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2020-05-28radix-tree: Use local_lock for protectionSebastian Andrzej Siewior
The radix-tree and idr preload mechanisms use preempt_disable() to protect the complete operation between xxx_preload() and xxx_preload_end(). As the code inside the preempt disabled section acquires regular spinlocks, which are converted to 'sleeping' spinlocks on a PREEMPT_RT kernel and eventually calls into a memory allocator, this conflicts with the RT semantics. Convert it to a local_lock which allows RT kernels to substitute them with a real per CPU lock. On non RT kernels this maps to preempt_disable() as before, but provides also lockdep coverage of the critical region. No functional change. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/20200527201119.1692513-3-bigeasy@linutronix.de
2019-11-08Merge tag 'xarray-5.4' of git://git.infradead.org/users/willy/linux-daxLinus Torvalds
Pull XArray fixes from Matthew Wilcox: "These all fix various bugs, some of which people have tripped over and some of which have been caught by automatic tools" * tag 'xarray-5.4' of git://git.infradead.org/users/willy/linux-dax: idr: Fix idr_alloc_u32 on 32-bit systems idr: Fix integer overflow in idr_for_each_entry radix tree: Remove radix_tree_iter_find idr: Fix idr_get_next_ul race with idr_remove XArray: Fix xas_next() with a single entry at 0
2019-11-03idr: Fix integer overflow in idr_for_each_entryMatthew Wilcox (Oracle)
If there is an entry at INT_MAX then idr_for_each_entry() will increment id after handling it. This is undefined behaviour, and is caught by UBSAN. Adding 1U to id forces the operation to be carried out as an unsigned addition which (when assigned to id) will result in INT_MIN. Since there is never an entry stored at INT_MIN, idr_get_next() will return NULL, ending the loop as expected. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2019-07-01idr: introduce idr_for_each_entry_continue_ul()Cong Wang
Similarly, other callers of idr_get_next_ul() suffer the same overflow bug as they don't handle it properly either. Introduce idr_for_each_entry_continue_ul() to help these callers iterate from a given ID. cls_flower needs more care here because it still has overflow when does arg->cookie++, we have to fold its nested loops into one and remove the arg->cookie++. Fixes: 01683a146999 ("net: sched: refactor flower walk to iterate over idr") Fixes: 12d6066c3b29 ("net/mlx5: Add flow counters idr") Reported-by: Li Shuang <shuali@redhat.com> Cc: Davide Caratti <dcaratti@redhat.com> Cc: Vlad Buslov <vladbu@mellanox.com> Cc: Chris Mi <chrism@mellanox.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Tested-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-01idr: fix overflow case for idr_for_each_entry_ul()Cong Wang
idr_for_each_entry_ul() is buggy as it can't handle overflow case correctly. When we have an ID == UINT_MAX, it becomes an infinite loop. This happens when running on 32-bit CPU where unsigned long has the same size with unsigned int. There is no better way to fix this than casting it to a larger integer, but we can't just 64 bit integer on 32 bit CPU. Instead we could just use an additional integer to help us to detect this overflow case, that is, adding a new parameter to this macro. Fortunately tc action is its only user right now. Fixes: 65a206c01e8e ("net/sched: Change act_api and act_xxx modules to use IDR") Reported-by: Li Shuang <shuali@redhat.com> Tested-by: Davide Caratti <dcaratti@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Chris Mi <chrism@mellanox.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 220Thomas Gleixner
Based on 1 normalized pattern(s): distributed under the gnu gpl license version 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 1 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Steve Winslow <swinslow@gmail.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190528171439.854676954@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-21ida: Convert to XArrayMatthew Wilcox
Use the XA_TRACK_FREE ability to track which entries have a free bit, similarly to how it uses the radix tree's IDR_FREE tag. This eliminates the per-cpu ida_bitmap preload, and fixes the memory consumption regression I introduced when making the IDR able to store any pointer. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-08-26Merge branch 'ida-4.19' of git://git.infradead.org/users/willy/linux-daxLinus Torvalds
Pull IDA updates from Matthew Wilcox: "A better IDA API: id = ida_alloc(ida, GFP_xxx); ida_free(ida, id); rather than the cumbersome ida_simple_get(), ida_simple_remove(). The new IDA API is similar to ida_simple_get() but better named. The internal restructuring of the IDA code removes the bitmap preallocation nonsense. I hope the net -200 lines of code is convincing" * 'ida-4.19' of git://git.infradead.org/users/willy/linux-dax: (29 commits) ida: Change ida_get_new_above to return the id ida: Remove old API test_ida: check_ida_destroy and check_ida_alloc test_ida: Convert check_ida_conv to new API test_ida: Move ida_check_max test_ida: Move ida_check_leaf idr-test: Convert ida_check_nomem to new API ida: Start new test_ida module target/iscsi: Allocate session IDs from an IDA iscsi target: fix session creation failure handling drm/vmwgfx: Convert to new IDA API dmaengine: Convert to new IDA API ppc: Convert vas ID allocation to new IDA API media: Convert entity ID allocation to new IDA API ppc: Convert mmu context allocation to new IDA API Convert net_namespace to new IDA API cb710: Convert to new IDA API rsxx: Convert to new IDA API osd: Convert to new IDA API sd: Convert to new IDA API ...
2018-08-21ida: Remove old APIMatthew Wilcox
Delete ida_pre_get(), ida_get_new(), ida_get_new_above() and ida_remove() from the public API. Some of these functions still exist as internal helpers, but they should not be called by consumers. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-08-21ida: Add new APIMatthew Wilcox
Add ida_alloc(), ida_alloc_min(), ida_alloc_max(), ida_alloc_range() and ida_free(). The ida_alloc_max() and ida_alloc_range() functions differ from ida_simple_get() in that they take an inclusive 'max' parameter instead of an exclusive 'end' parameter. Callers are about evenly split whether they'd like inclusive or exclusive parameters and 'max' is easier to document than 'end'. Change the IDA allocation to first attempt to allocate a bit using existing memory, and only allocate memory afterwards. Also change the behaviour of 'min' > INT_MAX from being a BUG() to returning -ENOSPC. Leave compatibility wrappers in place for ida_simple_get() and ida_simple_remove() to avoid changing all callers. Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-06-18IDR: Expose the XArray lockwilly@infradead.org
Allow users of the IDR to use the XArray lock for their own synchronisation purposes. The IDR continues to rely on the caller to handle locking, but this lets the caller use the lock embedded in the IDR data structure instead of allocating their own lock. Signed-off-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-04-11xarray: add the xa_lock to the radix_tree_rootMatthew Wilcox
This results in no change in structure size on 64-bit machines as it fits in the padding between the gfp_t and the void *. 32-bit machines will grow the structure from 8 to 12 bytes. Almost all radix trees are protected with (at least) a spinlock, so as they are converted from radix trees to xarrays, the data structures will shrink again. Initialising the spinlock requires a name for the benefit of lockdep, so RADIX_TREE_INIT() now needs to know the name of the radix tree it's initialising, and so do IDR_INIT() and IDA_INIT(). Also add the xa_lock() and xa_unlock() family of wrappers to make it easier to use the lock. If we could rely on -fplan9-extensions in the compiler, we could avoid all of this syntactic sugar, but that wasn't added until gcc 4.6. Link: http://lkml.kernel.org/r/20180313132639.17387-8-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11radix tree: use GFP_ZONEMASK bits of gfp_t for flagsMatthew Wilcox
Patch series "XArray", v9. (First part thereof). This patchset is, I believe, appropriate for merging for 4.17. It contains the XArray implementation, to eventually replace the radix tree, and converts the page cache to use it. This conversion keeps the radix tree and XArray data structures in sync at all times. That allows us to convert the page cache one function at a time and should allow for easier bisection. Other than renaming some elements of the structures, the data structures are fundamentally unchanged; a radix tree walk and an XArray walk will touch the same number of cachelines. I have changes planned to the XArray data structure, but those will happen in future patches. Improvements the XArray has over the radix tree: - The radix tree provides operations like other trees do; 'insert' and 'delete'. But what most users really want is an automatically resizing array, and so it makes more sense to give users an API that is like an array -- 'load' and 'store'. We still have an 'insert' operation for users that really want that semantic. - The XArray considers locking as part of its API. This simplifies a lot of users who formerly had to manage their own locking just for the radix tree. It also improves code generation as we can now tell RCU that we're holding a lock and it doesn't need to generate as much fencing code. The other advantage is that tree nodes can be moved (not yet implemented). - GFP flags are now parameters to calls which may need to allocate memory. The radix tree forced users to decide what the allocation flags would be at creation time. It's much clearer to specify them at allocation time. - Memory is not preloaded; we don't tie up dozens of pages on the off chance that the slab allocator fails. Instead, we drop the lock, allocate a new node and retry the operation. We have to convert all the radix tree, IDA and IDR preload users before we can realise this benefit, but I have not yet found a user which cannot be converted. - The XArray provides a cmpxchg operation. The radix tree forces users to roll their own (and at least four have). - Iterators take a 'max' parameter. That simplifies many users and will reduce the amount of iteration done. - Iteration can proceed backwards. We only have one user for this, but since it's called as part of the pagefault readahead algorithm, that seemed worth mentioning. - RCU-protected pointers are not exposed as part of the API. There are some fun bugs where the page cache forgets to use rcu_dereference() in the current codebase. - Value entries gain an extra bit compared to radix tree exceptional entries. That gives us the extra bit we need to put huge page swap entries in the page cache. - Some iterators now take a 'filter' argument instead of having separate iterators for tagged/untagged iterations. The page cache is improved by this: - Shorter, easier to read code - More efficient iterations - Reduction in size of struct address_space - Fewer walks from the top of the data structure; the XArray API encourages staying at the leaf node and conducting operations there. This patch (of 8): None of these bits may be used for slab allocations, so we can use them as radix tree flags as long as we mask them off before passing them to the slab allocator. Move the IDR flag from the high bits to the GFP_ZONEMASK bits. Link: http://lkml.kernel.org/r/20180313132639.17387-3-willy@infradead.org Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Acked-by: Jeff Layton <jlayton@kernel.org> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06idr: Add documentationMatthew Wilcox
Move the idr kernel-doc to its own idr.rst file and add a few paragraphs about how to use it. Also add some more kernel-doc. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2018-02-06idr: Make 1-based IDRs more efficientMatthew Wilcox
About 20% of the IDR users in the kernel want the allocated IDs to start at 1. The implementation currently searches all the way down the left hand side of the tree, finds no free ID other than ID 0, walks all the way back up, and then all the way down again. This patch 'rebases' the ID so we fill the entire radix tree, rather than leave a gap at 0. Chris Wilson says: "I did the quick hack of allocating index 0 of the idr and that eradicated idr_get_free() from being at the top of the profiles for the many-object stress tests. This improvement will be much appreciated." Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2018-02-06idr: Rename idr_for_each_entry_extMatthew Wilcox
Most places in the kernel that we need to distinguish functions by the type of their arguments, we use '_ul' as a suffix for the unsigned long variant, not '_ext'. Also add kernel-doc. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2018-02-06idr: Remove idr_alloc_extMatthew Wilcox
It has no more users, so remove it. Move idr_alloc() back into idr.c, move the guts of idr_alloc_cmn() into idr_alloc_u32(), remove the wrappers around idr_get_free_cmn() and rename it to idr_get_free(). While there is now no interface to allocate IDs larger than a u32, the IDR internals remain ready to handle a larger ID should a need arise. These changes make it possible to provide the guarantee that, if the nextid pointer points into the object, the object's ID will be initialised before a concurrent lookup can find the object. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2018-02-06idr: Add idr_alloc_u32 helperMatthew Wilcox
All current users of idr_alloc_ext() actually want to allocate a u32 and idr_alloc_u32() fits their needs better. Like idr_get_next(), it uses a 'nextid' argument which serves as both a pointer to the start ID and the assigned ID (instead of a separate minimum and pointer-to-assigned-ID argument). It uses a 'max' argument rather than 'end' because the semantics that idr_alloc has for 'end' don't work well for unsigned types. Since idr_alloc_u32() returns an errno instead of the allocated ID, mark it as __must_check to help callers use it correctly. Include copious kernel-doc. Chris Mi <chrism@mellanox.com> has promised to contribute test-cases for idr_alloc_u32. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2018-02-06idr: Delete idr_find_ext functionMatthew Wilcox
Simply changing idr_remove's 'id' argument to 'unsigned long' works for all callers. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2018-02-06idr: Delete idr_replace_ext functionMatthew Wilcox
Changing idr_replace's 'id' argument to 'unsigned long' works for all callers. Callers which passed a negative ID now get -ENOENT instead of -EINVAL. No callers relied on this error value. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2018-02-06idr: Delete idr_remove_ext functionMatthew Wilcox
Simply changing idr_remove's 'id' argument to 'unsigned long' suffices for all callers. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2017-12-14include/linux/idr.h: add #include <linux/bug.h>Wei Wang
The <linux/bug.h> was removed from radix-tree.h by commit f5bba9d11a25 ("include/linux/radix-tree.h: remove unneeded #include <linux/bug.h>"). Since that commit, tools/testing/radix-tree/ couldn't pass compilation due to tools/testing/radix-tree/idr.c:17: undefined reference to WARN_ON_ONCE. This patch adds the bug.h header to idr.h to solve the issue. Link: http://lkml.kernel.org/r/1511963726-34070-2-git-send-email-wei.w.wang@intel.com Fixes: f5bba9d11a2 ("include/linux/radix-tree.h: remove unneeded #include <linux/bug.h>") Signed-off-by: Wei Wang <wei.w.wang@intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Eric Biggers <ebiggers@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-08-30idr: Add new APIs to support unsigned longChris Mi
The following new APIs are added: int idr_alloc_ext(struct idr *idr, void *ptr, unsigned long *index, unsigned long start, unsigned long end, gfp_t gfp); void *idr_remove_ext(struct idr *idr, unsigned long id); void *idr_find_ext(const struct idr *idr, unsigned long id); void *idr_replace_ext(struct idr *idr, void *ptr, unsigned long id); void *idr_get_next_ext(struct idr *idr, unsigned long *nextid); Signed-off-by: Chris Mi <chrism@mellanox.com> Signed-off-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-13idr: Return the deleted entry from idr_removeMatthew Wilcox
It is a relatively common idiom (8 instances) to first look up an IDR entry, and then remove it from the tree if it is found, possibly doing further operations upon the entry afterwards. If we change idr_remove() to return the removed object, all of these users can save themselves a walk of the IDR tree. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2017-02-13ida: Move ida_bitmap to a percpu variableMatthew Wilcox
When we preload the IDA, we allocate an IDA bitmap. Instead of storing that preallocated bitmap in the IDA, we store it in a percpu variable. Generally there are more IDAs in the system than CPUs, so this cuts down on the number of preallocated bitmaps that are unused, and about half of the IDA users did not call ida_destroy() so they were leaking IDA bitmaps. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
2017-02-13Reimplement IDR and IDA using the radix treeMatthew Wilcox
The IDR is very similar to the radix tree. It has some functionality that the radix tree did not have (alloc next free, cyclic allocation, a callback-based for_each, destroy tree), which is readily implementable on top of the radix tree. A few small changes were needed in order to use a tag to represent nodes with free space below them. More extensive changes were needed to support storing NULL as a valid entry in an IDR. Plain radix trees still interpret NULL as a not-present entry. The IDA is reimplemented as a client of the newly enhanced radix tree. As in the current implementation, it uses a bitmap at the last level of the tree. Signed-off-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2016-12-14idr: reduce the number of bits per level from 8 to 6Matthew Wilcox
In preparation for merging the IDR and radix tree, reduce the fanout at each level from 256 to 64. If this causes a performance problem then a bisect will point to this commit, and we'll have a better idea about what we might do to fix it. Link: http://lkml.kernel.org/r/1480369871-5271-66-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-14rxrpc: abstract away knowledge of IDR internalsMatthew Wilcox
Add idr_get_cursor() / idr_set_cursor() APIs, and remove the reference to IDR_SIZE. Link: http://lkml.kernel.org/r/1480369871-5271-65-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: David Howells <dhowells@redhat.com> Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-14idr: add ida_is_emptyMatthew Wilcox
Two of the USB Gadgets were poking around in the internals of struct ida in order to determine if it is empty. Add the appropriate abstraction. Link: http://lkml.kernel.org/r/1480369871-5271-63-git-send-email-mawilcox@linuxonhyperv.com Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Acked-by: Konstantin Khlebnikov <koct9i@gmail.com> Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Felipe Balbi <balbi@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-25drbd: Backport the "status" commandAndreas Gruenbacher
The status command originates the drbd9 code base. While for now we keep the status information in /proc/drbd available, this commit allows the user base to gracefully migrate their monitoring infrastructure to the new status reporting interface. In drbd9 no status information is exposed through /proc/drbd. Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2014-06-06idr: reorder the fieldsLai Jiangshan
idr_layer->layer is always accessed in read path, move it in the front. idr_layer->bitmap is moved on the bottom. And rcu_head shares with bitmap due to they do not be accessed at the same time. idr->id_free/id_free_cnt/lock are free list fields, and moved to the bottom. They will be removed in near future. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07idr: remove dead codeStephen Hemminger
Remove no longer used deprecated code, and make local functions static. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Acked-by: Jean Delvare <jdelvare@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Cc: Jeff Layton <jlayton@redhat.com> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: George Spelvin <linux@horizon.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-02Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina: "Usual rocket science -- mostly documentation and comment updates" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: sparse: fix comment doc: fix double words isdn: capi: fix "CAPI_VERSION" comment doc: DocBook: Fix typos in xml and template file Bluetooth: add module name for btwilink driver core: unexport static function create_syslog_header mmc: core: typo fix in printk specifier ARM: spear: clean up editing mistake net-sysfs: fix comment typo 'CONFIG_SYFS' doc: Insert MODULE_ in module-signing macros Documentation: update URL to hfsplus Technote 1150 gpio: update path to documentation ixgbe: Fix format string in ixgbe_fcoe. Kconfig: Remove useless "default N" lines user_namespace.c: Remove duplicated word in comment CREDITS: fix formatting treewide: Fix typo in Documentation/DocBook mm: Fix warning on make htmldocs caused by slab.c ata: ata-samsung_cf: cleanup in header file idr: remove unused prototype of idr_free()
2014-02-17idr: Add new function idr_is_empty()Andreas Gruenbacher
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com> Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
2014-01-30idr: remove unused prototype of idr_free()Vladimir Davydov
There is no such function. Remove the redundant prototype. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-05-08Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block driver updates from Jens Axboe: "It might look big in volume, but when categorized, not a lot of drivers are touched. The pull request contains: - mtip32xx fixes from Micron. - A slew of drbd updates, this time in a nicer series. - bcache, a flash/ssd caching framework from Kent. - Fixes for cciss" * 'for-3.10/drivers' of git://git.kernel.dk/linux-block: (66 commits) bcache: Use bd_link_disk_holder() bcache: Allocator cleanup/fixes cciss: bug fix to prevent cciss from loading in kdump crash kernel cciss: add cciss_allow_hpsa module parameter drivers/block/mg_disk.c: add CONFIG_PM_SLEEP to suspend/resume functions mtip32xx: Workaround for unaligned writes bcache: Make sure blocksize isn't smaller than device blocksize bcache: Fix merge_bvec_fn usage for when it modifies the bvm bcache: Correctly check against BIO_MAX_PAGES bcache: Hack around stuff that clones up to bi_max_vecs bcache: Set ra_pages based on backing device's ra_pages bcache: Take data offset from the bdev superblock. mtip32xx: mtip32xx: Disable TRIM support mtip32xx: fix a smatch warning bcache: Disable broken btree fuzz tester bcache: Fix a format string overflow bcache: Fix a minor memory leak on device teardown bcache: Documentation updates bcache: Use WARN_ONCE() instead of __WARN() bcache: Add missing #include <linux/prefetch.h> ...
2013-04-29idr: introduce idr_alloc_cyclic()Jeff Layton
As Tejun points out, there are several users of the IDR facility that attempt to use it in a cyclic fashion. These users are likely to see -ENOSPC errors after the counter wraps one or more times however. This patchset adds a new idr_alloc_cyclic routine and converts several of these users to it. Many of these users are in obscure parts of the kernel, and I don't have a good way to test some of them. The change is pretty straightforward though, so hopefully it won't be an issue. There is one other cyclic user of idr_alloc that I didn't touch in ipc/util.c. That one is doing some strange stuff that I didn't quite understand, but it looks like it should probably be converted later somehow. This patch: Thus spake Tejun Heo: Ooh, BTW, the cyclic allocation is broken. It's prone to -ENOSPC after the first wraparound. There are several cyclic users in the kernel and I think it probably would be best to implement cyclic support in idr. This patch does that by adding new idr_alloc_cyclic function that such users in the kernel can use. With this, there's no need for a caller to keep track of the last value used as that's now tracked internally. This should prevent the ENOSPC problems that can hit when the "last allocated" counter exceeds INT_MAX. Later patches will convert existing cyclic users to the new interface. Signed-off-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Tejun Heo <tj@kernel.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Eric Paris <eparis@parisplace.org> Cc: Jack Morgenstein <jackm@dev.mellanox.co.il> Cc: John McCutchan <john@johnmccutchan.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Or Gerlitz <ogerlitz@mellanox.com> Cc: Robert Love <rlove@rlove.org> Cc: Roland Dreier <roland@purestorage.com> Cc: Sridhar Samudrala <sri@us.ibm.com> Cc: Steve Wise <swise@opengridcomputing.com> Cc: Tom Tucker <tom@opengridcomputing.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-28idr: document exit conditions on idr_for_each_entry betterGeorge Spelvin
And some manual common subexpression elimination which may help the compiler produce smaller code. Signed-off-by: George Spelvin <linux@horizon.com> Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-03-13idr: deprecate idr_pre_get() and idr_get_new[_above]()Tejun Heo
Now that all in-kernel users are converted to ues the new alloc interface, mark the old interface deprecated. We should be able to remove these in a few releases. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-12idr: fix new kernel-doc warningsRandy Dunlap
Fix new kernel-doc warnings in idr: Warning(include/linux/idr.h:113): No description found for parameter 'idr' Warning(include/linux/idr.h:113): Excess function parameter 'idp' description in 'idr_find' Warning(lib/idr.c:232): Excess function parameter 'id' description in 'sub_alloc' Warning(lib/idr.c:232): Excess function parameter 'id' description in 'sub_alloc' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27idr: implement lookup hintTejun Heo
While idr lookup isn't a particularly heavy operation, it still is too substantial to use in hot paths without worrying about the performance implications. With recent changes, each idr_layer covers 256 slots which should be enough to cover most use cases with single idr_layer making lookup hint very attractive. This patch adds idr->hint which points to the idr_layer which allocated an ID most recently and the fast path lookup becomes if (look up target's prefix matches that of the hinted layer) return hint->ary[ID's offset in the leaf layer]; which can be inlined. idr->hint is set to the leaf node on idr_fill_slot() and cleared from free_layer(). [andriy.shevchenko@linux.intel.com: always do slow path when hint is uninitialized] Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27idr: add idr_layer->prefixTejun Heo
Add a field which carries the prefix of ID the idr_layer covers. This will be used to implement lookup hint. This patch doesn't make use of the new field and doesn't introduce any behavior difference. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27idr: make idr_layer largerTejun Heo
With recent preloading changes, idr no longer keeps full layer cache per each idr instance (used to be ~6.5k per idr on 64bit) and the previous patch removed restriction on the bitmap size. Both now allow us to have larger layers. Increase IDR_BITS to 8 regardless of BITS_PER_LONG. Each layer is slightly larger than 2k on 64bit and 1k on 32bit and carries 256 entries. The size isn't too large, especially compared to what we used to waste on per-idr caches, and 256 entries should be able to serve most use cases with single layer. The max tree depth is 4 which is much better than the previous 6 on 64bit and 7 on 32bit. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27idr: remove length restriction from idr_layer->bitmapTejun Heo
Currently, idr->bitmap is declared as an unsigned long which restricts the number of bits an idr_layer can contain. All bitops can handle arbitrary positive integer bit number and there's no reason for this restriction. Declare idr_layer->bitmap using DECLARE_BITMAP() instead of a single unsigned long. * idr_layer->bitmap is now an array. '&' dropped from params to bitops. * Replaced "== IDR_FULL" tests with bitmap_full() and removed IDR_FULL. * Replaced find_next_bit() on ~bitmap with find_next_zero_bit(). * Replaced "bitmap = 0" with bitmap_clear(). This patch doesn't (or at least shouldn't) introduce any behavior changes. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27idr: remove MAX_IDR_MASK and move left MAX_IDR_* into idr.cTejun Heo
MAX_IDR_MASK is another weirdness in the idr interface. As idr covers whole positive integer range, it's defined as 0x7fffffff or INT_MAX. Its usage in idr_find(), idr_replace() and idr_remove() is bizarre. They basically mask off the sign bit and operate on the rest, so if the caller, by accident, passes in a negative number, the sign bit will be masked off and the remaining part will be used as if that was the input, which is worse than crashing. The constant is visible in idr.h and there are several users in the kernel. * drivers/i2c/i2c-core.c:i2c_add_numbered_adapter() Basically used to test if adap->nr is a negative number which isn't -1 and returns -EINVAL if so. idr_alloc() already has negative @start checking (w/ WARN_ON_ONCE), so this can go away. * drivers/infiniband/core/cm.c:cm_alloc_id() drivers/infiniband/hw/mlx4/cm.c:id_map_alloc() Used to wrap cyclic @start. Can be replaced with max(next, 0). Note that this type of cyclic allocation using idr is buggy. These are prone to spurious -ENOSPC failure after the first wraparound. * fs/super.c:get_anon_bdev() The ID allocated from ida is masked off before being tested whether it's inside valid range. ida allocated ID can never be a negative number and the masking is unnecessary. Update idr_*() functions to fail with -EINVAL when negative @id is specified and update other MAX_IDR_MASK users as described above. This leaves MAX_IDR_MASK without any user, remove it and relocate other MAX_IDR_* constants to lib/idr.c. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jean Delvare <khali@linux-fr.org> Cc: Roland Dreier <roland@kernel.org> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Hal Rosenstock <hal.rosenstock@gmail.com> Cc: "Marciniszyn, Mike" <mike.marciniszyn@intel.com> Cc: Jack Morgenstein <jackm@dev.mellanox.co.il> Cc: Or Gerlitz <ogerlitz@mellanox.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Wolfram Sang <wolfram@the-dreams.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27idr: implement idr_preload[_end]() and idr_alloc()Tejun Heo
The current idr interface is very cumbersome. * For all allocations, two function calls - idr_pre_get() and idr_get_new*() - should be made. * idr_pre_get() doesn't guarantee that the following idr_get_new*() will not fail from memory shortage. If idr_get_new*() returns -EAGAIN, the caller is expected to retry pre_get and allocation. * idr_get_new*() can't enforce upper limit. Upper limit can only be enforced by allocating and then freeing if above limit. * idr_layer buffer is unnecessarily per-idr. Each idr ends up keeping around MAX_IDR_FREE idr_layers. The memory consumed per idr is under two pages but it makes it difficult to make idr_layer larger. This patch implements the following new set of allocation functions. * idr_preload[_end]() - Similar to radix preload but doesn't fail. The first idr_alloc() inside preload section can be treated as if it were called with @gfp_mask used for idr_preload(). * idr_alloc() - Allocate an ID w/ lower and upper limits. Takes @gfp_flags and can be used w/o preloading. When used inside preloaded section, the allocation mask of preloading can be assumed. If idr_alloc() can be called from a context which allows sufficiently relaxed @gfp_mask, it can be used by itself. If, for example, idr_alloc() is called inside spinlock protected region, preloading can be used like the following. idr_preload(GFP_KERNEL); spin_lock(lock); id = idr_alloc(idr, ptr, start, end, GFP_NOWAIT); spin_unlock(lock); idr_preload_end(); if (id < 0) error; which is much simpler and less error-prone than idr_pre_get and idr_get_new*() loop. The new interface uses per-pcu idr_layer buffer and thus the number of idr's in the system doesn't affect the amount of memory used for preloading. idr_layer_alloc() is introduced to handle idr_layer allocations for both old and new ID allocation paths. This is a bit hairy now but the new interface is expected to replace the old and the internal implementation eventually will become simpler. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27idr: remove _idr_rc_to_errno() hackTejun Heo
idr uses -1, IDR_NEED_TO_GROW and IDR_NOMORE_SPACE to communicate exception conditions internally. The return value is later translated to errno values using _idr_rc_to_errno(). This is confusing. Drop the custom ones and consistently use -EAGAIN for "tree needs to grow", -ENOMEM for "need more memory" and -ENOSPC for "ran out of ID space". Due to the weird memory preloading mechanism, [ra]_get_new*() return -EAGAIN on memory shortage, so we need to substitute -ENOMEM w/ -EAGAIN on those interface functions. They'll eventually be cleaned up and the translations will go away. This patch doesn't introduce any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27idr: relocate idr_for_each_entry() and reorganize id[r|a]_get_new()Tejun Heo
* Move idr_for_each_entry() definition next to other idr related definitions. * Make id[r|a]_get_new() inline wrappers of id[r|a]_get_new_above(). This changes the implementation of idr_get_new() but the new implementation is trivial. This patch doesn't introduce any functional change. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27idr: cosmetic updates to struct / initializer definitionsTejun Heo
* Tab align fields like a normal person. * Drop the unnecessary 0 inits from IDR_INIT(). This patch is purely cosmetic. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27idr: deprecate idr_remove_all()Tejun Heo
There was only one legitimate use of idr_remove_all() and a lot more of incorrect uses (or lack of it). Now that idr_destroy() implies idr_remove_all() and all the in-kernel users updated not to use it, there's no reason to keep it around. Mark it deprecated so that we can later unexport it. idr_remove_all() is made an inline function calling __idr_remove_all() to avoid triggering deprecated warning on EXPORT_SYMBOL(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>