- 11 Sep, 2013 40 commits
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Davidlohr Bueso authored
As suggested by Andrew, add a generic initial locking scheme used throughout all sysv ipc mechanisms. Documenting the ids rwsem, how rcu can be enough to do the initial checks and when to actually acquire the kern_ipc_perm.lock spinlock. I found that adding it to util.c was generic enough. Signed-off-by:
Davidlohr Bueso <davidlohr.bueso@hp.com> Tested-by:
Sedat Dilek <sedat.dilek@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Davidlohr Bueso authored
There is only one user left, drop this function and just call ipc_unlock_object() and rcu_read_unlock(). Signed-off-by:
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Davidlohr Bueso authored
Since in some situations the lock can be shared for readers, we shouldn't be calling it a mutex, rename it to rwsem. Signed-off-by:
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Davidlohr Bueso authored
Similar to other system calls, acquire the kern_ipc_perm lock after doing the initial permission and security checks. [sasha.levin@oracle.com: dont leave do_shmat with rcu lock held] Signed-off-by:
Sasha Levin <sasha.levin@oracle.com> Signed-off-by:
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Davidlohr Bueso authored
Clean up some of the messy do_shmat() spaghetti code, getting rid of out_free and out_put_dentry labels. This makes shortening the critical region of this function in the next patch a little easier to do and read. Signed-off-by:
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Davidlohr Bueso authored
With the *_INFO, *_STAT, IPC_RMID and IPC_SET commands already optimized, deal with the remaining SHM_LOCK and SHM_UNLOCK commands. Take the shm_perm lock after doing the initial auditing and security checks. The rest of the logic remains unchanged. Signed-off-by:
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Davidlohr Bueso authored
While the INFO cmd doesn't take the ipc lock, the STAT commands do acquire it unnecessarily. We can do the permissions and security checks only holding the rcu lock. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
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Davidlohr Bueso authored
Similar to semctl and msgctl, when calling msgctl, the *_INFO and *_STAT commands can be performed without acquiring the ipc object. Add a shmctl_nolock() function and move the logic of *_INFO and *_STAT out of msgctl(). Since we are just moving functionality, this change still takes the lock and it will be properly lockless in the next patch. Signed-off-by:
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Davidlohr Bueso authored
Now that sem, msgque and shm, through *_down(), all use the lockless variant of ipcctl_pre_down(), go ahead and delete it. [akpm@linux-foundation.org: fix function name in kerneldoc, cleanups] Signed-off-by:
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Davidlohr Bueso authored
Instead of holding the ipc lock for the entire function, use the ipcctl_pre_down_nolock and only acquire the lock for specific commands: RMID and SET. Signed-off-by:
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Davidlohr Bueso authored
This is the third and final patchset that deals with reducing the amount of contention we impose on the ipc lock (kern_ipc_perm.lock). These changes mostly deal with shared memory, previous work has already been done for semaphores and message queues: http://lkml.org/lkml/2013/3/20/546 (sems) http://lkml.org/lkml/2013/5/15/584 (mqueues) With these patches applied, a custom shm microbenchmark stressing shmctl doing IPC_STAT with 4 threads a million times, reduces the execution time by 50%. A similar run, this time with IPC_SET, reduces the execution time from 3 mins and 35 secs to 27 seconds. Patches 1-8: replaces blindly taking the ipc lock for a smarter combination of rcu and ipc_obtain_object, only acquiring the spinlock when updating. Patch 9: renames the ids rw_mutex to rwsem, which is what it already was. Patch 10: is a trivial mqueue leftover cleanup Patch 11: adds a brief lock scheme description, requested by Andrew. This patch: Add shm_obtain_object() and shm_obtain_object_check(), which will allow us to get the ipc object without acquiring the lock. Just as with other forms of ipc, these functions are basically wrappers around ipc_obtain_object*(). Signed-off-by:
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Rob Landley authored
Command line option rootfstype=ramfs to obtain old initramfs behavior, and use ramfs instead of tmpfs for stub when root= defined (for cosmetic reasons). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
Rob Landley <rob@landley.net> Cc: Jeff Layton <jlayton@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Stephen Warren <swarren@nvidia.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jim Cromie <jim.cromie@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by:
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Rob Landley authored
Conditionally call the appropriate fs_init function and fill_super functions. Add a use once guard to shmem_init() to simply succeed on a second call. (Note that IS_ENABLED() is a compile time constant so dead code elimination removes unused function calls when CONFIG_TMPFS is disabled.) Signed-off-by:
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Rob Landley authored
When the rootfs code was a wrapper around ramfs, having them in the same file made sense. Now that it can wrap another filesystem type, move it in with the init code instead. This also allows a subsequent patch to access rootfstype= command line arg. Signed-off-by:
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Rob Landley authored
Even though ramfs hasn't got a backing device, commit e0bf68dd ("mm: bdi init hooks") added one anyway, and put the initialization in init_rootfs() since that's the first user, leaving it out of init_ramfs() to avoid duplication. But initmpfs uses init_tmpfs() instead, so move the init into the filesystem's init function, add a "once" guard to prevent duplicate initialization, and call the filesystem init from rootfs init. This goes part of the way to allowing ramfs to be built as a module. [akpm@linux-foundation.org; using bit 1 was odd] Signed-off-by:
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Rob Landley authored
Mounting MS_NOUSER prevents --bind mounts from rootfs. Prevent new rootfs mounts with a different mechanism that doesn't affect bind mounts. Signed-off-by:
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Jan Kara authored
With users of radix_tree_preload() run from interrupt (block/blk-ioc.c is one such possible user), the following race can happen: radix_tree_preload() ... radix_tree_insert() radix_tree_node_alloc() if (rtp->nr) { ret = rtp->nodes[rtp->nr - 1]; <interrupt> ... radix_tree_preload() ... radix_tree_insert() radix_tree_node_alloc() if (rtp->nr) { ret = rtp->nodes[rtp->nr - 1]; And we give out one radix tree node twice. That clearly results in radix tree corruption with different results (usually OOPS) depending on which two users of radix tree race. We fix the problem by making radix_tree_node_alloc() always allocate fresh radix tree nodes when in interrupt. Using preloading when in interrupt doesn't make sense since all the allocations have to be atomic anyway and we cannot steal nodes from process-context users because some users rely on radix_tree_insert() succeeding after radix_tree_preload(). in_interrupt() check is somewhat ugly but we cannot simply key off passed gfp_mask as that is acquired from root_gfp_mask() and thus the same for all preload users. Another part of the fix is to avoid node preallocation in radix_tree_preload() when passed gfp_mask doesn't allow waiting. Again, preallocation in such case doesn't make sense and when preallocation would happen in interrupt we could possibly leak some allocated nodes. However, some users of radix_tree_preload() require following radix_tree_insert() to succeed. To avoid unexpected effects for these users, radix_tree_preload() only warns if passed gfp mask doesn't allow waiting and we provide a new function radix_tree_maybe_preload() for those users which get different gfp mask from different call sites and which are prepared to handle radix_tree_insert() failure. Signed-off-by:Jan Kara <jack@suse.cz> Cc: Jens Axboe <jaxboe@fusionio.com> Signed-off-by:
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Jingoo Han authored
The driver core clears the driver data to NULL after device_release or on probe failure. Thus, it is not needed to manually clear the device driver data to NULL. Signed-off-by:
Jingoo Han <jg1.han@samsung.com> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Greg KH <greg@kroah.com> Acked-by:
Shawn Guo <shawn.guo@linaro.org> Signed-off-by:
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Jingoo Han authored
The usage of strict_strtol() is not preferred, because strict_strtol() is obsolete. Thus, kstrtol() should be used. Signed-off-by:
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Maxim Levitsky authored
Based partially on MS standard spec quotes from Alex Dubov. As any code that works with user data this driver isn't recommended to use to write cards that contain valuable data. It tries its best though to avoid data corruption and possible damage to the card. Tested on MS DUO 64 MB card on Ricoh R592 card reader. Signed-off-by:
Maxim Levitsky <maximlevitsky@gmail.com> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alex Dubov <oakad@yahoo.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by:
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Jingoo Han authored
The driver core clears the driver data to NULL after device_release or on probe failure. Thus, it is not needed to manually clear the device driver data to NULL. Signed-off-by:
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Jingoo Han authored
The driver core clears the driver data to NULL after device_release or on probe failure. Thus, it is not needed to manually clear the device driver data to NULL. Signed-off-by:
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Joe Perches authored
Fix thinkos where pkt_<level> needs a valid pktcdvd_device * and the pointer is known to be NULL. Signed-off-by:
Joe Perches <joe@perches.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> (go smatch!) Signed-off-by:
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Joe Perches authored
Allow the device name to be emitted with pkt_err when logging the sense data. Signed-off-by:
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Joe Perches authored
Add a new pkt_info macro to prefix the name to the logging output. Signed-off-by:
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Joe Perches authored
Add a new pkt_notice macro to prefix the name to the logging output. Signed-off-by:
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Joe Perches authored
Add a new pkt_err macro to prefix the name to the logging output. Convert pr_err where there is a non-null struct pktcdvd_device. Includes improvements from Andy Shevchenko. Signed-off-by:
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Joe Perches authored
Add pd->name to output for these debugging messages. Remove normally compiled out pkt_dbg(2, ...) function entry tracing equivalents as it's better done via the function tracer. Signed-off-by:
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Joe Perches authored
Use the more common pkt_dbg(level, fmt, ...) form. These messages are emitted at KERN_NOTICE. Always emit function name with pkt_dbg(2, ...) uses and remove the sometimes abbreviated embedded function name. This form always verifies the format and arguments. Signed-off-by:
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Joe Perches authored
Use a more current logging style and add messages levels to the logging messages. Simplify pkt_dump_sense by using %*ph and adding a simple function to emit the sense string. Includes improvements from Andy Shevchenko and Dan Carpenter. Signed-off-by:
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Joe Perches authored
Macros should be converted to functions where feasible to verify arguments and the like. Signed-off-by:
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Kees Cook authored
Since the panic handlers may produce additional information (via printk) for the kernel log, it should be reported as part of the panic output saved by kmsg_dump(). Without this re-ordering, nothing that adds information to a panic will show up in pstore's view when kmsg_dump runs, and is therefore not visible to crash reporting tools that examine pstore output. Signed-off-by:
Kees Cook <keescook@chromium.org> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Acked-by:
Tony Luck <tony.luck@intel.com> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Vikram Mulukutla <markivx@codeaurora.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by:
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Dan Carpenter authored
It seems pretty unlikely that AFFS supports files over 4GB but we may as well leave use loff_t just for cleanness sake instead of truncating it to 32 bits. Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Cc: Marco Stornelli <marco.stornelli@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Ed Cashin authored
When the example udev rules in the documentation are used without modification, warnings like the one shown below appear in the system logs: /var/log/messages:Aug 22 11:09:11 kung udevd[445]: NAME="%k" \ is superfluous and breaks kernel supplied names, please remove \ it from /etc/udev/rules.d/60-aoe.rules:26 Removing the term does not cause any problems with the creation of the special character and block device nodes. Signed-off-by:Ed Cashin <ecashin@coraid.com> Signed-off-by:
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Ed Cashin authored
If the system has trouble allocating memory for the creation of the aoe debugfs directory or of a file inside it, the debugfs member of an aoedev can be NULL. Do not treat a NULL debugfs pointer as a BUG on aoedev shutdown, avoiding the user impact of an unecessary panic. Signed-off-by:
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Andy Shevchenko authored
This patch fixes following compiler warnings: drivers/block/aoe/aoecmd.c: In function `aoecmd_ata_rw': drivers/block/aoe/aoecmd.c:383:17: warning: variable `t' set but not used [-Wunused-but-set-variable] struct aoetgt *t; ^ drivers/block/aoe/aoecmd.c: In function `resend': drivers/block/aoe/aoecmd.c:488:21: warning: variable `ah' set but not used [-Wunused-but-set-variable] struct aoe_atahdr *ah; ^ Signed-off-by:Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Ed Cashin <ecashin@coraid.com> Signed-off-by:
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Andy Shevchenko authored
In the kernel we have a nice helper that may be used here. This patch substitutes the custom implementation by the native function call. Signed-off-by:
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Ed Cashin authored
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Ed Cashin authored
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Ed Cashin authored
This information is presented in a compact format that has evolved for easy routine scanning by expert humans, mostly developers and support technicians helping to troubleshoot or test AoE-based systems. Signed-off-by:
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