_dirent().
sysfs_notify_dirent() is reimplemented as a dumb inline wrapper around
kernfs_notify().
This patch doesn't introduce any behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
kernfs_ops currently only supports single_open() behavior which is
pretty restrictive. Add optional callbacks ->seq_{start|next|stop}()
which, when implemented, are invoked for seq_file traversal. This
allows full seq_file functionality for kernfs users. This currently
doesn't have any user and doesn't change any behavior.
v2: Refreshed on top of the updated "sysfs, kernfs: prepare read path
for kernfs".
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs_add_one() is a wrapper around __sysfs_add_one() which prints out
duplicate name warning if __sysfs_add_one() fails with -EEXIST. The
previous kernfs conversions moved all dup warnings to sysfs interface
functions and sysfs_add_one() doesn't have any user left.
Remove sysfs_add_one() and update __sysfs_add_one() to take its name.
This patch doesn't make any functional changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce kernfs interface to create a file which takes and returns
sysfs_dirents.
The actual file creation part is separated out from
sysfs_add_file_mode_ns() into kernfs_create_file_ns(). The former now
only decides the kernfs_ops to use and the file's size and invokes the
latter.
This patch doesn't introduce behavior changes.
v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
After kernfs_ops and sysfs_dirent->s_attr.size addition, the
distinction between SYSFS_KOBJ_BIN_ATTR and SYSFS_KOBJ_ATTR is only
necessary while creating files to decide which kernfs_ops to use.
Afterwards, they behave exactly the same.
This patch removes SYSFS_KOBJ_BIN_ATTR along with sysfs_is_bin().
sysfs_add_file[_mode_ns]() are updated to take bool @is_bin instead of
@type.
This patch doesn't introduce any behavior changes. This completely
isolates the distinction between the two sysfs file types in the sysfs
layer proper.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs sets the size of regular files unconditionally at PAGE_SIZE and
takes the size of bin files from bin_attribute. The latter is a
pretty bad interface which forces bin_attribute users to create a
separate copy of bin_attribute for each instance of the file -
e.g. pci resource files.
Add sysfs_dirent->s_attr.size so that the size can be specified
separately. This unifies inode init paths of ATTR and BIN_ATTR
identical and allows for generic size handling for kernfs.
Unfortunately, this grows the size of sysfs_dirent by sizeof(loff_t).
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We're in the process of separating out core sysfs functionality into
kernfs which will deal with sysfs_dirents directly. This patch
introduces kernfs_ops which hosts methods kernfs users implement and
updates fs/sysfs/file.c such that sysfs_kf_*() functions populate
kernfs_ops and kernfs_file_*() functions call the matching entries
from kernfs_ops.
kernfs_ops contains the following groups of methods.
* seq_show() - for kernfs files which use seq_file for reads.
* read() - for direct read implementations. Used iff seq_show() is
not implemented.
* write() - for writes.
* mmap() - for mmaps.
Notes:
* sysfs_elem_attr->ops is added so that kernfs_ops can be accessed
from sysfs_dirent. kernfs_ops() helper is added to verify locking
and access the field.
* SYSFS_FLAG_HAS_(SEQ_SHOW|MMAP) added. sd->s_attr->ops is accessible
only while holding active_ref and there are cases where we want to
take different actions depending on which ops are implemented.
These two flags cache whether the two ops are implemented for those.
* kernfs_file_*() no longer test sysfs type but chooses different
behaviors depending on which methods in kernfs_ops are implemented.
The conversions are trivial except for the open path. As
kernfs_file_open() now decides whether to allow read/write accesses
depending on the kernfs_ops implemented, the presence of methods in
kobjs and attribute_bin should be propagated to kernfs_ops.
sysfs_add_file_mode_ns() is updated so that it propagates presence /
absence of the callbacks through _empty, _ro, _wo, _rw kernfs_ops.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs_open_file will be used as the primary handle for kernfs methods.
Move its definition from fs/sysfs/file.c to include/linux/kernfs.h and
mark the public and private fields.
This is pure relocation.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We're in the process of separating out core sysfs functionality into
kernfs which will deal with sysfs_dirents directly. This patch
prepares the rest - open, release and poll. There isn't much to do.
Just renaming is enough. As sysfs_file_operations and
sysfs_bin_operations are identical now, use the same file_operations
for both - kernfs_file_operations.
This patch doesn't introduce any behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We're in the process of separating out core sysfs functionality into
kernfs which will deal with sysfs_dirents directly. This patch
rearranges mmap path so that the kernfs and sysfs parts are separate.
sysfs_kf_bin_mmap() which handles the interaction with bin_attribute
mmap method is factored out of sysfs_bin_mmap(), which is renamed to
kernfs_file_mmap(). All vma ops are renamed accordingly.
sysfs_bin_mmap() is updated such that it can be used for both file
types. This will eventually allow using the same file_operations for
both file types, which is necessary to separate out kernfs.
This patch doesn't introduce any behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We're in the process of separating out core sysfs functionality into
kernfs which will deal with sysfs_dirents directly. This patch
rearranges write path so that the kernfs and sysfs parts are separate.
kernfs_file_write() handles all boilerplate work including buffer
management and locking and invokes sysfs_kf_write() or
sysfs_kf_bin_write() depending on the file type which deals with the
interaction with kobj store or bin_attribute write method.
While this patch changes the order of some operations, it shouldn't
change any visible behavior.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We're in the process of separating out core sysfs functionality into
kernfs which will deal with sysfs_dirents directly. This patch
rearranges read path so that the kernfs and sysfs parts are separate.
* Regular file read path is refactored such that
kernfs_seq_start/next/stop/show() handle all the boilerplate work
including locking and updating event count for poll, while
sysfs_kf_seq_show() deals with interaction with kobj show method.
* Bin file read path is refactored such that kernfs_file_direct_read()
handles all the boilerplate work including buffer management and
locking, while sysfs_kf_bin_read() deals with interaction with
bin_attribute read method.
kernfs_file_read() is added. It invokes either the seq_file or direct
read path depending on the file type. This will eventually allow
using the same file_operations for both file types, which is necessary
to separate out kernfs.
While this patch changes the order of some operations, it shouldn't
change any visible behavior.
v2: Dropped unnecessary zeroing of @count from sysfs_kf_seq_show().
Add comments explaining single_open() behavior. Both suggested by
Pavel.
v3: seq_stop() is called even after seq_start() failed.
kernfs_seq_start() updated so that it doesn't unlock
sysfs_open_file->mutex on failure so that kernfs_seq_stop()
doesn't try to unlock an already unlocked mutex. Reported by
Fengguang.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduce kernfs interface to manipulate a directory which takes and
returns sysfs_dirents.
create_dir() is renamed to kernfs_create_dir_ns() and its argumantes
and return value are updated. create_dir() usages are replaced with
kernfs_create_dir_ns() and sysfs_create_subdir() usages are replaced
with kernfs_create_dir(). Dup warnings are handled explicitly by
sysfs users of the kernfs interface.
sysfs_enable_ns() is renamed to kernfs_enable_ns().
This patch doesn't introduce any behavior changes.
v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS.
v3: kernfs_enable_ns() added.
v4: Refreshed on top of "sysfs: drop kobj_ns_type handling, take #2"
so that this patch removes sysfs_enable_ns().
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A directory sysfs_dirent points to the associated kobj. A regular or
bin file points to the associated [bin_]attribute. This patch
replaces sysfs_dirent->s_dir.kobj and ->s_attr.[bin_]attr with void *
->priv.
This is to prepare for kernfs interface so that sysfs can specify the
private data in the same way for directories and files. This lower
debuggability but not by much - the whole thing was overlaid in a
union anyway. If debuggability becomes an issue, we can later add
->priv accessors which explicitly check for the sysfs_dirent type and
performs casting.
This patch doesn't introduce any behavior difference.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull vfs dentry reference count fix from Al Viro.
This fixes a possible inode_permission NULL pointer dereference (and
other problems) that were due to the root dentry count being decremented
too much. In commit 48a066e72d ("RCU'd vfsmounts") the placement of
clearing the LOOKUP_RCU bit changed, and we then returned failure of
incrementing the lockref on the parent dentry with LOOKUP_RCU cleared.
But that meant we needed to go through the same cleanup routines that
the later failures did wrt LOOKUP_ROOT and nd->root.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fix bogus path_put() of nd->root after some unlazy_walk() failures
Failure to grab reference to parent dentry should go through the
same cleanup as nd->seq mismatch. As it is, we might end up with
caller thinking it needs to path_put() nd->root, with obvious
nasty results once we'd hit that bug enough times to drive the
refcount of root dentry all the way to zero...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull cifs fixes from Steve French:
"SMB3 "validate negotiate" is needed to prevent certain types of
downgrade attacks.
Also changes SMB2/SMB3 copy offload from using the BTRFS copy ioctl
(BTRFS_IOC_CLONE) to a cifs specific ioctl (CIFS_IOC_COPYCHUNK_FILE)
to address Christoph's comment that there are semantic differences
between requesting copy offload in which copy-on-write is mandatory
(as in the BTRFS ioctl) and optional in the SMB2/SMB3 case. Also
fixes SMB2/SMB3 copychunk for large files"
* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
[CIFS] Do not use btrfs refcopy ioctl for SMB2 copy offload
Check SMB3 dialects against downgrade attacks
Removed duplicated (and unneeded) goto
CIFS: Fix SMB2/SMB3 Copy offload support (refcopy) for large files
We need those sysfs fixes in this branch to make testing, and future
patches apply properly.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull driver core fixes from Greg KH:
"Here are 3 patches for sysfs issues that have been reported. Well, 1
patch really, the first one is reverted as it's not really needed (the
correct fix is coming in through the different driver subsystems
instead)
But that 1 sysfs fix is needed, so this is still a good thing to pull
in now"
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* tag 'driver-core-3.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
Revert "sysfs: handle duplicate removal attempts in sysfs_remove_group()"
sysfs: use a separate locking class for open files depending on mmap
sysfs: handle duplicate removal attempts in sysfs_remove_group()
This tool hasn't been maintained in over a decade, and is pretty much
useless these days. Let's pretend it never happened.
Also remove a long-dead email address.
Signed-off-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce kernfs setattr interface - kernfs_setattr().
sysfs_sd_setattr() is renamed to __kernfs_setattr() and
kernfs_setattr() is a simple wrapper around it with sysfs_mutex
locking. sysfs_chmod_file() is updated to get an explicit ref on
kobj->sd and then invoke kernfs_setattr() so that it doesn't have to
use internal interface.
This patch doesn't introduce any behavior differences.
v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tejun Heo
Greg Kroah-Hartman
Linus Torvalds
Al Viro
Dave Jones