From 5ade60dda43c8906d4554374226c2eb11cc2ffba Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Tue, 20 Mar 2018 17:07:11 -0400 Subject: ida: Add new API 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 --- include/linux/idr.h | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 56 insertions(+), 3 deletions(-) (limited to 'include/linux/idr.h') diff --git a/include/linux/idr.h b/include/linux/idr.h index e856f4e0ab35..cd339da0b1aa 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -230,15 +230,68 @@ int ida_get_new_above(struct ida *ida, int starting_id, int *p_id); void ida_remove(struct ida *ida, int id); void ida_destroy(struct ida *ida); -int ida_simple_get(struct ida *ida, unsigned int start, unsigned int end, - gfp_t gfp_mask); -void ida_simple_remove(struct ida *ida, unsigned int id); +int ida_alloc_range(struct ida *, unsigned int min, unsigned int max, gfp_t); +void ida_free(struct ida *, unsigned int id); + +/** + * ida_alloc() - Allocate an unused ID. + * @ida: IDA handle. + * @gfp: Memory allocation flags. + * + * Allocate an ID between 0 and %INT_MAX, inclusive. + * + * Context: Any context. + * Return: The allocated ID, or %-ENOMEM if memory could not be allocated, + * or %-ENOSPC if there are no free IDs. + */ +static inline int ida_alloc(struct ida *ida, gfp_t gfp) +{ + return ida_alloc_range(ida, 0, ~0, gfp); +} + +/** + * ida_alloc_min() - Allocate an unused ID. + * @ida: IDA handle. + * @min: Lowest ID to allocate. + * @gfp: Memory allocation flags. + * + * Allocate an ID between @min and %INT_MAX, inclusive. + * + * Context: Any context. + * Return: The allocated ID, or %-ENOMEM if memory could not be allocated, + * or %-ENOSPC if there are no free IDs. + */ +static inline int ida_alloc_min(struct ida *ida, unsigned int min, gfp_t gfp) +{ + return ida_alloc_range(ida, min, ~0, gfp); +} + +/** + * ida_alloc_max() - Allocate an unused ID. + * @ida: IDA handle. + * @max: Highest ID to allocate. + * @gfp: Memory allocation flags. + * + * Allocate an ID between 0 and @max, inclusive. + * + * Context: Any context. + * Return: The allocated ID, or %-ENOMEM if memory could not be allocated, + * or %-ENOSPC if there are no free IDs. + */ +static inline int ida_alloc_max(struct ida *ida, unsigned int max, gfp_t gfp) +{ + return ida_alloc_range(ida, 0, max, gfp); +} static inline void ida_init(struct ida *ida) { INIT_RADIX_TREE(&ida->ida_rt, IDR_RT_MARKER | GFP_NOWAIT); } +#define ida_simple_get(ida, start, end, gfp) \ + ida_alloc_range(ida, start, (end) - 1, gfp) +#define ida_simple_remove(ida, id) ida_free(ida, id) + /** * ida_get_new - allocate new ID * @ida: idr handle -- cgit v1.2.3-59-g8ed1b From b03f8e43c9261878bf29d8cc1c3ba458cc98287e Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Mon, 18 Jun 2018 19:02:48 -0400 Subject: ida: Remove old API 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 --- include/linux/idr.h | 21 ++++----------------- lib/idr.c | 48 +++++++----------------------------------------- lib/radix-tree.c | 9 --------- 3 files changed, 11 insertions(+), 67 deletions(-) (limited to 'include/linux/idr.h') diff --git a/include/linux/idr.h b/include/linux/idr.h index cd339da0b1aa..2e1db0e36486 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -225,13 +225,9 @@ struct ida { } #define DEFINE_IDA(name) struct ida name = IDA_INIT(name) -int ida_pre_get(struct ida *ida, gfp_t gfp_mask); -int ida_get_new_above(struct ida *ida, int starting_id, int *p_id); -void ida_remove(struct ida *ida, int id); -void ida_destroy(struct ida *ida); - int ida_alloc_range(struct ida *, unsigned int min, unsigned int max, gfp_t); void ida_free(struct ida *, unsigned int id); +void ida_destroy(struct ida *ida); /** * ida_alloc() - Allocate an unused ID. @@ -292,20 +288,11 @@ static inline void ida_init(struct ida *ida) ida_alloc_range(ida, start, (end) - 1, gfp) #define ida_simple_remove(ida, id) ida_free(ida, id) -/** - * ida_get_new - allocate new ID - * @ida: idr handle - * @p_id: pointer to the allocated handle - * - * Simple wrapper around ida_get_new_above() w/ @starting_id of zero. - */ -static inline int ida_get_new(struct ida *ida, int *p_id) -{ - return ida_get_new_above(ida, 0, p_id); -} - static inline bool ida_is_empty(const struct ida *ida) { return radix_tree_empty(&ida->ida_rt); } + +/* in lib/radix-tree.c */ +int ida_pre_get(struct ida *ida, gfp_t gfp_mask); #endif /* __IDR_H__ */ diff --git a/lib/idr.c b/lib/idr.c index 760fce92f1fb..1dc52191acb6 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -320,16 +320,9 @@ EXPORT_SYMBOL(idr_replace); * ida_alloc(), ida_alloc_min(), ida_alloc_max() or ida_alloc_range(). * To free an ID, call ida_free(). * - * If you have more complex locking requirements, use a loop around - * ida_pre_get() and ida_get_new() to allocate a new ID. Then use - * ida_remove() to free an ID. You must make sure that ida_get_new() and - * ida_remove() cannot be called at the same time as each other for the - * same IDA. - * - * You can also use ida_get_new_above() if you need an ID to be allocated - * above a particular number. ida_destroy() can be used to dispose of an - * IDA without needing to free the individual IDs in it. You can use - * ida_is_empty() to find out whether the IDA has any IDs currently allocated. + * ida_destroy() can be used to dispose of an IDA without needing to + * free the individual IDs in it. You can use ida_is_empty() to find + * out whether the IDA has any IDs currently allocated. * * IDs are currently limited to the range [0-INT_MAX]. If this is an awkward * limitation, it should be quite straightforward to raise the maximum. @@ -370,25 +363,7 @@ EXPORT_SYMBOL(idr_replace); #define IDA_MAX (0x80000000U / IDA_BITMAP_BITS - 1) -/** - * ida_get_new_above - allocate new ID above or equal to a start id - * @ida: ida handle - * @start: id to start search at - * @id: pointer to the allocated handle - * - * Allocate new ID above or equal to @start. It should be called - * with any required locks to ensure that concurrent calls to - * ida_get_new_above() / ida_get_new() / ida_remove() are not allowed. - * Consider using ida_alloc_range() if you do not have complex locking - * requirements. - * - * If memory is required, it will return %-EAGAIN, you should unlock - * and go back to the ida_pre_get() call. If the ida is full, it will - * return %-ENOSPC. On success, it will return 0. - * - * @id returns a value in the range @start ... %0x7fffffff. - */ -int ida_get_new_above(struct ida *ida, int start, int *id) +static int ida_get_new_above(struct ida *ida, int start, int *id) { struct radix_tree_root *root = &ida->ida_rt; void __rcu **slot; @@ -473,16 +448,8 @@ int ida_get_new_above(struct ida *ida, int start, int *id) return 0; } } -EXPORT_SYMBOL(ida_get_new_above); -/** - * ida_remove - Free the given ID - * @ida: ida handle - * @id: ID to free - * - * This function should not be called at the same time as ida_get_new_above(). - */ -void ida_remove(struct ida *ida, int id) +static void ida_remove(struct ida *ida, int id) { unsigned long index = id / IDA_BITMAP_BITS; unsigned offset = id % IDA_BITMAP_BITS; @@ -519,9 +486,8 @@ void ida_remove(struct ida *ida, int id) } return; err: - WARN(1, "ida_remove called for id=%d which is not allocated.\n", id); + WARN(1, "ida_free called for id=%d which is not allocated.\n", id); } -EXPORT_SYMBOL(ida_remove); /** * ida_destroy() - Free all IDs. @@ -568,7 +534,7 @@ EXPORT_SYMBOL(ida_destroy); int ida_alloc_range(struct ida *ida, unsigned int min, unsigned int max, gfp_t gfp) { - int ret, id; + int ret, id = 0; unsigned long flags; if ((int)min < 0) diff --git a/lib/radix-tree.c b/lib/radix-tree.c index cc6096b97afb..bc03ecc4dfd2 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -2106,14 +2106,6 @@ void idr_preload(gfp_t gfp_mask) } EXPORT_SYMBOL(idr_preload); -/** - * ida_pre_get - reserve resources for ida allocation - * @ida: ida handle - * @gfp: memory allocation flags - * - * This function should be called before calling ida_get_new_above(). If it - * is unable to allocate memory, it will return %0. On success, it returns %1. - */ int ida_pre_get(struct ida *ida, gfp_t gfp) { /* @@ -2134,7 +2126,6 @@ int ida_pre_get(struct ida *ida, gfp_t gfp) return 1; } -EXPORT_SYMBOL(ida_pre_get); void __rcu **idr_get_free(struct radix_tree_root *root, struct radix_tree_iter *iter, gfp_t gfp, -- cgit v1.2.3-59-g8ed1b