Merge branch 'idr-2018-02-06' of git://git.infradead.org/users/willy/linux-dax
Pull idr updates from Matthew Wilcox: - test-suite improvements - replace the extended API by improving the normal API - performance improvement for IDRs which are 1-based rather than 0-based - add documentation * 'idr-2018-02-06' of git://git.infradead.org/users/willy/linux-dax: idr: Add documentation idr: Make 1-based IDRs more efficient idr: Warn if old iterators see large IDs idr: Rename idr_for_each_entry_ext idr: Remove idr_alloc_ext cls_u32: Convert to idr_alloc_u32 cls_u32: Reinstate cyclic allocation cls_flower: Convert to idr_alloc_u32 cls_bpf: Convert to use idr_alloc_u32 cls_basic: Convert to use idr_alloc_u32 cls_api: Convert to idr_alloc_u32 net sched actions: Convert to use idr_alloc_u32 idr: Add idr_alloc_u32 helper idr: Delete idr_find_ext function idr: Delete idr_replace_ext function idr: Delete idr_remove_ext function IDR test suite: Check handling negative end correctly idr test suite: Fix ida_test_random() radix tree test suite: Remove ARRAY_SIZE
This commit is contained in:
Linus Torvalds
253
lib/idr.c
253
lib/idr.c
@@ -1,4 +1,5 @@
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#include <linux/bitmap.h>
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#include <linux/bug.h>
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#include <linux/export.h>
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#include <linux/idr.h>
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#include <linux/slab.h>
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@@ -7,71 +8,184 @@
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DEFINE_PER_CPU(struct ida_bitmap *, ida_bitmap);
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static DEFINE_SPINLOCK(simple_ida_lock);
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int idr_alloc_cmn(struct idr *idr, void *ptr, unsigned long *index,
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unsigned long start, unsigned long end, gfp_t gfp,
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bool ext)
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/**
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* idr_alloc_u32() - Allocate an ID.
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* @idr: IDR handle.
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* @ptr: Pointer to be associated with the new ID.
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* @nextid: Pointer to an ID.
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* @max: The maximum ID to allocate (inclusive).
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* @gfp: Memory allocation flags.
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*
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* Allocates an unused ID in the range specified by @nextid and @max.
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* Note that @max is inclusive whereas the @end parameter to idr_alloc()
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* is exclusive. The new ID is assigned to @nextid before the pointer
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* is inserted into the IDR, so if @nextid points into the object pointed
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* to by @ptr, a concurrent lookup will not find an uninitialised ID.
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*
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* The caller should provide their own locking to ensure that two
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* concurrent modifications to the IDR are not possible. Read-only
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* accesses to the IDR may be done under the RCU read lock or may
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* exclude simultaneous writers.
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*
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* Return: 0 if an ID was allocated, -ENOMEM if memory allocation failed,
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* or -ENOSPC if no free IDs could be found. If an error occurred,
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* @nextid is unchanged.
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*/
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int idr_alloc_u32(struct idr *idr, void *ptr, u32 *nextid,
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unsigned long max, gfp_t gfp)
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{
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struct radix_tree_iter iter;
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void __rcu **slot;
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int base = idr->idr_base;
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int id = *nextid;
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if (WARN_ON_ONCE(radix_tree_is_internal_node(ptr)))
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return -EINVAL;
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if (WARN_ON_ONCE(!(idr->idr_rt.gfp_mask & ROOT_IS_IDR)))
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idr->idr_rt.gfp_mask |= IDR_RT_MARKER;
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radix_tree_iter_init(&iter, start);
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if (ext)
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slot = idr_get_free_ext(&idr->idr_rt, &iter, gfp, end);
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else
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slot = idr_get_free(&idr->idr_rt, &iter, gfp, end);
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id = (id < base) ? 0 : id - base;
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radix_tree_iter_init(&iter, id);
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slot = idr_get_free(&idr->idr_rt, &iter, gfp, max - base);
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if (IS_ERR(slot))
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return PTR_ERR(slot);
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*nextid = iter.index + base;
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/* there is a memory barrier inside radix_tree_iter_replace() */
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radix_tree_iter_replace(&idr->idr_rt, &iter, slot, ptr);
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radix_tree_iter_tag_clear(&idr->idr_rt, &iter, IDR_FREE);
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if (index)
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*index = iter.index;
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return 0;
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}
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EXPORT_SYMBOL_GPL(idr_alloc_cmn);
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EXPORT_SYMBOL_GPL(idr_alloc_u32);
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/**
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* idr_alloc_cyclic - allocate new idr entry in a cyclical fashion
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* @idr: idr handle
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* @ptr: pointer to be associated with the new id
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* @start: the minimum id (inclusive)
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* @end: the maximum id (exclusive)
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* @gfp: memory allocation flags
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* idr_alloc() - Allocate an ID.
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* @idr: IDR handle.
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* @ptr: Pointer to be associated with the new ID.
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* @start: The minimum ID (inclusive).
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* @end: The maximum ID (exclusive).
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* @gfp: Memory allocation flags.
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*
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* Allocates an ID larger than the last ID allocated if one is available.
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* If not, it will attempt to allocate the smallest ID that is larger or
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* equal to @start.
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* Allocates an unused ID in the range specified by @start and @end. If
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* @end is <= 0, it is treated as one larger than %INT_MAX. This allows
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* callers to use @start + N as @end as long as N is within integer range.
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*
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* The caller should provide their own locking to ensure that two
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* concurrent modifications to the IDR are not possible. Read-only
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* accesses to the IDR may be done under the RCU read lock or may
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* exclude simultaneous writers.
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*
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* Return: The newly allocated ID, -ENOMEM if memory allocation failed,
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* or -ENOSPC if no free IDs could be found.
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*/
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int idr_alloc(struct idr *idr, void *ptr, int start, int end, gfp_t gfp)
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{
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u32 id = start;
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int ret;
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if (WARN_ON_ONCE(start < 0))
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return -EINVAL;
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ret = idr_alloc_u32(idr, ptr, &id, end > 0 ? end - 1 : INT_MAX, gfp);
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if (ret)
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return ret;
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return id;
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}
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EXPORT_SYMBOL_GPL(idr_alloc);
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/**
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* idr_alloc_cyclic() - Allocate an ID cyclically.
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* @idr: IDR handle.
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* @ptr: Pointer to be associated with the new ID.
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* @start: The minimum ID (inclusive).
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* @end: The maximum ID (exclusive).
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* @gfp: Memory allocation flags.
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*
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* Allocates an unused ID in the range specified by @nextid and @end. If
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* @end is <= 0, it is treated as one larger than %INT_MAX. This allows
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* callers to use @start + N as @end as long as N is within integer range.
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* The search for an unused ID will start at the last ID allocated and will
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* wrap around to @start if no free IDs are found before reaching @end.
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*
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* The caller should provide their own locking to ensure that two
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* concurrent modifications to the IDR are not possible. Read-only
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* accesses to the IDR may be done under the RCU read lock or may
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* exclude simultaneous writers.
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*
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* Return: The newly allocated ID, -ENOMEM if memory allocation failed,
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* or -ENOSPC if no free IDs could be found.
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*/
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int idr_alloc_cyclic(struct idr *idr, void *ptr, int start, int end, gfp_t gfp)
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{
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int id, curr = idr->idr_next;
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u32 id = idr->idr_next;
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int err, max = end > 0 ? end - 1 : INT_MAX;
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if (curr < start)
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curr = start;
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if ((int)id < start)
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id = start;
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id = idr_alloc(idr, ptr, curr, end, gfp);
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if ((id == -ENOSPC) && (curr > start))
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id = idr_alloc(idr, ptr, start, curr, gfp);
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if (id >= 0)
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idr->idr_next = id + 1U;
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err = idr_alloc_u32(idr, ptr, &id, max, gfp);
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if ((err == -ENOSPC) && (id > start)) {
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id = start;
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err = idr_alloc_u32(idr, ptr, &id, max, gfp);
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}
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if (err)
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return err;
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idr->idr_next = id + 1;
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return id;
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}
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EXPORT_SYMBOL(idr_alloc_cyclic);
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/**
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* idr_for_each - iterate through all stored pointers
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* @idr: idr handle
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* @fn: function to be called for each pointer
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* @data: data passed to callback function
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* idr_remove() - Remove an ID from the IDR.
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* @idr: IDR handle.
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* @id: Pointer ID.
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*
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* Removes this ID from the IDR. If the ID was not previously in the IDR,
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* this function returns %NULL.
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*
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* Since this function modifies the IDR, the caller should provide their
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* own locking to ensure that concurrent modification of the same IDR is
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* not possible.
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*
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* Return: The pointer formerly associated with this ID.
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*/
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void *idr_remove(struct idr *idr, unsigned long id)
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{
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return radix_tree_delete_item(&idr->idr_rt, id - idr->idr_base, NULL);
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}
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EXPORT_SYMBOL_GPL(idr_remove);
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/**
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* idr_find() - Return pointer for given ID.
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* @idr: IDR handle.
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* @id: Pointer ID.
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*
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* Looks up the pointer associated with this ID. A %NULL pointer may
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* indicate that @id is not allocated or that the %NULL pointer was
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* associated with this ID.
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*
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* This function can be called under rcu_read_lock(), given that the leaf
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* pointers lifetimes are correctly managed.
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*
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* Return: The pointer associated with this ID.
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*/
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void *idr_find(const struct idr *idr, unsigned long id)
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{
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return radix_tree_lookup(&idr->idr_rt, id - idr->idr_base);
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}
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EXPORT_SYMBOL_GPL(idr_find);
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/**
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* idr_for_each() - Iterate through all stored pointers.
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* @idr: IDR handle.
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* @fn: Function to be called for each pointer.
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* @data: Data passed to callback function.
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*
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* The callback function will be called for each entry in @idr, passing
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* the id, the pointer and the data pointer passed to this function.
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* the ID, the entry and @data.
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*
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* If @fn returns anything other than %0, the iteration stops and that
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* value is returned from this function.
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@@ -86,9 +200,14 @@ int idr_for_each(const struct idr *idr,
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{
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struct radix_tree_iter iter;
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void __rcu **slot;
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int base = idr->idr_base;
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radix_tree_for_each_slot(slot, &idr->idr_rt, &iter, 0) {
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int ret = fn(iter.index, rcu_dereference_raw(*slot), data);
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int ret;
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if (WARN_ON_ONCE(iter.index > INT_MAX))
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break;
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ret = fn(iter.index + base, rcu_dereference_raw(*slot), data);
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if (ret)
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return ret;
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}
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@@ -98,9 +217,9 @@ int idr_for_each(const struct idr *idr,
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EXPORT_SYMBOL(idr_for_each);
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/**
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* idr_get_next - Find next populated entry
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* @idr: idr handle
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* @nextid: Pointer to lowest possible ID to return
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* idr_get_next() - Find next populated entry.
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* @idr: IDR handle.
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* @nextid: Pointer to an ID.
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*
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* Returns the next populated entry in the tree with an ID greater than
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* or equal to the value pointed to by @nextid. On exit, @nextid is updated
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@@ -111,35 +230,55 @@ void *idr_get_next(struct idr *idr, int *nextid)
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{
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struct radix_tree_iter iter;
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void __rcu **slot;
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int base = idr->idr_base;
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int id = *nextid;
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slot = radix_tree_iter_find(&idr->idr_rt, &iter, *nextid);
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id = (id < base) ? 0 : id - base;
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slot = radix_tree_iter_find(&idr->idr_rt, &iter, id);
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if (!slot)
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return NULL;
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id = iter.index + base;
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*nextid = iter.index;
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if (WARN_ON_ONCE(id > INT_MAX))
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return NULL;
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*nextid = id;
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return rcu_dereference_raw(*slot);
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}
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EXPORT_SYMBOL(idr_get_next);
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void *idr_get_next_ext(struct idr *idr, unsigned long *nextid)
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/**
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* idr_get_next_ul() - Find next populated entry.
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* @idr: IDR handle.
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* @nextid: Pointer to an ID.
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*
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* Returns the next populated entry in the tree with an ID greater than
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* or equal to the value pointed to by @nextid. On exit, @nextid is updated
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* to the ID of the found value. To use in a loop, the value pointed to by
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* nextid must be incremented by the user.
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*/
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void *idr_get_next_ul(struct idr *idr, unsigned long *nextid)
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{
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struct radix_tree_iter iter;
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void __rcu **slot;
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unsigned long base = idr->idr_base;
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unsigned long id = *nextid;
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slot = radix_tree_iter_find(&idr->idr_rt, &iter, *nextid);
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id = (id < base) ? 0 : id - base;
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slot = radix_tree_iter_find(&idr->idr_rt, &iter, id);
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if (!slot)
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return NULL;
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*nextid = iter.index;
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*nextid = iter.index + base;
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return rcu_dereference_raw(*slot);
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}
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EXPORT_SYMBOL(idr_get_next_ext);
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EXPORT_SYMBOL(idr_get_next_ul);
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/**
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* idr_replace - replace pointer for given id
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* @idr: idr handle
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* @ptr: New pointer to associate with the ID
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* @id: Lookup key
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* idr_replace() - replace pointer for given ID.
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* @idr: IDR handle.
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* @ptr: New pointer to associate with the ID.
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* @id: ID to change.
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*
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* Replace the pointer registered with an ID and return the old value.
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* This function can be called under the RCU read lock concurrently with
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@@ -147,18 +286,9 @@ EXPORT_SYMBOL(idr_get_next_ext);
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* the one being replaced!).
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*
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* Returns: the old value on success. %-ENOENT indicates that @id was not
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* found. %-EINVAL indicates that @id or @ptr were not valid.
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* found. %-EINVAL indicates that @ptr was not valid.
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*/
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void *idr_replace(struct idr *idr, void *ptr, int id)
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{
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if (id < 0)
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return ERR_PTR(-EINVAL);
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return idr_replace_ext(idr, ptr, id);
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}
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EXPORT_SYMBOL(idr_replace);
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void *idr_replace_ext(struct idr *idr, void *ptr, unsigned long id)
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void *idr_replace(struct idr *idr, void *ptr, unsigned long id)
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{
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struct radix_tree_node *node;
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void __rcu **slot = NULL;
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@@ -166,6 +296,7 @@ void *idr_replace_ext(struct idr *idr, void *ptr, unsigned long id)
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if (WARN_ON_ONCE(radix_tree_is_internal_node(ptr)))
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return ERR_PTR(-EINVAL);
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id -= idr->idr_base;
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entry = __radix_tree_lookup(&idr->idr_rt, id, &node, &slot);
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if (!slot || radix_tree_tag_get(&idr->idr_rt, id, IDR_FREE))
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@@ -175,7 +306,7 @@ void *idr_replace_ext(struct idr *idr, void *ptr, unsigned long id)
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return entry;
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}
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EXPORT_SYMBOL(idr_replace_ext);
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EXPORT_SYMBOL(idr_replace);
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/**
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* DOC: IDA description
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@@ -235,7 +366,7 @@ EXPORT_SYMBOL(idr_replace_ext);
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* bitmap, which is excessive.
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*/
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#define IDA_MAX (0x80000000U / IDA_BITMAP_BITS)
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#define IDA_MAX (0x80000000U / IDA_BITMAP_BITS - 1)
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/**
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* ida_get_new_above - allocate new ID above or equal to a start id
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@@ -24,6 +24,7 @@
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#include <linux/bitmap.h>
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#include <linux/bitops.h>
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#include <linux/bug.h>
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#include <linux/cpu.h>
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#include <linux/errno.h>
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#include <linux/export.h>
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@@ -2135,7 +2136,7 @@ int ida_pre_get(struct ida *ida, gfp_t gfp)
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}
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EXPORT_SYMBOL(ida_pre_get);
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void __rcu **idr_get_free_cmn(struct radix_tree_root *root,
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void __rcu **idr_get_free(struct radix_tree_root *root,
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struct radix_tree_iter *iter, gfp_t gfp,
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unsigned long max)
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{
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