Commit Graph

248 Commits

Author SHA1 Message Date
Guenter Roeck 1823342a1f configfs: replace strncpy with memcpy
gcc 8.1.0 complains:

fs/configfs/symlink.c:67:3: warning:
	'strncpy' output truncated before terminating nul copying as many
	bytes from a string as its length
fs/configfs/symlink.c: In function 'configfs_get_link':
fs/configfs/symlink.c:63:13: note: length computed here

Using strncpy() is indeed less than perfect since the length of data to
be copied has already been determined with strlen(). Replace strncpy()
with memcpy() to address the warning and optimize the code a little.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-07-02 07:12:55 -06:00
Bart Van Assche 707c623529 configfs: use kvasprintf() instead of open-coding it
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-06-19 07:08:12 +02:00
Deepa Dinamani 95582b0083 vfs: change inode times to use struct timespec64
struct timespec is not y2038 safe. Transition vfs to use
y2038 safe struct timespec64 instead.

The change was made with the help of the following cocinelle
script. This catches about 80% of the changes.
All the header file and logic changes are included in the
first 5 rules. The rest are trivial substitutions.
I avoid changing any of the function signatures or any other
filesystem specific data structures to keep the patch simple
for review.

The script can be a little shorter by combining different cases.
But, this version was sufficient for my usecase.

virtual patch

@ depends on patch @
identifier now;
@@
- struct timespec
+ struct timespec64
  current_time ( ... )
  {
- struct timespec now = current_kernel_time();
+ struct timespec64 now = current_kernel_time64();
  ...
- return timespec_trunc(
+ return timespec64_trunc(
  ... );
  }

@ depends on patch @
identifier xtime;
@@
 struct \( iattr \| inode \| kstat \) {
 ...
-       struct timespec xtime;
+       struct timespec64 xtime;
 ...
 }

@ depends on patch @
identifier t;
@@
 struct inode_operations {
 ...
int (*update_time) (...,
-       struct timespec t,
+       struct timespec64 t,
...);
 ...
 }

@ depends on patch @
identifier t;
identifier fn_update_time =~ "update_time$";
@@
 fn_update_time (...,
- struct timespec *t,
+ struct timespec64 *t,
 ...) { ... }

@ depends on patch @
identifier t;
@@
lease_get_mtime( ... ,
- struct timespec *t
+ struct timespec64 *t
  ) { ... }

@te depends on patch forall@
identifier ts;
local idexpression struct inode *inode_node;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
identifier fn_update_time =~ "update_time$";
identifier fn;
expression e, E3;
local idexpression struct inode *node1;
local idexpression struct inode *node2;
local idexpression struct iattr *attr1;
local idexpression struct iattr *attr2;
local idexpression struct iattr attr;
identifier i_xtime1 =~ "^i_[acm]time$";
identifier i_xtime2 =~ "^i_[acm]time$";
identifier ia_xtime1 =~ "^ia_[acm]time$";
identifier ia_xtime2 =~ "^ia_[acm]time$";
@@
(
(
- struct timespec ts;
+ struct timespec64 ts;
|
- struct timespec ts = current_time(inode_node);
+ struct timespec64 ts = current_time(inode_node);
)

<+... when != ts
(
- timespec_equal(&inode_node->i_xtime, &ts)
+ timespec64_equal(&inode_node->i_xtime, &ts)
|
- timespec_equal(&ts, &inode_node->i_xtime)
+ timespec64_equal(&ts, &inode_node->i_xtime)
|
- timespec_compare(&inode_node->i_xtime, &ts)
+ timespec64_compare(&inode_node->i_xtime, &ts)
|
- timespec_compare(&ts, &inode_node->i_xtime)
+ timespec64_compare(&ts, &inode_node->i_xtime)
|
ts = current_time(e)
|
fn_update_time(..., &ts,...)
|
inode_node->i_xtime = ts
|
node1->i_xtime = ts
|
ts = inode_node->i_xtime
|
<+... attr1->ia_xtime ...+> = ts
|
ts = attr1->ia_xtime
|
ts.tv_sec
|
ts.tv_nsec
|
btrfs_set_stack_timespec_sec(..., ts.tv_sec)
|
btrfs_set_stack_timespec_nsec(..., ts.tv_nsec)
|
- ts = timespec64_to_timespec(
+ ts =
...
-)
|
- ts = ktime_to_timespec(
+ ts = ktime_to_timespec64(
...)
|
- ts = E3
+ ts = timespec_to_timespec64(E3)
|
- ktime_get_real_ts(&ts)
+ ktime_get_real_ts64(&ts)
|
fn(...,
- ts
+ timespec64_to_timespec(ts)
,...)
)
...+>
(
<... when != ts
- return ts;
+ return timespec64_to_timespec(ts);
...>
)
|
- timespec_equal(&node1->i_xtime1, &node2->i_xtime2)
+ timespec64_equal(&node1->i_xtime2, &node2->i_xtime2)
|
- timespec_equal(&node1->i_xtime1, &attr2->ia_xtime2)
+ timespec64_equal(&node1->i_xtime2, &attr2->ia_xtime2)
|
- timespec_compare(&node1->i_xtime1, &node2->i_xtime2)
+ timespec64_compare(&node1->i_xtime1, &node2->i_xtime2)
|
node1->i_xtime1 =
- timespec_trunc(attr1->ia_xtime1,
+ timespec64_trunc(attr1->ia_xtime1,
...)
|
- attr1->ia_xtime1 = timespec_trunc(attr2->ia_xtime2,
+ attr1->ia_xtime1 =  timespec64_trunc(attr2->ia_xtime2,
...)
|
- ktime_get_real_ts(&attr1->ia_xtime1)
+ ktime_get_real_ts64(&attr1->ia_xtime1)
|
- ktime_get_real_ts(&attr.ia_xtime1)
+ ktime_get_real_ts64(&attr.ia_xtime1)
)

@ depends on patch @
struct inode *node;
struct iattr *attr;
identifier fn;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
expression e;
@@
(
- fn(node->i_xtime);
+ fn(timespec64_to_timespec(node->i_xtime));
|
 fn(...,
- node->i_xtime);
+ timespec64_to_timespec(node->i_xtime));
|
- e = fn(attr->ia_xtime);
+ e = fn(timespec64_to_timespec(attr->ia_xtime));
)

@ depends on patch forall @
struct inode *node;
struct iattr *attr;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
identifier fn;
@@
{
+ struct timespec ts;
<+...
(
+ ts = timespec64_to_timespec(node->i_xtime);
fn (...,
- &node->i_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
fn (...,
- &attr->ia_xtime,
+ &ts,
...);
)
...+>
}

@ depends on patch forall @
struct inode *node;
struct iattr *attr;
struct kstat *stat;
identifier ia_xtime =~ "^ia_[acm]time$";
identifier i_xtime =~ "^i_[acm]time$";
identifier xtime =~ "^[acm]time$";
identifier fn, ret;
@@
{
+ struct timespec ts;
<+...
(
+ ts = timespec64_to_timespec(node->i_xtime);
ret = fn (...,
- &node->i_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(node->i_xtime);
ret = fn (...,
- &node->i_xtime);
+ &ts);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
ret = fn (...,
- &attr->ia_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
ret = fn (...,
- &attr->ia_xtime);
+ &ts);
|
+ ts = timespec64_to_timespec(stat->xtime);
ret = fn (...,
- &stat->xtime);
+ &ts);
)
...+>
}

@ depends on patch @
struct inode *node;
struct inode *node2;
identifier i_xtime1 =~ "^i_[acm]time$";
identifier i_xtime2 =~ "^i_[acm]time$";
identifier i_xtime3 =~ "^i_[acm]time$";
struct iattr *attrp;
struct iattr *attrp2;
struct iattr attr ;
identifier ia_xtime1 =~ "^ia_[acm]time$";
identifier ia_xtime2 =~ "^ia_[acm]time$";
struct kstat *stat;
struct kstat stat1;
struct timespec64 ts;
identifier xtime =~ "^[acmb]time$";
expression e;
@@
(
( node->i_xtime2 \| attrp->ia_xtime2 \| attr.ia_xtime2 \) = node->i_xtime1  ;
|
 node->i_xtime2 = \( node2->i_xtime1 \| timespec64_trunc(...) \);
|
 node->i_xtime2 = node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \);
|
 node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \);
|
 stat->xtime = node2->i_xtime1;
|
 stat1.xtime = node2->i_xtime1;
|
( node->i_xtime2 \| attrp->ia_xtime2 \) = attrp->ia_xtime1  ;
|
( attrp->ia_xtime1 \| attr.ia_xtime1 \) = attrp2->ia_xtime2;
|
- e = node->i_xtime1;
+ e = timespec64_to_timespec( node->i_xtime1 );
|
- e = attrp->ia_xtime1;
+ e = timespec64_to_timespec( attrp->ia_xtime1 );
|
node->i_xtime1 = current_time(...);
|
 node->i_xtime2 = node->i_xtime1 = node->i_xtime3 =
- e;
+ timespec_to_timespec64(e);
|
 node->i_xtime1 = node->i_xtime3 =
- e;
+ timespec_to_timespec64(e);
|
- node->i_xtime1 = e;
+ node->i_xtime1 = timespec_to_timespec64(e);
)

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: <anton@tuxera.com>
Cc: <balbi@kernel.org>
Cc: <bfields@fieldses.org>
Cc: <darrick.wong@oracle.com>
Cc: <dhowells@redhat.com>
Cc: <dsterba@suse.com>
Cc: <dwmw2@infradead.org>
Cc: <hch@lst.de>
Cc: <hirofumi@mail.parknet.co.jp>
Cc: <hubcap@omnibond.com>
Cc: <jack@suse.com>
Cc: <jaegeuk@kernel.org>
Cc: <jaharkes@cs.cmu.edu>
Cc: <jslaby@suse.com>
Cc: <keescook@chromium.org>
Cc: <mark@fasheh.com>
Cc: <miklos@szeredi.hu>
Cc: <nico@linaro.org>
Cc: <reiserfs-devel@vger.kernel.org>
Cc: <richard@nod.at>
Cc: <sage@redhat.com>
Cc: <sfrench@samba.org>
Cc: <swhiteho@redhat.com>
Cc: <tj@kernel.org>
Cc: <trond.myklebust@primarydata.com>
Cc: <tytso@mit.edu>
Cc: <viro@zeniv.linux.org.uk>
2018-06-05 16:57:31 -07:00
Bhumika Goyal aa293583f0 configfs: make ci_type field, some pointers and function arguments const
The ci_type field of the config_item structure do not modify the fields
of the config_item_type structure it points to. And the other pointers
initialized with ci_type do not modify the fields as well.
So, make the ci_type field and the pointers initialized with ci_type
as const.

Make the struct config_item_type *type function argument of functions
config_{item/group}_init_type_name const as the argument in both the
functions is only stored in the ci_type field of a config_item structure
which is now made const.
Make the argument of configfs_register_default_group const as it is
only passed to the argument of the function config_group_init_type_name
which is now const.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-19 16:15:16 +02:00
Thomas Meyer 3f6928c347 configfs: Fix bool initialization/comparison
Bool initializations should use true and false. Bool tests don't need
comparisons.

Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-10-19 16:15:14 +02:00
Bart Van Assche 19e72d3abb configfs: Introduce config_item_get_unless_zero()
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
[hch: minor style tweak]
Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-06-12 13:20:20 +02:00
Nicholas Bellinger ba80aa909c configfs: Fix race between create_link and configfs_rmdir
This patch closes a long standing race in configfs between
the creation of a new symlink in create_link(), while the
symlink target's config_item is being concurrently removed
via configfs_rmdir().

This can happen because the symlink target's reference
is obtained by config_item_get() in create_link() before
the CONFIGFS_USET_DROPPING bit set by configfs_detach_prep()
during configfs_rmdir() shutdown is actually checked..

This originally manifested itself on ppc64 on v4.8.y under
heavy load using ibmvscsi target ports with Novalink API:

[ 7877.289863] rpadlpar_io: slot U8247.22L.212A91A-V1-C8 added
[ 7879.893760] ------------[ cut here ]------------
[ 7879.893768] WARNING: CPU: 15 PID: 17585 at ./include/linux/kref.h:46 config_item_get+0x7c/0x90 [configfs]
[ 7879.893811] CPU: 15 PID: 17585 Comm: targetcli Tainted: G           O 4.8.17-customv2.22 #12
[ 7879.893812] task: c00000018a0d3400 task.stack: c0000001f3b40000
[ 7879.893813] NIP: d000000002c664ec LR: d000000002c60980 CTR: c000000000b70870
[ 7879.893814] REGS: c0000001f3b43810 TRAP: 0700   Tainted: G O     (4.8.17-customv2.22)
[ 7879.893815] MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 28222242  XER: 00000000
[ 7879.893820] CFAR: d000000002c664bc SOFTE: 1
                GPR00: d000000002c60980 c0000001f3b43a90 d000000002c70908 c0000000fbc06820
                GPR04: c0000001ef1bd900 0000000000000004 0000000000000001 0000000000000000
                GPR08: 0000000000000000 0000000000000001 d000000002c69560 d000000002c66d80
                GPR12: c000000000b70870 c00000000e798700 c0000001f3b43ca0 c0000001d4949d40
                GPR16: c00000014637e1c0 0000000000000000 0000000000000000 c0000000f2392940
                GPR20: c0000001f3b43b98 0000000000000041 0000000000600000 0000000000000000
                GPR24: fffffffffffff000 0000000000000000 d000000002c60be0 c0000001f1dac490
                GPR28: 0000000000000004 0000000000000000 c0000001ef1bd900 c0000000f2392940
[ 7879.893839] NIP [d000000002c664ec] config_item_get+0x7c/0x90 [configfs]
[ 7879.893841] LR [d000000002c60980] check_perm+0x80/0x2e0 [configfs]
[ 7879.893842] Call Trace:
[ 7879.893844] [c0000001f3b43ac0] [d000000002c60980] check_perm+0x80/0x2e0 [configfs]
[ 7879.893847] [c0000001f3b43b10] [c000000000329770] do_dentry_open+0x2c0/0x460
[ 7879.893849] [c0000001f3b43b70] [c000000000344480] path_openat+0x210/0x1490
[ 7879.893851] [c0000001f3b43c80] [c00000000034708c] do_filp_open+0xfc/0x170
[ 7879.893853] [c0000001f3b43db0] [c00000000032b5bc] do_sys_open+0x1cc/0x390
[ 7879.893856] [c0000001f3b43e30] [c000000000009584] system_call+0x38/0xec
[ 7879.893856] Instruction dump:
[ 7879.893858] 409d0014 38210030 e8010010 7c0803a6 4e800020 3d220000 e94981e0 892a0000
[ 7879.893861] 2f890000 409effe0 39200001 992a0000 <0fe00000> 4bffffd0 60000000 60000000
[ 7879.893866] ---[ end trace 14078f0b3b5ad0aa ]---

To close this race, go ahead and obtain the symlink's target
config_item reference only after the existing CONFIGFS_USET_DROPPING
check succeeds.

This way, if configfs_rmdir() wins create_link() will return -ENONET,
and if create_link() wins configfs_rmdir() will return -EBUSY.

Reported-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Tested-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
2017-06-12 13:20:10 +02:00
Linus Torvalds 7c0f6ba682 Replace <asm/uaccess.h> with <linux/uaccess.h> globally
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
  sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-24 11:46:01 -08:00
Miklos Szeredi dfeef68862 vfs: remove ".readlink = generic_readlink" assignments
If .readlink == NULL implies generic_readlink().

Generated by:

to_del="\.readlink.*=.*generic_readlink"
for i in `git grep -l $to_del`; do sed -i "/$to_del"/d $i; done

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-12-09 16:45:04 +01:00
Al Viro 3873691e5a Merge remote-tracking branch 'ovl/rename2' into for-linus 2016-10-10 23:02:51 -04:00
Deepa Dinamani c2050a454c fs: Replace current_fs_time() with current_time()
current_fs_time() uses struct super_block* as an argument.
As per Linus's suggestion, this is changed to take struct
inode* as a parameter instead. This is because the function
is primarily meant for vfs inode timestamps.
Also the function was renamed as per Arnd's suggestion.

Change all calls to current_fs_time() to use the new
current_time() function instead. current_fs_time() will be
deleted.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-27 21:06:22 -04:00
Phil Turnbull 42857cf512 configfs: Return -EFBIG from configfs_write_bin_file.
The check for writing more than cb_max_size bytes does not 'goto out' so
it is a no-op which allows users to vmalloc an arbitrary amount.

Fixes: 03607ace80 ("configfs: implement binary attributes")
Cc: stable@kernel.org
Signed-off-by: Phil Turnbull <phil.turnbull@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-09-16 12:58:28 +02:00
Tal Shorer 3dc3afadeb configfs: don't set buffer_needs_fill to zero if show() returns error
A confgifs attribute's show() callback is called once the first time
the user attempts to read from it. If it returns an error, that
error is returned to the user. However, the open file's
buffer_needs_fill is still set to zero and consecutive read() calls
will find an empty buffer that doesn't need filling and return 0 to
the user. This could give the user the wrong impression that the
attribute was read successfully.

Fix this by not setting buffer_needs_fill if show() returns an error,
making consecutive read() calls call show() again and either get an
error again or get data.

Signed-off-by: Tal Shorer <tal.shorer@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-07-10 21:02:18 +09:00
Marek Vasut f8608985f8 configfs: Remove ppos increment in configfs_write_bin_file
The simple_write_to_buffer() already increments the @ppos on success,
see fs/libfs.c simple_write_to_buffer() comment:

"
On success, the number of bytes written is returned and the offset @ppos
advanced by this number, or negative value is returned on error.
"

If the configfs_write_bin_file() is invoked with @count smaller than the
total length of the written binary file, it will be invoked multiple times.
Since configfs_write_bin_file() increments @ppos on success, after calling
simple_write_to_buffer(), the @ppos is incremented twice.

Subsequent invocation of configfs_write_bin_file() will result in the next
piece of data being written to the offset twice as long as the length of
the previous write, thus creating buffer with "holes" in it.

The simple testcase using DTO follows:
  $ mkdir /sys/kernel/config/device-tree/overlays/1
  $ dd bs=1 if=foo.dtbo of=/sys/kernel/config/device-tree/overlays/1/dtbo
Without this patch, the testcase will result in twice as big buffer in the
kernel, which is then passed to the cfs_overlay_item_dtbo_write() .

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
2016-06-30 11:28:55 +02:00
Al Viro a01b3007ff configfs_readdir(): make safe under shared lock
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-09 11:41:13 -04:00
Al Viro 9902af79c0 parallel lookups: actual switch to rwsem
ta-da!

The main issue is the lack of down_write_killable(), so the places
like readdir.c switched to plain inode_lock(); once killable
variants of rwsem primitives appear, that'll be dealt with.

lockdep side also might need more work

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02 19:49:28 -04:00
Al Viro 48f35b7b73 configfs_detach_prep(): make sure that wait_mutex won't go away
grab a reference to dentry we'd got the sucker from, and return
that dentry via *wait, rather than just returning the address of
->i_mutex.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02 19:47:22 -04:00
Kirill A. Shutemov 09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
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: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00
Linus Torvalds 3c2de27d79 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:

 - Preparations of parallel lookups (the remaining main obstacle is the
   need to move security_d_instantiate(); once that becomes safe, the
   rest will be a matter of rather short series local to fs/*.c

 - preadv2/pwritev2 series from Christoph

 - assorted fixes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits)
  splice: handle zero nr_pages in splice_to_pipe()
  vfs: show_vfsstat: do not ignore errors from show_devname method
  dcache.c: new helper: __d_add()
  don't bother with __d_instantiate(dentry, NULL)
  untangle fsnotify_d_instantiate() a bit
  uninline d_add()
  replace d_add_unique() with saner primitive
  quota: use lookup_one_len_unlocked()
  cifs_get_root(): use lookup_one_len_unlocked()
  nfs_lookup: don't bother with d_instantiate(dentry, NULL)
  kill dentry_unhash()
  ceph_fill_trace(): don't bother with d_instantiate(dn, NULL)
  autofs4: don't bother with d_instantiate(dentry, NULL) in ->lookup()
  configfs: move d_rehash() into configfs_create() for regular files
  ceph: don't bother with d_rehash() in splice_dentry()
  namei: teach lookup_slow() to skip revalidate
  namei: massage lookup_slow() to be usable by lookup_one_len_unlocked()
  lookup_one_len_unlocked(): use lookup_dcache()
  namei: simplify invalidation logics in lookup_dcache()
  namei: change calling conventions for lookup_{fast,slow} and follow_managed()
  ...
2016-03-19 18:52:29 -07:00
Al Viro 5cf3b560af configfs: move d_rehash() into configfs_create() for regular files
... and turn it into d_add in there

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-14 00:15:55 -04:00
Christoph Hellwig 1ae1602de0 configfs: switch ->default groups to a linked list
Replace the current NULL-terminated array of default groups with a linked
list.  This gets rid of lots of nasty code to size and/or dynamically
allocate the array.

While we're at it also provide a conveniant helper to remove the default
groups.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Felipe Balbi <balbi@kernel.org>		[drivers/usb/gadget]
Acked-by: Joel Becker <jlbec@evilplan.org>
Acked-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
2016-03-06 16:11:24 +01:00
Deepa Dinamani b1f1a29d8f configfs: Replace CURRENT_TIME by current_fs_time()
CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_fs_time() instead.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-02-26 10:42:35 +01:00
Al Viro 5955102c99 wrappers for ->i_mutex access
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22 18:04:28 -05:00
Linus Torvalds 71e4634e00 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger:
 "The highlights this round include:

   - Introduce configfs support for unlocked configfs_depend_item()
     (krzysztof + andrezej)
   - Conversion of usb-gadget target driver to new function registration
     interface (andrzej + sebastian)
   - Enable qla2xxx FC target mode support for Extended Logins (himansu +
     giridhar)
   - Enable qla2xxx FC target mode support for Exchange Offload (himansu +
     giridhar)
   - Add qla2xxx FC target mode irq affinity notification + selective
     command queuing.  (quinn + himanshu)
   - Fix iscsi-target deadlock in se_node_acl configfs deletion (sagi +
     nab)
   - Convert se_node_acl configfs deletion + se_node_acl->queue_depth to
     proper se_session->sess_kref + target_get_session() usage.  (hch +
     sagi + nab)
   - Fix long-standing race between se_node_acl->acl_kref get and
     get_initiator_node_acl() lookup.  (hch + nab)
   - Fix target/user block-size handling, and make sure netlink reaches
     all network namespaces (sheng + andy)

  Note there is an outstanding bug-fix series for remote I_T nexus port
  TMR LUN_RESET has been posted and still being tested, and will likely
  become post -rc1 material at this point"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (56 commits)
  scsi: qla2xxxx: avoid type mismatch in comparison
  target/user: Make sure netlink would reach all network namespaces
  target: Obtain se_node_acl->acl_kref during get_initiator_node_acl
  target: Convert ACL change queue_depth se_session reference usage
  iscsi-target: Fix potential dead-lock during node acl delete
  ib_srpt: Convert acl lookup to modern get_initiator_node_acl usage
  tcm_fc: Convert acl lookup to modern get_initiator_node_acl usage
  tcm_fc: Wait for command completion before freeing a session
  target: Fix a memory leak in target_dev_lba_map_store()
  target: Support aborting tasks with a 64-bit tag
  usb/gadget: Remove set-but-not-used variables
  target: Remove an unused variable
  target: Fix indentation in target_core_configfs.c
  target/user: Allow user to set block size before enabling device
  iser-target: Fix non negative ERR_PTR isert_device_get usage
  target/fcoe: Add tag support to tcm_fc
  qla2xxx: Check for online flag instead of active reset when transmitting responses
  qla2xxx: Set all queues to 4k
  qla2xxx: Disable ZIO at start time.
  qla2xxx: Move atioq to a different lock to reduce lock contention
  ...
2016-01-20 17:20:53 -08:00
Linus Torvalds 420d12d6ad Configfs changes for the 4.5 merge window:
- I'm assisting Joel as co-maintainer and patch monkey now, and you will
    see pull reuquests from me for a while
  - Besides the MAINTAINERS update there is just a single change, which
    adds support for binary attributes to configfs, which are very similar
    to the sysfs binary attributes.  Thanks to Pantelis Antoniou!
  - You will see another actually bigger set of configfs changes in the
    SCSI target pull from Nic - those were merged before this new tree
    even existed
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Merge tag 'configfs-for-linus' of git://git.infradead.org/users/hch/configfs

Pull configfs updates from Christoph Hellwig:
 "I'm assisting Joel as co-maintainer and patch monkey now, and you will
  see pull reuquests from me for a while.

  Besides the MAINTAINERS update there is just a single change, which
  adds support for binary attributes to configfs, which are very similar
  to the sysfs binary attributes.  Thanks to Pantelis Antoniou!

  You will see another actually bigger set of configfs changes in the
  SCSI target pull from Nic - those were merged before this new tree
  even existed"

* tag 'configfs-for-linus' of git://git.infradead.org/users/hch/configfs:
  configfs: add myself as co-maintainer, updated git tree
  configfs: implement binary attributes
2016-01-12 18:15:34 -08:00
Pantelis Antoniou 03607ace80 configfs: implement binary attributes
ConfigFS lacked binary attributes up until now. This patch
introduces support for binary attributes in a somewhat similar
manner of sysfs binary attributes albeit with changes that
fit the configfs usage model.

Problems that configfs binary attributes fix are everything that
requires a binary blob as part of the configuration of a resource,
such as bitstream loading for FPGAs, DTBs for dynamically created
devices etc.

Look at Documentation/filesystems/configfs/configfs.txt for internals
and howto use them.

This patch is against linux-next as of today that contains
Christoph's configfs rework.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
[hch: folded a fix from Geert Uytterhoeven <geert+renesas@glider.be>]
[hch: a few tiny updates based on review feedback]
Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-01-04 12:31:46 +01:00
Al Viro fceef393a5 switch ->get_link() to delayed_call, kill ->put_link()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-30 13:01:03 -05:00
Al Viro cd3417c8fc kill free_page_put_link()
all callers are better off with kfree_put_link()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-29 16:03:53 -05:00
Krzysztof Opasiak d79d75b5c5 fs: configfs: Add unlocked version of configfs_depend_item()
This change is necessary for the SCSI target usb gadget composed with
configfs. In this case configfs will be used for two different purposes:
to compose a usb gadget and to configure the target part. If an instance
of tcm function is created in $CONFIGFS_ROOT/usb_gadget/<gadget>/functions
a tpg can be created in $CONFIGFS_ROOT/target/usb_gadget/<wwn>/, but after
a tpg is created the tcm function must not be removed until its
corresponding tpg is gone. While the configfs_depend/undepend_item() are
meant exactly for creating this kind of dependencies, they are not suitable
if the other kernel subsystem happens to be another subsystem in configfs,
so this patch adds unlocked versions meant for configfs callbacks.

Above description has been provided by:
Andrzej Pietrasiewicz <andrzej.p@samsung.com>

In configfs_depend_item() we have to consider two possible cases:

1) When we are called to depend another item in the same subsystem
   as caller
	In this case we should skip locking configfs root as we know
	that configfs is in valid state and our subsystem will not
	be unregistered during this call.

2) When we are called to depend item in different subsystem than
   our caller
	In this case we are also sure that configfs is in valid state
	but we have to lock root of configfs to avoid unregistration
	of target's subsystem. As it is other than caller's subsystem,
	there may be nothing what protects us against unregistration
	of that subsystem.

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-12-20 18:04:03 -08:00
Krzysztof Opasiak 9a70adfff3 fs: configfs: Factor out configfs_find_subsys_dentry()
configfs_depend_item() is quite complicated and should
be split up into smaller functions. This also allow to
share this code with other functions.

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-12-20 18:04:01 -08:00
Krzysztof Opasiak 9fb434e754 fs: configfs: Factor out configfs_do_depend_item()
configfs_depend_item() is quite complicated and should
be split up into smaller functions. This also allow to
share this code with other functions.

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-12-20 18:03:59 -08:00
Krzysztof Opasiak 9a9e3415ed fs: configfs: Drop unused parameter from configfs_undepend_item()
subsys parameter is never used by configfs_undepend_item()
so there is no point in passing it to this function.

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-12-20 18:03:57 -08:00
Al Viro 6b2553918d replace ->follow_link() with new method that could stay in RCU mode
new method: ->get_link(); replacement of ->follow_link().  The differences
are:
	* inode and dentry are passed separately
	* might be called both in RCU and non-RCU mode;
the former is indicated by passing it a NULL dentry.
	* when called that way it isn't allowed to block
and should return ERR_PTR(-ECHILD) if it needs to be called
in non-RCU mode.

It's a flagday change - the old method is gone, all in-tree instances
converted.  Conversion isn't hard; said that, so far very few instances
do not immediately bail out when called in RCU mode.  That'll change
in the next commits.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-08 22:41:54 -05:00
Daniel Baluta 5cf6a51e60 configfs: allow dynamic group creation
This patchset introduces IIO software triggers, offers a way of configuring
them via configfs and adds the IIO hrtimer based interrupt source to be used
with software triggers.

The architecture is now split in 3 parts, to remove all IIO trigger specific
parts from IIO configfs core:

(1) IIO configfs - creates the root of the IIO configfs subsys.
(2) IIO software triggers - software trigger implementation, dynamically
    creating /config/iio/triggers group.
(3) IIO hrtimer trigger - is the first interrupt source for software triggers
    (with syfs to follow). Each trigger type can implement its own set of
    attributes.

Lockdep seems to be happy with the locking in configfs patch.

This patch (of 5):

We don't want to hardcode default groups at subsystem
creation time. We export:
	* configfs_register_group
	* configfs_unregister_group
to allow drivers to programatically create/destroy groups
later, after module init time.

This is needed for IIO configfs support.

(akpm: the other 4 patches to be merged via the IIO tree)

Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Suggested-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Joel Becker <jlbec@evilplan.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Octavian Purdila <octavian.purdila@intel.com>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Adriana Reus <adriana.reus@intel.com>
Cc: Cristina Opriceana <cristina.opriceana@gmail.com>
Cc: Peter Meerwald <pmeerw@pmeerw.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-20 16:17:32 -08:00
Christoph Hellwig 517982229f configfs: remove old API
Remove the old show_attribute and store_attribute methods and update
the documentation.  Also replace the two C samples with a single new
one in the proper samples directory where people expect to find it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-10-13 22:17:57 -07:00
Christoph Hellwig 870823e629 configfs: add show and store methods to struct configfs_attribute
Add methods to struct configfs_attribute to directly show and store
attributes without adding boilerplate code to every user.  In addition
to the methods this also adds 3 helper macros to define read/write,
read-only and write-only attributes with a single line of code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Nicholas Bellinger <nab@linux-iscsi.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2015-10-13 22:08:43 -07:00
Nicolas Iooss 3958b79266 configfs: fix kernel infoleak through user-controlled format string
Some modules call config_item_init_type_name() and config_group_init_type_name()
with parameter "name" directly controlled by userspace.  These two
functions call config_item_set_name() with this name used as a format
string, which can be used to leak information such as content of the
stack to userspace.

For example, make_netconsole_target() in netconsole module calls
config_item_init_type_name() with the name of a newly-created directory.
This means that the following commands give some unexpected output, with
configfs mounted in /sys/kernel/config/ and on a system with a
configured eth0 ethernet interface:

    # modprobe netconsole
    # mkdir /sys/kernel/config/netconsole/target_%lx
    # echo eth0 > /sys/kernel/config/netconsole/target_%lx/dev_name
    # echo 1 > /sys/kernel/config/netconsole/target_%lx/enabled
    # echo eth0 > /sys/kernel/config/netconsole/target_%lx/dev_name
    # dmesg |tail -n1
    [  142.697668] netconsole: target (target_ffffffffc0ae8080) is
    enabled, disable to update parameters

The directory name is correct but %lx has been interpreted in the
internal item name, displayed here in the error message used by
store_dev_name() in drivers/net/netconsole.c.

To fix this, update every caller of config_item_set_name to use "%s"
when operating on untrusted input.

This issue was found using -Wformat-security gcc flag, once a __printf
attribute has been added to config_item_set_name().

Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <balbi@ti.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-17 16:39:53 -07:00
Linus Torvalds 1dc51b8288 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...
2015-07-04 19:36:06 -07:00
Linus Torvalds 0cbee99269 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace updates from Eric Biederman:
 "Long ago and far away when user namespaces where young it was realized
  that allowing fresh mounts of proc and sysfs with only user namespace
  permissions could violate the basic rule that only root gets to decide
  if proc or sysfs should be mounted at all.

  Some hacks were put in place to reduce the worst of the damage could
  be done, and the common sense rule was adopted that fresh mounts of
  proc and sysfs should allow no more than bind mounts of proc and
  sysfs.  Unfortunately that rule has not been fully enforced.

  There are two kinds of gaps in that enforcement.  Only filesystems
  mounted on empty directories of proc and sysfs should be ignored but
  the test for empty directories was insufficient.  So in my tree
  directories on proc, sysctl and sysfs that will always be empty are
  created specially.  Every other technique is imperfect as an ordinary
  directory can have entries added even after a readdir returns and
  shows that the directory is empty.  Special creation of directories
  for mount points makes the code in the kernel a smidge clearer about
  it's purpose.  I asked container developers from the various container
  projects to help test this and no holes were found in the set of mount
  points on proc and sysfs that are created specially.

  This set of changes also starts enforcing the mount flags of fresh
  mounts of proc and sysfs are consistent with the existing mount of
  proc and sysfs.  I expected this to be the boring part of the work but
  unfortunately unprivileged userspace winds up mounting fresh copies of
  proc and sysfs with noexec and nosuid clear when root set those flags
  on the previous mount of proc and sysfs.  So for now only the atime,
  read-only and nodev attributes which userspace happens to keep
  consistent are enforced.  Dealing with the noexec and nosuid
  attributes remains for another time.

  This set of changes also addresses an issue with how open file
  descriptors from /proc/<pid>/ns/* are displayed.  Recently readlink of
  /proc/<pid>/fd has been triggering a WARN_ON that has not been
  meaningful since it was added (as all of the code in the kernel was
  converted) and is not now actively wrong.

  There is also a short list of issues that have not been fixed yet that
  I will mention briefly.

  It is possible to rename a directory from below to above a bind mount.
  At which point any directory pointers below the renamed directory can
  be walked up to the root directory of the filesystem.  With user
  namespaces enabled a bind mount of the bind mount can be created
  allowing the user to pick a directory whose children they can rename
  to outside of the bind mount.  This is challenging to fix and doubly
  so because all obvious solutions must touch code that is in the
  performance part of pathname resolution.

  As mentioned above there is also a question of how to ensure that
  developers by accident or with purpose do not introduce exectuable
  files on sysfs and proc and in doing so introduce security regressions
  in the current userspace that will not be immediately obvious and as
  such are likely to require breaking userspace in painful ways once
  they are recognized"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  vfs: Remove incorrect debugging WARN in prepend_path
  mnt: Update fs_fully_visible to test for permanently empty directories
  sysfs: Create mountpoints with sysfs_create_mount_point
  sysfs: Add support for permanently empty directories to serve as mount points.
  kernfs: Add support for always empty directories.
  proc: Allow creating permanently empty directories that serve as mount points
  sysctl: Allow creating permanently empty directories that serve as mountpoints.
  fs: Add helper functions for permanently empty directories.
  vfs: Ignore unlocked mounts in fs_fully_visible
  mnt: Modify fs_fully_visible to deal with locked ro nodev and atime
  mnt: Refactor the logic for mounting sysfs and proc in a user namespace
2015-07-03 15:20:57 -07:00
Eric W. Biederman f9bb48825a sysfs: Create mountpoints with sysfs_create_mount_point
This allows for better documentation in the code and
it allows for a simpler and fully correct version of
fs_fully_visible to be written.

The mount points converted and their filesystems are:
/sys/hypervisor/s390/       s390_hypfs
/sys/kernel/config/         configfs
/sys/kernel/debug/          debugfs
/sys/firmware/efi/efivars/  efivarfs
/sys/fs/fuse/connections/   fusectl
/sys/fs/pstore/             pstore
/sys/kernel/tracing/        tracefs
/sys/fs/cgroup/             cgroup
/sys/kernel/security/       securityfs
/sys/fs/selinux/            selinuxfs
/sys/fs/smackfs/            smackfs

Cc: stable@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-07-01 10:36:47 -05:00
Fabian Frederick 5286d20c4e configfs: unexport/make static config_item_init()
config_item_init() is only used in item.c

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-24 17:49:39 -07:00
Al Viro dc3f4198ea make simple_positive() public
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:02:01 -04:00
Al Viro ecc087ff14 new helper: free_page_put_link()
similar to kfree_put_link()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11 08:13:13 -04:00
Al Viro 5f2c4179e1 switch ->put_link() from dentry to inode
only one instance looks at that argument at all; that sole
exception wants inode rather than dentry.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11 08:13:12 -04:00
Al Viro 6e77137b36 don't pass nameidata to ->follow_link()
its only use is getting passed to nd_jump_link(), which can obtain
it from current->nameidata

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10 22:20:15 -04:00
Al Viro 680baacbca new ->follow_link() and ->put_link() calling conventions
a) instead of storing the symlink body (via nd_set_link()) and returning
an opaque pointer later passed to ->put_link(), ->follow_link() _stores_
that opaque pointer (into void * passed by address by caller) and returns
the symlink body.  Returning ERR_PTR() on error, NULL on jump (procfs magic
symlinks) and pointer to symlink body for normal symlinks.  Stored pointer
is ignored in all cases except the last one.

Storing NULL for opaque pointer (or not storing it at all) means no call
of ->put_link().

b) the body used to be passed to ->put_link() implicitly (via nameidata).
Now only the opaque pointer is.  In the cases when we used the symlink body
to free stuff, ->follow_link() now should store it as opaque pointer in addition
to returning it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10 22:19:45 -04:00
Daniel Baluta f5b697700c configfs: init configfs module earlier at boot time
We need this earlier in the boot process to allow various subsystems to
use configfs (e.g Industrial IIO).

Also, debugfs is at core_initcall level and configfs should be on the same
level from infrastructure point of view.

Signed-off-by: Daniel Baluta <daniel.baluta@intel.com>
Suggested-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05 17:10:11 -07:00
David Howells 2b0143b5c9 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 <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:06:57 -04:00
David Howells 6683de3886 configfs: Fix inconsistent use of file_inode() vs file->f_path.dentry->d_inode
Fix inconsistent use of file_inode() vs file->f_path.dentry->d_inode.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-15 15:05:31 -04:00
David Howells 112fc894a7 configfs: Fix potential NULL d_inode dereference
Code that does this:

		if (!(d_unhashed(dentry) && dentry->d_inode)) {
			...
			simple_unlink(parent->d_inode, dentry);
		}

is broken because:

    !(d_unhashed(dentry) && dentry->d_inode)

is equivalent to:

    !d_unhashed(dentry) || !dentry->d_inode

so it is possible to get into simple_unlink() with dentry->d_inode == NULL.

simple_unlink(), however, assumes dentry->d_inode cannot be NULL.

I think that what was meant is this:

    !d_unhashed(dentry) && dentry->d_inode

and that the logical-not operator or the final close-bracket was misplaced.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-20 04:56:43 -05:00
Al Viro 28444a2bde configfs_add_file: fold into its sole caller
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-17 22:16:46 -05:00
Al Viro 1cf97d0d3a configfs: fold create_dir() into its only caller
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-17 22:16:35 -05:00
Al Viro c88b1e70ae configfs: configfs_create() init callback is never NULL and it never fails
... so make it return void and drop the check for it being non-NULL

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-17 22:15:47 -05:00
Christoph Hellwig b83ae6d421 fs: remove mapping->backing_dev_info
Now that we never use the backing_dev_info pointer in struct address_space
we can simply remove it and save 4 to 8 bytes in every inode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 14:03:05 -07:00
Christoph Hellwig b4caecd480 fs: introduce f_op->mmap_capabilities for nommu mmap support
Since "BDI: Provide backing device capability information [try #3]" the
backing_dev_info structure also provides flags for the kind of mmap
operation available in a nommu environment, which is entirely unrelated
to it's original purpose.

Introduce a new nommu-only file operation to provide this information to
the nommu mmap code instead.  Splitting this from the backing_dev_info
structure allows to remove lots of backing_dev_info instance that aren't
otherwise needed, and entirely gets rid of the concept of providing a
backing_dev_info for a character device.  It also removes the need for
the mtd_inodefs filesystem.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 14:02:58 -07:00
Al Viro a455589f18 assorted conversions to %p[dD]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-19 13:01:20 -05:00
Fabian Frederick 1d88aa441f fs/configfs: use pr_fmt
Add pr_fmt based on module name.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:53 -07:00
Fabian Frederick c668693133 fs/configfs: convert printk to pr_foo()
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:53 -07:00
Fabian Frederick f6b1fe7c27 fs/configs/item.c: kernel-doc fixes + clean-up
Fix function parameter documentation

EXPORT_SYMBOLS moved after corresponding functions

Small coding style and checkpatch warning fixes

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Acked-by: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:53 -07:00
Junxiao Bi 76ae281f63 configfs: fix race between dentry put and lookup
A race window in configfs, it starts from one dentry is UNHASHED and end
before configfs_d_iput is called.  In this window, if a lookup happen,
since the original dentry was UNHASHED, so a new dentry will be
allocated, and then in configfs_attach_attr(), sd->s_dentry will be
updated to the new dentry.  Then in configfs_d_iput(),
BUG_ON(sd->s_dentry != dentry) will be triggered and system panic.

sys_open:                     sys_close:
 ...                           fput
                                dput
                                 dentry_kill
                                  __d_drop <--- dentry unhashed here,
                                           but sd->dentry still point
                                           to this dentry.

 lookup_real
  configfs_lookup
   configfs_attach_attr---> update sd->s_dentry
                            to new allocated dentry here.

                                   d_kill
                                     configfs_d_iput <--- BUG_ON(sd->s_dentry != dentry)
                                                     triggered here.

To fix it, change configfs_d_iput to not update sd->s_dentry if
sd->s_count > 2, that means there are another dentry is using the sd
beside the one that is going to be put.  Use configfs_dirent_lock in
configfs_attach_attr to sync with configfs_d_iput.

With the following steps, you can reproduce the bug.

1. enable ocfs2, this will mount configfs at /sys/kernel/config and
   fill configure in it.

2. run the following script.
	while [ 1 ]; do cat /sys/kernel/config/cluster/$your_cluster_name/idle_timeout_ms > /dev/null; done &
	while [ 1 ]; do cat /sys/kernel/config/cluster/$your_cluster_name/idle_timeout_ms > /dev/null; done &

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-21 16:42:27 -08:00
Al Viro b26d4cd385 consolidate simple ->d_delete() instances
Rename simple_delete_dentry() to always_delete_dentry() and export it.
Export simple_dentry_operations, while we are at it, and get rid of
their duplicates

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-15 22:04:17 -05:00
Linus Torvalds 41d9884c44 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs stuff from Al Viro:
 "O_TMPFILE ABI changes, Oleg's fput() series, misc cleanups, including
  making simple_lookup() usable for filesystems with non-NULL s_d_op,
  which allows us to get rid of quite a bit of ugliness"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  sunrpc: now we can just set ->s_d_op
  cgroup: we can use simple_lookup() now
  efivarfs: we can use simple_lookup() now
  make simple_lookup() usable for filesystems that set ->s_d_op
  configfs: don't open-code d_alloc_name()
  __rpc_lookup_create_exclusive: pass string instead of qstr
  rpc_create_*_dir: don't bother with qstr
  llist: llist_add() can use llist_add_batch()
  llist: fix/simplify llist_add() and llist_add_batch()
  fput: turn "list_head delayed_fput_list" into llist_head
  fs/file_table.c:fput(): add comment
  Safer ABI for O_TMPFILE
2013-07-14 11:42:26 -07:00
Al Viro ec193cf5af configfs: don't open-code d_alloc_name()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-14 17:16:52 +04:00
Linus Torvalds c75e24752c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull third set of VFS updates from Al Viro:
 "Misc stuff all over the place.  There will be one more pile in a
  couple of days"

This is an "evil merge" that also uses the new d_count helper in
fs/configfs/dir.c, missed by commit 84d08fa888 ("helper for reading
->d_count")

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ncpfs: fix error return code in ncp_parse_options()
  locks: move file_lock_list to a set of percpu hlist_heads and convert file_lock_lock to an lglock
  seq_file: add seq_list_*_percpu helpers
  f2fs: fix readdir incorrectness
  mode_t whack-a-mole...
  lustre: kill the pointless wrapper
  helper for reading ->d_count
2013-07-09 11:26:44 -07:00
Dan Carpenter 7121064b21 configfs: use capped length for ->store_attribute()
The difference between "count" and "len" is that "len" is capped at
4095.  Changing it like this makes it match how sysfs_write_file() is
implemented.

This is a static analysis patch.  I haven't found any store_attribute()
functions where this change makes a difference.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:23 -07:00
Al Viro 52018855e6 [readdir] convert configfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:56:30 +04:00
Eric W. Biederman 7f78e03513 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 <serge.hallyn@canonical.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reported-by: Kees Cook <keescook@google.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-03 19:36:31 -08:00
Linus Torvalds d895cb1af1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile (part one) from Al Viro:
 "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
  locking violations, etc.

  The most visible changes here are death of FS_REVAL_DOT (replaced with
  "has ->d_weak_revalidate()") and a new helper getting from struct file
  to inode.  Some bits of preparation to xattr method interface changes.

  Misc patches by various people sent this cycle *and* ocfs2 fixes from
  several cycles ago that should've been upstream right then.

  PS: the next vfs pile will be xattr stuff."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
  saner proc_get_inode() calling conventions
  proc: avoid extra pde_put() in proc_fill_super()
  fs: change return values from -EACCES to -EPERM
  fs/exec.c: make bprm_mm_init() static
  ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
  ocfs2: fix possible use-after-free with AIO
  ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
  get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
  target: writev() on single-element vector is pointless
  export kernel_write(), convert open-coded instances
  fs: encode_fh: return FILEID_INVALID if invalid fid_type
  kill f_vfsmnt
  vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
  nfsd: handle vfs_getattr errors in acl protocol
  switch vfs_getattr() to struct path
  default SET_PERSONALITY() in linux/elf.h
  ceph: prepopulate inodes only when request is aborted
  d_hash_and_lookup(): export, switch open-coded instances
  9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
  9p: split dropping the acls from v9fs_set_create_acl()
  ...
2013-02-26 20:16:07 -08:00
Al Viro 496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Wei Yongjun 49deb4bc22 configfs: move the dereference below the NULL test
The dereference should be moved below the NULL test.

spatch with a semantic match is used to found this.
(http://coccinelle.lip6.fr/)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-21 17:22:19 -08:00
Andrew Morton 965c8e59cf lseek: the "whence" argument is called "whence"
But the kernel decided to call it "origin" instead.  Fix most of the
sites.

Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-17 17:15:12 -08:00
Eric W. Biederman 69552c0c50 userns: Convert configfs to use kuid and kgid where appropriate
Cc: Joel Becker <jlbec@evilplan.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-09-18 01:01:37 -07:00
Al Viro 00cd8dd3bf stop passing nameidata to ->lookup()
Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument.  And getting rid of that
completely would require splitting ->lookup() into a couple
of methods (at least), so let's leave that alone for now...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:32 +04:00
Al Viro 2a152ad3a5 make configfs_pin_fs() return root dentry on success
... and make configfs_mnt static

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:48 -04:00
Al Viro 0dd6c08a00 configfs: configfs_create_dir() has parent dentry in dentry->d_parent
no need to play sick games with parent item, internal mount, etc.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:47 -04:00
Al Viro 16d13b59b5 configfs: sanitize configfs_create()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:47 -04:00
Al Viro b7c177fcd2 configfs: kill configfs_sb
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:47 -04:00
Al Viro 81d44ed159 configfs: don't bother with checks for mkdir/rmdir/unlink/symlink in root
just give root directory separate inode_operations without all those
methods...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:46 -04:00
Al Viro 48fde701af switch open-coded instances of d_make_root() to new helper
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20 21:29:35 -04:00
Al Viro 439475140b configfs: convert to umode_t
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:57 -05:00
Al Viro 18bb1db3e7 switch vfs_mkdir() and ->mkdir() to umode_t
vfs_mkdir() gets int, but immediately drops everything that might not
fit into umode_t and that's the only caller of ->mkdir()...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:53 -05:00
Al Viro c972b4bc83 vfs: live vfsmounts never have NULL ->mnt_sb
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:52:42 -05:00
Al Viro 4c1d5a64f1 vfs: for usbfs, etc. internal vfsmounts ->mnt_sb->s_root == ->mnt_root
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:52:41 -05:00
Al Viro 7c6455e368 configfs: register_filesystem() called too early
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-13 12:35:15 -05:00
Paul Bolle 395cf9691d doc: fix broken references
There are numerous broken references to Documentation files (in other
Documentation files, in comments, etc.). These broken references are
caused by typo's in the references, and by renames or removals of the
Documentation files. Some broken references are simply odd.

Fix these broken references, sometimes by dropping the irrelevant text
they were part of.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-09-27 18:08:04 +02:00
Sage Weil 98702467f8 configfs: remove unnecessary dentry_unhash on rmdir, dir rename
configfs does not have problems with references to unlinked directories.

CC: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-28 01:02:54 -04:00
Linus Torvalds 32e51f141f Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (25 commits)
  cifs: remove unnecessary dentry_unhash on rmdir/rename_dir
  ocfs2: remove unnecessary dentry_unhash on rmdir/rename_dir
  exofs: remove unnecessary dentry_unhash on rmdir/rename_dir
  nfs: remove unnecessary dentry_unhash on rmdir/rename_dir
  ext2: remove unnecessary dentry_unhash on rmdir/rename_dir
  ext3: remove unnecessary dentry_unhash on rmdir/rename_dir
  ext4: remove unnecessary dentry_unhash on rmdir/rename_dir
  btrfs: remove unnecessary dentry_unhash in rmdir/rename_dir
  ceph: remove unnecessary dentry_unhash calls
  vfs: clean up vfs_rename_other
  vfs: clean up vfs_rename_dir
  vfs: clean up vfs_rmdir
  vfs: fix vfs_rename_dir for FS_RENAME_DOES_D_MOVE filesystems
  libfs: drop unneeded dentry_unhash
  vfs: update dentry_unhash() comment
  vfs: push dentry_unhash on rename_dir into file systems
  vfs: push dentry_unhash on rmdir into file systems
  vfs: remove dget() from dentry_unhash()
  vfs: dentry_unhash immediately prior to rmdir
  vfs: Block mmapped writes while the fs is frozen
  ...
2011-05-26 09:52:14 -07:00
Sage Weil 79bf7c732b vfs: push dentry_unhash on rmdir into file systems
Only a few file systems need this.  Start by pushing it down into each
fs rmdir method (except gfs2 and xfs) so it can be dealt with on a per-fs
basis.

This does not change behavior for any in-tree file systems.

Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-26 07:26:47 -04:00
Joel Becker 24307aa1e7 configfs: Fix race between configfs_readdir() and configfs_d_iput()
configfs_readdir() will use the existing inode numbers of inodes in the
dcache, but it makes them up for attribute files that aren't currently
instantiated.  There is a race where a closing attribute file can be
tearing down at the same time as configfs_readdir() is trying to get its
inode number.

We want to get the inode number of open attribute files, because they
should match while instantiated.  We can't lock down the transition
where dentry->d_inode is set to NULL, so we just check for NULL there.
We can, however, ensure that an inode we find isn't iput() in
configfs_d_iput() until after we've accessed it.

Signed-off-by: Joel Becker <jlbec@evilplan.org>
2011-05-18 04:08:16 -07:00
Joel Becker df7f99670a configfs: Don't try to d_delete() negative dentries.
When configfs is faking mkdir() on its subsystem or default group
objects, it starts by adding a negative dentry.  It then tries to
instantiate the group.  If that should fail, it must clean up after
itself.

I was using d_delete() here, but configfs_attach_group() promises to
return an empty dentry on error.  d_delete() explodes with the entry
dentry.  Let's try d_drop() instead.  The unhashing is what we want for
our dentry.

Signed-off-by: Joel Becker <jlbec@evilplan.org>
2011-05-18 03:30:58 -07:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Nicholas Bellinger e205117285 configfs: change depends -> select SYSFS
This patch changes configfs to select SYSFS to fix the following:

warning: (TARGET_CORE && GFS2_FS) selects CONFIGFS_FS which has unmet direct dependencies (SYSFS)

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Acked-by: Joel Becker <jlbec@evilplan.org>
2011-01-16 21:22:29 +00:00
Al Viro d463a0c4b5 switch configfs
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:03:12 -05:00
Nick Piggin fb045adb99 fs: dcache reduce branches in lookup path
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.

Patched with:

git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:28 +11:00
Nick Piggin dc0474be3e fs: dcache rationalise dget variants
dget_locked was a shortcut to avoid the lazy lru manipulation when we already
held dcache_lock (lru manipulation was relatively cheap at that point).
However, how that the lru lock is an innermost one, we never hold it at any
caller, so the lock cost can now be avoided. We already have well working lazy
dcache LRU, so it should be fine to defer LRU manipulations to scan time.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:24 +11:00
Nick Piggin b5c84bf6f6 fs: dcache remove dcache_lock
dcache_lock no longer protects anything. remove it.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:23 +11:00
Nick Piggin da5029563a fs: dcache scale d_unhashed
Protect d_unhashed(dentry) condition with d_lock. This means keeping
DCACHE_UNHASHED bit in synch with hash manipulations.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:21 +11:00
Nick Piggin b7ab39f631 fs: dcache scale dentry refcount
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:21 +11:00
Nick Piggin fe15ce446b fs: change d_delete semantics
Change d_delete from a dentry deletion notification to a dentry caching
advise, more like ->drop_inode. Require it to be constant and idempotent,
and not take d_lock. This is how all existing filesystems use the callback
anyway.

This makes fine grained dentry locking of dput and dentry lru scanning
much simpler.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:18 +11:00
Nick Piggin fbc8d4c046 config fs: avoid switching ->d_op on live dentry
Switching d_op on a live dentry is racy in general, so avoid it. In this case
it is a negative dentry, which is safer, but there are still concurrent ops
which may be called on d_op in that case (eg. d_revalidate). So in general
a filesystem may not do this. Fix configfs so as not to do this.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:17 +11:00