summaryrefslogtreecommitdiffstats
path: root/lib/idr.c
Commit message (Collapse)AuthorAgeFilesLines
* Merge tag 'module-for-3.4' of ↵Linus Torvalds2012-03-241-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull cleanup of fs/ and lib/ users of module.h from Paul Gortmaker: "Fix up files in fs/ and lib/ dirs to only use module.h if they really need it. These are trivial in scope vs the work done previously. We now have things where any few remaining cleanups can be farmed out to arch or subsystem maintainers, and I have done so when possible. What is remaining here represents the bits that don't clearly lie within a single arch/subsystem boundary, like the fs dir and the lib dir. Some duplicate includes arising from overlapping fixes from independent subsystem maintainer submissions are also quashed." Fix up trivial conflicts due to clashes with other include file cleanups (including some due to the previous bug.h cleanup pull). * tag 'module-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: lib: reduce the use of module.h wherever possible fs: reduce the use of module.h wherever possible includecheck: delete any duplicate instances of module.h
| * lib: reduce the use of module.h wherever possiblePaul Gortmaker2012-03-071-1/+1
| | | | | | | | | | | | | | | | | | | | For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* | idr: make idr_get_next() good for rcu_read_lock()Hugh Dickins2012-03-211-3/+5
|/ | | | | | | | | | | | | | | Make one small adjustment to idr_get_next(): take the height from the top layer (stable under RCU) instead of from the root (unprotected by RCU), as idr_find() does: so that it can be used with RCU locking. Copied comment on RCU locking from idr_find(). Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ida: make ida_simple_get/put() IRQ safeTejun Heo2011-11-021-4/+7
| | | | | | | | | | | It's often convenient to be able to release resource from IRQ context. Make ida_simple_*() use irqsave/restore spin ops so that they are IRQ safe. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/idr.c: fix comment for ida_get_new_above()Wang Sheng-Hui2011-10-311-2/+2
| | | | | | Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'master' into for-nextJiri Kosina2011-09-151-0/+67
|\ | | | | | | | | Fast-forward merge with Linus to be able to merge patches based on more recent version of the tree.
| * ida: simplified functions for id allocationRusty Russell2011-08-031-0/+67
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current hyper-optimized functions are overkill if you simply want to allocate an id for a device. Create versions which use an internal lock. In followup patches, numerous drivers are converted to use this interface. Thanks to Tejun for feedback. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Fix kernel-doc comment typo '@id'Paul Bolle2011-08-041-1/+1
|/ | | | | Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* docbook: add idr/ida to kernel-api docbookRandy Dunlap2010-10-261-24/+25
| | | | | | | | | | | Add idr/ida to kernel-api docbook. Fix typos and kernel-doc notation. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Naohiro Aota <naota@elisp.net> Cc: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idr: fix idr_pre_get() locking descriptionNaohiro Aota2010-10-261-11/+13
| | | | | | | | | | | | | Despite the idr_pre_get() kernel-doc, there are some cases where you can call idr_pre_get() from within locked regions. Add a description for such cases. See also: http://lkml.org/lkml/2010/9/16/462 [akpm@linux-foundation.org: cleanups, grammatical fixes] Signed-off-by: Naohiro Aota <naota@elisp.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idr: describe how nextidp works in idr_get_next().Naohiro Aota2010-08-311-1/+2
| | | | | | | | | It was unclear in original kernel-doc how nextidp worked in idr_get_next(). Let's describe it. Signed-off-by: Naohiro Aota <naota@elisp.net> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* idr: fix kernel-doc warnings.Naohiro Aota2010-08-311-5/+5
| | | | | | | | | | | | | | | | | | Fix the following kernel-doc warnings. % perl scripts/kernel-doc lib/idr.c > /dev/null Warning(lib/idr.c:300): No description found for parameter 'starting_id' Warning(lib/idr.c:300): Excess function parameter 'start_id' description in 'idr_get_new_above' Warning(lib/idr.c:485): No description found for parameter 'idp' Warning(lib/idr.c:596): No description found for parameter 'nextidp' Warning(lib/idr.c:596): Excess function parameter 'id' description in 'idr_get_next' Warning(lib/idr.c:774): No description found for parameter 'starting_id' Warning(lib/idr.c:774): Excess function parameter 'staring_id' description in 'ida_get_new_above' Warning(lib/idr.c:918): No description found for parameter 'ida' Signed-off-by: Naohiro Aota <naota@elisp.net> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* idr: fix RCU lockdep splat in idr_get_next()Paul E. McKenney2010-06-231-2/+2
| | | | | | | | | Convert to rcu_dereference_raw() given that many callers may have many different locking models. Located-by: Miles Lane <miles.lane@gmail.com> Tested-by: Miles Lane <miles.lane@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
* idr: fix backtrack logic in idr_remove_allImre Deak2010-05-271-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently idr_remove_all will fail with a use after free error if idr::layers is bigger than 2, which on 32 bit systems corresponds to items more than 1024. This is due to stepping back too many levels during backtracking. For simplicity let's assume that IDR_BITS=1 -> we have 2 nodes at each level below the root node and each leaf node stores two IDs. (In reality for 32 bit systems IDR_BITS=5, with 32 nodes at each sub-root level and 32 IDs in each leaf node). The sequence of freeing the nodes at the moment is as follows: layer 1 -> a(7) 2 -> b(3) c(5) 3 -> d(1) e(2) f(4) g(6) Until step 4 things go fine, but then node c is freed, whereas node g should be freed first. Since node c contains the pointer to node g we'll have a use after free error at step 6. How many levels we step back after visiting the leaf nodes is currently determined by the msb of the id we are currently visiting: Step 1. node d with IDs 0,1 is freed, current ID is advanced to 2. msb of the current ID bit 1. This means we need to step back 1 level to node b and take the next sibling, node e. 2-3. node e with IDs 2,3 is freed, current ID is 4, msb is bit 2. This means we need to step back 2 levels to node a, freeing node b on the way. 4-5. node f with IDs 4,5 is freed, current ID is 6, msb is still bit 2. This means we again need to step back 2 levels to node a and free c on the way. 6. We should visit node g, but its pointer is not available as node c was freed. The fix changes how we determine the number of levels to step back. Instead of deducting this merely from the msb of the current ID, we should really check if advancing the ID causes an overflow to a bit position corresponding to a given layer. In the above example overflow from bit 0 to bit 1 should mean stepping back 1 level. Overflow from bit 1 to bit 2 should mean stepping back 2 levels and so on. The fix was tested with IDs up to 1 << 20, which corresponds to 4 layers on 32 bit systems. Signed-off-by: Imre Deak <imre.deak@nokia.com> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: Eric Paris <eparis@redhat.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: <stable@kernel.org> [2.6.34.1] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'master' of ↵David Woodhouse2010-03-261-4/+4
|\ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 Conflicts: drivers/mtd/nand/sh_flctl.c Maxim's patch to initialise sysfs attributes depends on the patch which actually adds sysfs_attr_init().
| * idr: Apply lockdep-based diagnostics to rcu_dereference() usesPaul E. McKenney2010-02-251-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because idr can be used with any of a number of locks or with any flavor of RCU, just disable the lockdep-based diagnostics. If idr needs diagnostics, the check expression will need to be passed into the relevant idr primitives as an additional argument. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1266887105-1528-11-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'master' of ↵David Woodhouse2010-02-261-1/+3
|\| | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 The SmartMedia FTL code depends on new kfifo bits from 2.6.33
| * idr: fix a critical misallocation bug, take#2Tejun Heo2010-02-221-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is retry of reverted 859ddf09743a8cc680af33f7259ccd0fd36bfe9d ("idr: fix a critical misallocation bug") which contained two bugs. * pa[idp->layers] should be cleared even if it's not used by sub_alloc() because it's used by mark idr_mark_full(). * The original condition check also assigned pa[l] to p which the new code didn't do thus leaving p pointing at the wrong layer. Both problems have been fixed and the idr code has received good amount testing using userland testing setup where simple bitmap allocator is run parallel to verify the result of idr allocation. The bug this patch fixes is caused by sub_alloc() optimization path bypassing out-of-room condition check and restarting allocation loop with starting value higher than maximum allowed value. For detailed description, please read commit message of 859ddf09. Signed-off-by: Tejun Heo <tj@kernel.org> Based-on-patch-from: Eric Paris <eparis@redhat.com> Reported-by: Eric Paris <eparis@redhat.com> Tested-by: Stefan Lippers-Hollmann <s.l-h@gmx.de> Tested-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * idr: revert misallocation bug fixTejun Heo2010-02-041-3/+4
| | | | | | | | | | | | | | | | | | | | | | Commit 859ddf09743a8cc680af33f7259ccd0fd36bfe9d tried to fix misallocation bug but broke full bit marking by not clearing pa[idp->layers] and also is causing X failures due to lookup failure in drm code. The cause of the latter hasn't been found yet. Revert the fix for now. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * idr: fix a critical misallocation bugTejun Heo2010-02-021-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Eric Paris located a bug in idr. With IDR_BITS of 6, it grows to three layers when id 4096 is first allocated. When that happens, idr wraps incorrectly and searches the idr array ignoring the high bits. The following test code from Eric demonstrates the bug nicely. #include <linux/idr.h> #include <linux/kernel.h> #include <linux/module.h> static DEFINE_IDR(test_idr); int init_module(void) { int ret, forty95, forty96; void *addr; /* add 2 entries both with 4095 as the start address */ again1: if (!idr_pre_get(&test_idr, GFP_KERNEL)) return -ENOMEM; ret = idr_get_new_above(&test_idr, (void *)4095, 4095, &forty95); if (ret) { if (ret == -EAGAIN) goto again1; return ret; } if (forty95 != 4095) printk(KERN_ERR "hmmm, forty95=%d\n", forty95); again2: if (!idr_pre_get(&test_idr, GFP_KERNEL)) return -ENOMEM; ret = idr_get_new_above(&test_idr, (void *)4096, 4095, &forty96); if (ret) { if (ret == -EAGAIN) goto again2; return ret; } if (forty96 != 4096) printk(KERN_ERR "hmmm, forty96=%d\n", forty96); /* try to find the 2 entries, noticing that 4096 broke */ addr = idr_find(&test_idr, forty95); if ((int)addr != forty95) printk(KERN_ERR "hmmm, after find forty95=%d addr=%d\n", forty95, (int)addr); addr = idr_find(&test_idr, forty96); if ((int)addr != forty96) printk(KERN_ERR "hmmm, after find forty96=%d addr=%d\n", forty96, (int)addr); /* really weird, the entry which should be at 4096 is actually at 0!! */ addr = idr_find(&test_idr, 0); if ((int)addr) printk(KERN_ERR "found an entry at id=0 for addr=%d\n", (int)addr); idr_remove(&test_idr, forty95); idr_remove(&test_idr, forty96); return 0; } void cleanup_module(void) { } MODULE_AUTHOR("Eric Paris <eparis@redhat.com>"); MODULE_DESCRIPTION("Simple idr test"); MODULE_LICENSE("GPL"); This happens because when sub_alloc() back tracks it doesn't always do it step-by-step while the over-the-limit detection assumes step-by-step backtracking. The logic in sub_alloc() looks like the following. restart: clear pa[top level + 1] for end cond detection l = top level while (true) { search for empty slot at this level if (not found) { push id to the next possible value l++ A: if (pa[l] is clear) failed, return asking caller to grow the tree if (going up 1 level gives more slots to search) continue the while loop above with the incremented l else C: goto restart } adjust id accordingly to the found slot if (l == 0) return found id; create lower level if not there yet record pa[l] and l-- } Test A is the fail exit condition but this assumes that failure is propagated upwared one level at a time but the B optimization path breaks the assumption and restarts the whole thing with a start value which is above the possible limit with the current layers. sub_alloc() assumes the start id value is inside the limit when called and test A is the only exit condition check, so it ends up searching for empty slot while ignoring high set bit. So, for 4095->4096 test, level0 search fails but pa[1] contains a valid pointer. However, going up 1 level wouldn't give any more empty slot so it takes C and when the whole thing restarts nobody notices the high bit set beyond the top level. This patch fixes the bug by changing the fail exit condition check to full id limit check. Based-on-patch-from: Eric Paris <eparis@redhat.com> Reported-by: Eric Paris <eparis@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | idr: export idr_get_next()Ben Hutchings2010-02-251-1/+1
|/ | | | | | | | | | idr_get_next() was accidentally not exported when added. It is about to be used by mtdcore, which may be built as a module. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* tree-wide: fix some typos and punctuation in commentsThadeu Lima de Souza Cascardo2009-12-041-2/+2
| | | | | | | fix some typos and punctuation in comments Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* cgroup: CSS ID supportKAMEZAWA Hiroyuki2009-04-021-0/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch for Per-CSS(Cgroup Subsys State) ID and private hierarchy code. This patch attaches unique ID to each css and provides following. - css_lookup(subsys, id) returns pointer to struct cgroup_subysys_state of id. - css_get_next(subsys, id, rootid, depth, foundid) returns the next css under "root" by scanning When cgroup_subsys->use_id is set, an id for css is maintained. The cgroup framework only parepares - css_id of root css for subsys - id is automatically attached at creation of css. - id is *not* freed automatically. Because the cgroup framework don't know lifetime of cgroup_subsys_state. free_css_id() function is provided. This must be called by subsys. There are several reasons to develop this. - Saving space .... For example, memcg's swap_cgroup is array of pointers to cgroup. But it is not necessary to be very fast. By replacing pointers(8bytes per ent) to ID (2byes per ent), we can reduce much amount of memory usage. - Scanning without lock. CSS_ID provides "scan id under this ROOT" function. By this, scanning css under root can be written without locks. ex) do { rcu_read_lock(); next = cgroup_get_next(subsys, id, root, &found); /* check sanity of next here */ css_tryget(); rcu_read_unlock(); id = found + 1 } while(...) Characteristics: - Each css has unique ID under subsys. - Lifetime of ID is controlled by subsys. - css ID contains "ID" and "Depth in hierarchy" and stack of hierarchy - Allowed ID is 1-65535, ID 0 is UNUSED ID. Design Choices: - scan-by-ID v.s. scan-by-tree-walk. As /proc's pid scan does, scan-by-ID is robust when scanning is done by following kind of routine. scan -> rest a while(release a lock) -> conitunue from interrupted memcg's hierarchical reclaim does this. - When subsys->use_id is set, # of css in the system is limited to 65535. [bharata@linux.vnet.ibm.com: remove rcu_read_lock() from css_get_next()] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idr: make idr_remove_all() do removal -before- free_layer()Paul E. McKenney2009-03-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | Fix a problem in the IDR system, where an idr_remove_all() hands a data element to call_rcu() (via free_layer()) before making that data element inaccessible to new readers. This is very bad, and results in readers still having a reference to this data element at the end of the grace period. Tests on large machines that concurrently map and unmap user-space memory within the same multithreaded process result in crashes within about five minutes. Applying this patch increases the kernel's longevity to the three-to-eight-hour range. There appear to be other similar problems in idr_get_empty_slot() and sub_remove(), but I fixed the easy one in idr_remove_all() first. It is therefore no surprise that failures still occur. Located-by: Milton Miller II <miltonm@austin.ibm.com> Tested-by: Milton Miller II <miltonm@austin.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/idr.c: use kmem_cache_zalloc() for the idr_layer cacheAndrew Morton2009-01-151-8/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | David points out that the idr_remove_all() function returns unused slabs to the kmem cache, but needs to zero them first or else they will be uninitialized upon next use. This causes crashes which have been observed in the firewire subsystem. He fixed this by zeroing the object before freeing it in idr_remove_all(). But we agree that simply removing the constructor and zeroing the object at allocation time is simpler than relying upon slab constructor machinery and might even be faster. This problem was introduced by "idr: make idr_remove rcu-safe" (commit cf481c20c476ad2c0febdace9ce23f5a4db19582), which was first released in 2.6.27. There are no known codesites which trigger this bug in 2.6.27 or 2.6.28. The post-2.6.28 firewire changes are the only known triggerer. There might of course be not-yet-discovered triggerers in 2.6.27 and 2.6.28, and there might be out-of-tree triggerers which are added to those kernel versions. I'll let the -stable guys decide whether they want to backport this fix. Reported-by: David Moore <dcm@acm.org> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Paul E. McKenney <paulmck@us.ibm.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Kristian Hgsberg <krh@redhat.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idr: fix wrong kernel-docLi Zefan2009-01-151-2/+2
| | | | | | | | | idr_get_new_above() and ida_get_new_above() return an id in the range of @staring_id ... 0x7fffffff, not 0 ... 0x7fffffff. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/idr.c: Fix bug introduced by RCU fixManfred Spraul2008-12-101-1/+7
| | | | | | | | | | | | | | | | | | The last patch to lib/idr.c caused a bug if idr_get_new_above() was called on an empty idr. Usually, nodes stay on the same layer. New layers are added to the top of the tree. The exception is idr_get_new_above() on an empty tree: In this case, the new root node is first added on layer 0, then moved upwards. p->layer was not updated. As usual: You shall never rely on the source code comments, they will only mislead you. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/idr.c: fix rcu related race with idr_findManfred Spraul2008-12-011-2/+12
| | | | | | | | | | | | | | | | | | | 2nd part of the fixes needed for http://bugzilla.kernel.org/show_bug.cgi?id=11796. When the idr tree is either grown or shrunk, then the update to the number of layers and the top pointer were not atomic. This race caused crashes. The attached patch fixes that by replicating the layers counter in each layer, thus idr_find doesn't need idp->layers anymore. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Clement Calmels <cboulte@gmail.com> Cc: Nadia Derbey <Nadia.Derbey@bull.net> Cc: Pierre Peiffer <peifferp@gmail.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SL*B: drop kmem cache argument from constructorAlexey Dobriyan2008-07-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Kmem cache passed to constructor is only needed for constructors that are themselves multiplexeres. Nobody uses this "feature", nor does anybody uses passed kmem cache in non-trivial way, so pass only pointer to object. Non-trivial places are: arch/powerpc/mm/init_64.c arch/powerpc/mm/hugetlbpage.c This is flag day, yes. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Christoph Lameter <cl@linux-foundation.org> Cc: Jon Tollefson <kniht@linux.vnet.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Matt Mackall <mpm@selenic.com> [akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c] [akpm@linux-foundation.org: fix mm/slab.c] [akpm@linux-foundation.org: fix ubifs] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idr: make idr_remove rcu-safeNadia Derbey2008-07-251-14/+43
| | | | | | | | | | | | | | Introduce the free_layer() routine: it is the one that actually frees memory after a grace period has elapsed. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Reviewed-by: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Jim Houston <jim.houston@comcast.net> Cc: Pierre Peiffer <peifferp@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idr: make idr_find rcu-safeNadia Derbey2008-07-251-5/+6
| | | | | | | | | | | | | | Make idr_find rcu-safe: it can now be called inside an rcu_read critical section. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Reviewed-by: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Jim Houston <jim.houston@comcast.net> Cc: Pierre Peiffer <peifferp@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idr: make idr_get_new* rcu-safeNadia Derbey2008-07-251-5/+9
| | | | | | | | | | | | | Make the idr_get_new* routines rcu-safe. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Reviewed-by: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Jim Houston <jim.houston@comcast.net> Cc: Pierre Peiffer <peifferp@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idr: error checking factorizationNadia Derbey2008-07-251-21/+9
| | | | | | | | | | | | | Do some code factorization in the return code analysis. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Jim Houston <jim.houston@comcast.net> Cc: Pierre Peiffer <peifferp@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idr: fix a printk callNadia Derbey2008-07-251-1/+2
| | | | | | | | | | | | | Fix the incomplete printk call. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Reviewed-by: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Jim Houston <jim.houston@comcast.net> Cc: Pierre Peiffer <peifferp@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idr: rename some of the idr APIs internal routinesNadia Derbey2008-07-251-15/+16
| | | | | | | | | | | | | | | | | | | This is a trivial patch that renames: . alloc_layer to get_from_free_list since it idr_pre_get that actually allocates memory. . free_layer to move_to_free_list since memory is not actually freed there. This makes things more clear for the next patches. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Reviewed-by: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Jim Houston <jim.houston@comcast.net> Cc: Pierre Peiffer <peifferp@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idr: fix idr_remove()Nadia Derbey2008-05-011-1/+1
| | | | | | | | | | | The return inside the loop makes us free only a single layer. Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Jim Houston <jim.houston@comcast.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idr: create idr_layer_cache at boot timeAkinobu Mita2008-04-291-6/+4
| | | | | | | | | | | | | | | Avoid a possible kmem_cache_create() failure by creating idr_layer_cache unconditionary at boot time rather than creating it on-demand when idr_init() is called the first time. This change also enables us to eliminate the check every time idr_init() is called. [akpm@linux-foundation.org: rename init_id_cache() to idr_init_cache()] [akpm@linux-foundation.org: fix alpha build] Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Slab API: remove useless ctor parameter and reorder parametersChristoph Lameter2007-10-171-2/+1
| | | | | | | | | | | | | | | | | | | | | Slab constructors currently have a flags parameter that is never used. And the order of the arguments is opposite to other slab functions. The object pointer is placed before the kmem_cache pointer. Convert ctor(void *object, struct kmem_cache *s, unsigned long flags) to ctor(struct kmem_cache *s, void *object) throughout the kernel [akpm@linux-foundation.org: coupla fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* more low-hanging fruits - kernel, fs, lib signednessAl Viro2007-10-141-1/+1
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* idr_remove_all: kill unused variableOleg Nesterov2007-07-311-2/+2
| | | | | | | | "error" is always equal to 0. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: Remove slab destructors from kmem_cache_create().Paul Mundt2007-07-201-1/+1
| | | | | | | | | | | | | | Slab destructors were no longer supported after Christoph's c59def9f222d44bb7e2f0a559f2906191a0862d7 change. They've been BUGs for both slab and slub, and slob never supported them either. This rips out support for the dtor pointer from kmem_cache_create() completely and fixes up every single callsite in the kernel (there were about 224, not including the slab allocator definitions themselves, or the documentation references). Signed-off-by: Paul Mundt <lethal@linux-sh.org>
* lib: add idr_remove_allKristian Hoegsberg2007-07-161-0/+47
| | | | | | | | | | | | | | | | Remove all ids from the given idr tree. idr_destroy() only frees up unused, cached idp_layers, but this function will remove all id mappings and leave all idp_layers unused. A typical clean-up sequence for objects stored in an idr tree, will use idr_for_each() to free all objects, if necessay, then idr_remove_all() to remove all ids, and idr_destroy() to free up the cached idr_layers. Signed-off-by: Kristian Hoegsberg <krh@redhat.com> Cc: Tejun Heo <htejun@gmail.com> Cc: Dave Airlie <airlied@linux.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib: add idr_for_each()Kristian Hoegsberg2007-07-161-0/+55
| | | | | | | | | | | | | | | | | | | | This patch adds an iterator function for the idr data structure. Compared to just iterating through the idr with an integer and idr_find, this iterator is (almost, but not quite) linear in the number of elements, as opposed to the number of integers in the range covered by the idr. This makes a difference for sparse idrs, but more importantly, it's a nicer way to iterate through the elements. The drm subsystem is moving to idr for tracking contexts and drawables, and with this change, we can use the idr exclusively for tracking these resources. [akpm@linux-foundation.org: fix comment] Signed-off-by: Kristian Hoegsberg <krh@redhat.com> Cc: Tejun Heo <htejun@gmail.com> Cc: Dave Airlie <airlied@linux.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ida: implement idr based id allocatorTejun Heo2007-07-111-0/+245
| | | | | | | | | | | | | | | | | | | Implement idr based id allocator. ida is used the same way idr is used but lacks id -> ptr translation and thus consumes much less memory. struct ida_bitmap is attached as leaf nodes to idr tree which is managed by the idr code. Each ida_bitmap is 128bytes long and contains slightly less than a thousand slots. ida is more aggressive with releasing extra resources acquired using ida_pre_get(). After every successful id allocation, ida frees one reserved idr_layer if possible. Reserved ida_bitmap is not freed automatically but only one ida_bitmap is reserved and it's almost always used right away. Under most circumstances, ida won't hold on to memory for too long which isn't actively used. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* idr: separate out idr_mark_full()Tejun Heo2007-07-111-25/+46
| | | | | | | | | | | | | | | | | Separate out idr_mark_full() from sub_alloc() and make marking the allocated slot full the responsibility of idr_get_new_above_int(). Allocation part of idr_get_new_above_int() is renamed to idr_get_empty_slot(). New idr_get_new_above_int() allocates a slot using the function, install the user pointer and marks it full using idr_mark_full(). This change doesn't introduce any behavior change. This will be used by ida. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* idr: fix obscure bug in allocation pathTejun Heo2007-07-111-2/+14
| | | | | | | | | | | | | | | | | | | | In sub_alloc(), when bitmap search fails, it goes up one level to continue search. This is done by updating the id cursor and searching the upper level again. If the cursor was at the end of the upper level, we need to go further than that. This wasn't implemented and when that happens the part of the cursor which indexes into the upper level wraps and sub_alloc() ends up searching the wrong bitmap. It allocates id which doesn't match the actual slot. This patch fixes this by restarting from the top if the search needs to go higher than one level. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* [PATCH] Numerous fixes to kernel-doc info in source files.Robert P. J. Day2007-02-111-2/+2
| | | | | | | | | | | | | | | A variety of (mostly) innocuous fixes to the embedded kernel-doc content in source files, including: * make multi-line initial descriptions single line * denote some function names, constants and structs as such * change erroneous opening '/*' to '/**' in a few places * reword some text for clarity Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] slab: remove kmem_cache_tChristoph Lameter2006-12-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace all uses of kmem_cache_t with struct kmem_cache. The patch was generated using the following script: #!/bin/sh # # Replace one string by another in all the kernel sources. # set -e for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do quilt add $file sed -e "1,\$s/$1/$2/g" $file >/tmp/$$ mv /tmp/$$ $file quilt refresh done The script was run like this sh replace kmem_cache_t "struct kmem_cache" Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Convert idr's internal locking to _irqsave variantRoland Dreier2006-07-141-6/+10
| | | | | | | | | | | | | | | | | | | | | | | Currently, the code in lib/idr.c uses a bare spin_lock(&idp->lock) to do internal locking. This is a nasty trap for code that might call idr functions from different contexts; for example, it seems perfectly reasonable to call idr_get_new() from process context and idr_remove() from interrupt context -- but with the current locking this would lead to a potential deadlock. The simplest fix for this is to just convert the idr locking to use spin_lock_irqsave(). In particular, this fixes a very complicated locking issue detected by lockdep, involving the ib_ipoib driver's priv->lock and dev->_xmit_lock, which get involved with the ib_sa module's query_idr.lock. Cc: Arjan van de Ven <arjan@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Zach Brown <zach.brown@oracle.com>, Signed-off-by: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] lib: add idr_replaceJeff Mahoney2006-06-261-0/+43
| | | | | | | | | | | | | This patch adds idr_replace() to replace an existing pointer in a single operation. Device-mapper will use this to update the pointer it stored against a given id. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-18 14:51:56 +0000