* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
autofs4: deal with autofs4_write/autofs4_write races
autofs4: catatonic_mode vs. notify_daemon race
autofs4: autofs4_wait() vs. autofs4_catatonic_mode() race
hfsplus: creation of hidden dir on mount can fail
block_dev: Suppress bdev_cache_init() kmemleak warninig
fix shrink_dcache_parent() livelock
coda: switch coda_cnode_make() to sane API as well, clean coda_lookup()
coda: deal correctly with allocation failure from coda_cnode_makectl()
securityfs: fix object creation races
Just serialize the actual writing of packets into pipe on
a new mutex, independent from everything else in the locking
hierarchy. As soon as something has started feeding a piece
of packet into the pipe to daemon, we *want* everything else
about to try the same to wait until we are done.
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
we need to hold ->wq_mutex while we are forming the packet to send,
lest we have autofs4_catatonic_mode() setting wq->name.name to NULL
just as autofs4_notify_daemon() decides to memcpy() from it...
We do have check for catatonic mode immediately after that (under
->wq_mutex, as it ought to be) and packet won't be actually sent,
but it'll be too late for us if we oops on that memcpy() from NULL...
Fix is obvious - just extend the area covered by ->wq_mutex over
that switch and check whether it's catatonic *before* doing anything
else.
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We need to recheck ->catatonic after autofs4_wait() got ->wq_mutex
for good, or we might end up with wq inserted into queue after
autofs4_catatonic_mode() had done its thing. It will stick there
forever, since there won't be anything to clear its ->name.name.
A bit of a complication: validate_request() drops and regains ->wq_mutex.
It actually ends up the most convenient place to stick the check into...
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Andrew elucidates:
- First installmeant of MM. We have a HUGE number of MM patches this
time. It's crazy.
- MAINTAINERS updates
- backlight updates
- leds
- checkpatch updates
- misc ELF stuff
- rtc updates
- reiserfs
- procfs
- some misc other bits
* akpm: (124 commits)
user namespace: make signal.c respect user namespaces
workqueue: make alloc_workqueue() take printf fmt and args for name
procfs: add hidepid= and gid= mount options
procfs: parse mount options
procfs: introduce the /proc/<pid>/map_files/ directory
procfs: make proc_get_link to use dentry instead of inode
signal: add block_sigmask() for adding sigmask to current->blocked
sparc: make SA_NOMASK a synonym of SA_NODEFER
reiserfs: don't lock root inode searching
reiserfs: don't lock journal_init()
reiserfs: delay reiserfs lock until journal initialization
reiserfs: delete comments referring to the BKL
drivers/rtc/interface.c: fix alarm rollover when day or month is out-of-range
drivers/rtc/rtc-twl.c: add DT support for RTC inside twl4030/twl6030
drivers/rtc/: remove redundant spi driver bus initialization
drivers/rtc/rtc-jz4740.c: make jz4740_rtc_driver static
drivers/rtc/rtc-mc13xxx.c: make mc13xxx_rtc_idtable static
rtc: convert drivers/rtc/* to use module_platform_driver()
drivers/rtc/rtc-wm831x.c: convert to devm_kzalloc()
drivers/rtc/rtc-wm831x.c: remove unused period IRQ handler
...
Add support for mount options to restrict access to /proc/PID/
directories. The default backward-compatible "relaxed" behaviour is left
untouched.
The first mount option is called "hidepid" and its value defines how much
info about processes we want to be available for non-owners:
hidepid=0 (default) means the old behavior - anybody may read all
world-readable /proc/PID/* files.
hidepid=1 means users may not access any /proc/<pid>/ directories, but
their own. Sensitive files like cmdline, sched*, status are now protected
against other users. As permission checking done in proc_pid_permission()
and files' permissions are left untouched, programs expecting specific
files' modes are not confused.
hidepid=2 means hidepid=1 plus all /proc/PID/ will be invisible to other
users. It doesn't mean that it hides whether a process exists (it can be
learned by other means, e.g. by kill -0 $PID), but it hides process' euid
and egid. It compicates intruder's task of gathering info about running
processes, whether some daemon runs with elevated privileges, whether
another user runs some sensitive program, whether other users run any
program at all, etc.
gid=XXX defines a group that will be able to gather all processes' info
(as in hidepid=0 mode). This group should be used instead of putting
nonroot user in sudoers file or something. However, untrusted users (like
daemons, etc.) which are not supposed to monitor the tasks in the whole
system should not be added to the group.
hidepid=1 or higher is designed to restrict access to procfs files, which
might reveal some sensitive private information like precise keystrokes
timings:
http://www.openwall.com/lists/oss-security/2011/11/05/3
hidepid=1/2 doesn't break monitoring userspace tools. ps, top, pgrep, and
conky gracefully handle EPERM/ENOENT and behave as if the current user is
the only user running processes. pstree shows the process subtree which
contains "pstree" process.
Note: the patch doesn't deal with setuid/setgid issues of keeping
preopened descriptors of procfs files (like
https://lkml.org/lkml/2011/2/7/368). We rely on that the leaked
information like the scheduling counters of setuid apps doesn't threaten
anybody's privacy - only the user started the setuid program may read the
counters.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg KH <greg@kroah.com>
Cc: Theodore Tso <tytso@MIT.EDU>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: James Morris <jmorris@namei.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for procfs mount options. Actual mount options are coming in
the next patches.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg KH <greg@kroah.com>
Cc: Theodore Tso <tytso@MIT.EDU>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: James Morris <jmorris@namei.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This one behaves similarly to the /proc/<pid>/fd/ one - it contains
symlinks one for each mapping with file, the name of a symlink is
"vma->vm_start-vma->vm_end", the target is the file. Opening a symlink
results in a file that point exactly to the same inode as them vma's one.
For example the ls -l of some arbitrary /proc/<pid>/map_files/
| lr-x------ 1 root root 64 Aug 26 06:40 7f8f80403000-7f8f80404000 -> /lib64/libc-2.5.so
| lr-x------ 1 root root 64 Aug 26 06:40 7f8f8061e000-7f8f80620000 -> /lib64/libselinux.so.1
| lr-x------ 1 root root 64 Aug 26 06:40 7f8f80826000-7f8f80827000 -> /lib64/libacl.so.1.1.0
| lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a2f000-7f8f80a30000 -> /lib64/librt-2.5.so
| lr-x------ 1 root root 64 Aug 26 06:40 7f8f80a30000-7f8f80a4c000 -> /lib64/ld-2.5.so
This *helps* checkpointing process in three ways:
1. When dumping a task mappings we do know exact file that is mapped
by particular region. We do this by opening
/proc/$pid/map_files/$address symlink the way we do with file
descriptors.
2. This also helps in determining which anonymous shared mappings are
shared with each other by comparing the inodes of them.
3. When restoring a set of processes in case two of them has a mapping
shared, we map the memory by the 1st one and then open its
/proc/$pid/map_files/$address file and map it by the 2nd task.
Using /proc/$pid/maps for this is quite inconvenient since it brings
repeatable re-reading and reparsing for this text file which slows down
restore procedure significantly. Also as being pointed in (3) it is a way
easier to use top level shared mapping in children as
/proc/$pid/map_files/$address when needed.
[akpm@linux-foundation.org: coding-style fixes]
[gorcunov@openvz.org: make map_files depend on CHECKPOINT_RESTORE]
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: Vasiliy Kulikov <segoon@openwall.com>
Reviewed-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Tejun Heo <tj@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Prepare the ground for the next "map_files" patch which needs a name of a
link file to analyse.
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
journal_init() doesn't need the lock since no operation on the filesystem
is involved there. journal_read() and get_list_bitmap() have yet to be
reviewed carefully though before removing the lock there. Just keep the
it around these two calls for safety.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the mount path, transactions that are made before journal
initialization don't involve the filesystem. We can delay the reiserfs
lock until we play with the journal.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randomization of PIE load address is hard coded in binfmt_elf.c for X86
and ARM. Create a new Kconfig variable
(CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE) for this and use it instead. Thus
architecture specific policy is pushed out of the generic binfmt_elf.c and
into the architecture Kconfig files.
X86 and ARM Kconfigs are modified to select the new variable so there is
no change in behavior. A follow on patch will select it for MIPS too.
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
oom_score_adj is used for guarding processes from OOM-Killer. One of
problem is that it's inherited at fork(). When a daemon set oom_score_adj
and make children, it's hard to know where the value is set.
This patch adds some tracepoints useful for debugging. This patch adds
3 trace points.
- creating new task
- renaming a task (exec)
- set oom_score_adj
To debug, users need to enable some trace pointer. Maybe filtering is useful as
# EVENT=/sys/kernel/debug/tracing/events/task/
# echo "oom_score_adj != 0" > $EVENT/task_newtask/filter
# echo "oom_score_adj != 0" > $EVENT/task_rename/filter
# echo 1 > $EVENT/enable
# EVENT=/sys/kernel/debug/tracing/events/oom/
# echo 1 > $EVENT/enable
output will be like this.
# grep oom /sys/kernel/debug/tracing/trace
bash-7699 [007] d..3 5140.744510: oom_score_adj_update: pid=7699 comm=bash oom_score_adj=-1000
bash-7699 [007] ...1 5151.818022: task_newtask: pid=7729 comm=bash clone_flags=1200011 oom_score_adj=-1000
ls-7729 [003] ...2 5151.818504: task_rename: pid=7729 oldcomm=bash newcomm=ls oom_score_adj=-1000
bash-7699 [002] ...1 5175.701468: task_newtask: pid=7730 comm=bash clone_flags=1200011 oom_score_adj=-1000
grep-7730 [007] ...2 5175.701993: task_rename: pid=7730 oldcomm=bash newcomm=grep oom_score_adj=-1000
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tell the page allocator that pages allocated for a buffered write are
expected to become dirty soon.
Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Inode cache pruning indirectly reclaims page-cache by invalidating mapping
pages. Let's account them into reclaim-state to notice this progress in
memory reclaimer.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.10 (GNU/Linux)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=3oE5
-----END PGP SIGNATURE-----
Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Ext4 commits for 3.3 merge window
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (32 commits)
ext4: fix undefined behavior in ext4_fill_flex_info()
ext4: make more symbols static
ext4: make local symbol ext4_initxattrs static
jbd2: fix hung processes in jbd2_journal_lock_updates()
ext4: reserve new feature flag codepoints
ext4: Report max_batch_time option correctly
ext4: add missing ext4_resize_end on error paths
ext4: let ext4_group_add() use common code
ext4: let ext4_group_extend() use common code
ext4: add new online resize interface
ext4: add a new function which adds a flex group to a fs
ext4: add a new function which allocates bitmaps and inode tables
ext4: pass verify_reserved_gdb() the number of group decriptors
ext4: add a function which updates the super block during online resizing
ext4: add a function which sets up a block group descriptors of a flex bg
ext4: add a function which sets up group blocks of a flex bg
ext4: add a structure which will be used by 64bit-resize interface
ext4: add a function which adds a new group descriptors to a fs
ext4: add a function which extends a group without checking parameters
ext4: use proper little-endian bitops
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
fs/9p: iattr_valid flags are kernel internal flags map them to 9p values.
fs/9p: We should not allocate a new inode when creating hardlines.
fs/9p: v9fs_stat2inode should update suid/sgid bits.
9p: Reduce object size with CONFIG_NET_9P_DEBUG
fs/9p: check schedule_timeout_interruptible return value
Fix up trivial conflicts in fs/9p/{vfs_inode.c,vfs_inode_dotl.c} due to
debug messages having changed to use p9_debug() on one hand, and the
changes for umode_t on the other.
* 'nfs-for-3.3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFSv4: Change the default setting of the nfs4_disable_idmapping parameter
NFSv4: Save the owner/group name string when doing open
NFS: Remove pNFS bloat from the generic write path
pnfs-obj: Must return layout on IO error
pnfs-obj: pNFS errors are communicated on iodata->pnfs_error
NFS: Cache state owners after files are closed
NFS: Clean up nfs4_find_state_owners_locked()
NFSv4: include bitmap in nfsv4 get acl data
nfs: fix a minor do_div portability issue
NFSv4.1: cleanup comment and debug printk
NFSv4.1: change nfs4_free_slot parameters for dynamic slots
NFSv4.1: cleanup init and reset of session slot tables
NFSv4.1: fix backchannel slotid off-by-one bug
nfs: fix regression in handling of context= option in NFSv4
NFS - fix recent breakage to NFS error handling.
NFS: Retry mounting NFSROOT
SUNRPC: Clean up the RPCSEC_GSS service ticket requests
* 'linux-next' of git://git.infradead.org/ubifs-2.6:
UBI: fix use-after-free on error path
UBI: fix missing scrub when there is a bit-flip
UBIFS: Use kmemdup rather than duplicating its implementation
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)
iEYEABECAAYFAk8Mq/MACgkQdwG7hYl686PeFACfZCgbdDWD9A/JL+i1RMfExVu6
Pi0An3Hmc3PTCp0yQ21KtcKhpF9CAMEu
=NfuL
-----END PGP SIGNATURE-----
Merge tag 'for-linus-3.3' of git://git.infradead.org/mtd-2.6
MTD pull for 3.3
* tag 'for-linus-3.3' of git://git.infradead.org/mtd-2.6: (113 commits)
mtd: Fix dependency for MTD_DOC200x
mtd: do not use mtd->block_markbad directly
logfs: do not use 'mtd->block_isbad' directly
mtd: introduce mtd_can_have_bb helper
mtd: do not use mtd->suspend and mtd->resume directly
mtd: do not use mtd->lock, unlock and is_locked directly
mtd: do not use mtd->sync directly
mtd: harmonize mtd_writev usage
mtd: do not use mtd->lock_user_prot_reg directly
mtd: mtd->write_user_prot_reg directly
mtd: do not use mtd->read_*_prot_reg directly
mtd: do not use mtd->get_*_prot_info directly
mtd: do not use mtd->read_oob directly
mtd: mtdoops: do not use mtd->panic_write directly
romfs: do not use mtd->get_unmapped_area directly
mtd: do not use mtd->get_unmapped_area directly
mtd: do use mtd->point directly
mtd: introduce mtd_has_oob helper
mtd: mtdcore: export symbols cleanup
mtd: clean-up the default_mtd_writev function
...
Fix up trivial edit/remove conflict in drivers/staging/spectra/lld_mtd.c
Two (or more) concurrent calls of shrink_dcache_parent() on the same dentry may
cause shrink_dcache_parent() to loop forever.
Here's what appears to happen:
1 - CPU0: select_parent(P) finds C and puts it on dispose list, returns 1
2 - CPU1: select_parent(P) locks P->d_lock
3 - CPU0: shrink_dentry_list() locks C->d_lock
dentry_kill(C) tries to lock P->d_lock but fails, unlocks C->d_lock
4 - CPU1: select_parent(P) locks C->d_lock,
moves C from dispose list being processed on CPU0 to the new
dispose list, returns 1
5 - CPU0: shrink_dentry_list() finds dispose list empty, returns
6 - Goto 2 with CPU0 and CPU1 switched
Basically select_parent() steals the dentry from shrink_dentry_list() and thinks
it found a new one, causing shrink_dentry_list() to think it's making progress
and loop over and over.
One way to trigger this is to make udev calls stat() on the sysfs file while it
is going away.
Having a file in /lib/udev/rules.d/ with only this one rule seems to the trick:
ATTR{vendor}=="0x8086", ATTR{device}=="0x10ca", ENV{PCI_SLOT_NAME}="%k", ENV{MATCHADDR}="$attr{address}", RUN+="/bin/true"
Then execute the following loop:
while true; do
echo -bond0 > /sys/class/net/bonding_masters
echo +bond0 > /sys/class/net/bonding_masters
echo -bond1 > /sys/class/net/bonding_masters
echo +bond1 > /sys/class/net/bonding_masters
done
One fix would be to check all callers and prevent concurrent calls to
shrink_dcache_parent(). But I think a better solution is to stop the
stealing behavior.
This patch adds a new dentry flag that is set when the dentry is added to the
dispose list. The flag is cleared in dentry_lru_del() in case the dentry gets a
new reference just before being pruned.
If the dentry has this flag, select_parent() will skip it and let
shrink_dentry_list() retry pruning it. With select_parent() skipping those
dentries there will not be the appearance of progress (new dentries found) when
there is none, hence shrink_dcache_parent() will not loop forever.
Set the flag is also set in prune_dcache_sb() for consistency as suggested by
Linus.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Commit 503358ae01 ("ext4: avoid divide by
zero when trying to mount a corrupted file system") fixes CVE-2009-4307
by performing a sanity check on s_log_groups_per_flex, since it can be
set to a bogus value by an attacker.
sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
groups_per_flex = 1 << sbi->s_log_groups_per_flex;
if (groups_per_flex < 2) { ... }
This patch fixes two potential issues in the previous commit.
1) The sanity check might only work on architectures like PowerPC.
On x86, 5 bits are used for the shifting amount. That means, given a
large s_log_groups_per_flex value like 36, groups_per_flex = 1 << 36
is essentially 1 << 4 = 16, rather than 0. This will bypass the check,
leaving s_log_groups_per_flex and groups_per_flex inconsistent.
2) The sanity check relies on undefined behavior, i.e., oversized shift.
A standard-confirming C compiler could rewrite the check in unexpected
ways. Consider the following equivalent form, assuming groups_per_flex
is unsigned for simplicity.
groups_per_flex = 1 << sbi->s_log_groups_per_flex;
if (groups_per_flex == 0 || groups_per_flex == 1) {
We compile the code snippet using Clang 3.0 and GCC 4.6. Clang will
completely optimize away the check groups_per_flex == 0, leaving the
patched code as vulnerable as the original. GCC keeps the check, but
there is no guarantee that future versions will do the same.
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
lookup should fail with ENOMEM, not silently make dentry negative.
Switched to saner calling conventions, while we are at it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: new helper - d_make_root()
dcache: use a dispose list in select_parent
ceph: d_alloc_root() may fail
ext4: fix failure exits
isofs: inode leak on mount failure
select_parent currently abuses the dentry cache LRU to provide
cleanup features for child dentries that need to be freed. It moves
them to the tail of the LRU, then tells shrink_dcache_parent() to
calls __shrink_dcache_sb to unconditionally move them to a dispose
list (as DCACHE_REFERENCED is ignored). __shrink_dcache_sb() has to
relock the dentries to move them off the LRU onto the dispose list,
but otherwise does not touch the dentries that select_parent() moved
to the tail of the LRU. It then passses the dispose list to
shrink_dentry_list() which tries to free the dentries.
IOWs, the use of __shrink_dcache_sb() is superfluous - we can build
exactly the same list of dentries for disposal directly in
select_parent() and call shrink_dentry_list() instead of calling
__shrink_dcache_sb() to do that. This means that we avoid long holds
on the lru lock walking the LRU moving dentries to the dispose list
We also avoid the need to relock each dentry just to move it off the
LRU, reducing the numebr of times we lock each dentry to dispose of
them in shrink_dcache_parent() from 3 to 2 times.
Further, we remove one of the two callers of __shrink_dcache_sb().
This also means that __shrink_dcache_sb can be moved into back into
prune_dcache_sb() and we no longer have to handle referenced
dentries conditionally, simplifying the code.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
a) leaking root dentry is bad
b) in case of failed ext4_mb_init() we don't want to do ext4_mb_release()
c) OTOH, in the same case we *do* want ext4_ext_release()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
ext2/3/4: delete unneeded includes of module.h
ext{3,4}: Fix potential race when setversion ioctl updates inode
udf: Mark LVID buffer as uptodate before marking it dirty
ext3: Don't warn from writepage when readonly inode is spotted after error
jbd: Remove j_barrier mutex
reiserfs: Force inode evictions before umount to avoid crash
reiserfs: Fix quota mount option parsing
udf: Treat symlink component of type 2 as /
udf: Fix deadlock when converting file from in-ICB one to normal one
udf: Cleanup calling convention of inode_getblk()
ext2: Fix error handling on inode bitmap corruption
ext3: Fix error handling on inode bitmap corruption
ext3: replace ll_rw_block with other functions
ext3: NULL dereference in ext3_evict_inode()
jbd: clear revoked flag on buffers before a new transaction started
ext3: call ext3_mark_recovery_complete() when recovery is really needed
* 'for-linus' of git://git.open-osd.org/linux-open-osd:
ore: Must support none-PAGE-aligned IO
ore: fix BUG_ON, too few sgs when reading
ore: Fix crash in case of an IO error.
ore: FIX breakage when MISC_FILESYSTEMS is not set
Now that the use of numeric uids/gids is officially sanctioned in
RFC3530bis, it is time to change the default here to 'enabled'.
By doing so, we ensure that NFSv4 copies the behaviour of NFSv3 when we're
using the default AUTH_SYS authentication (i.e. when the client uses the
numeric uids/gids as authentication tokens), so that when new files are
created, they will appear to have the correct user/group.
It also fixes a number of backward compatibility issues when migrating
from NFSv3 to NFSv4 on a platform where the server uses different uid/gid
mappings than the client.
Note also that this setting has been successfully tested against servers
that do not support numeric uids/gids at several Connectathon/Bakeathon
events at this point, and the fall back to using string names/groups has
been shown to work well in all those test cases.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Instead, use the new 'mtd_can_have_bb()', or just rely on 'mtd_block_markbad()'
return code, which will be -EOPNOTSUPP if bad blocks are not supported.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Instead, use the new 'mtd_can_have_bb()' helper.
Cc: Jörn Engel <joern@logfs.org>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch teaches 'mtd_sync()' to do nothing when the MTD driver does
not have the '->sync()' method, which allows us to remove all direct
'mtd->sync' accesses.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This patch makes the 'mtd_writev()' function more usable and logical. We first
teach it to fall-back to the 'default_mtd_writev()' function if the MTD driver
does not define its own '->writev()' method. Then we make block2mtd and JFFS2
just 'mtd_writev()' instead of 'default_mtd_writev()' function. This means we
can now stop exporting 'default_mtd_writev()' and instead, export
'mtd_writev()'. This is much cleaner and more logical, as well as allows us to
get read of another direct 'mtd->writev' access in JFFS2.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Remove direct usage of mtd->get_unmapped_area. Instead, just call
'mtd_get_unmapped_area()' which will return -EOPNOTSUPP if the function
is not implemented, and then test for this code.
We also translate -EOPNOTSUPP to -ENOSYS because this return code is
probably part of the kernel ABI which we do not want to break.
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Remove direct usage of the "mtd->point" function pointer. Instead,
test the mtd_point() return code for '-EOPNOTSUPP'.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Instead, use 'default_mtd_writev()' function which MTD provides.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
