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33336c1805
When qgroups are enabled, during data reservation, we allocate the ulist_nodes that track the exact reserved extents with GFP_ATOMIC unconditionally. This is unnecessary, and we can follow the model already employed by the struct extent_state we preallocate in the non qgroups case, which should reduce the risk of allocation failures with GFP_ATOMIC. Add a prealloc node to struct ulist which ulist_add will grab when it is present, and try to allocate it before taking the tree lock while we can still take advantage of a less strict gfp mask. The lifetime of that node belongs to the new prealloc field, until it is used, at which point it belongs to the ulist linked list. Reviewed-by: Qu Wenruo <wqu@suse.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Boris Burkov <boris@bur.io> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
77 lines
2 KiB
C
77 lines
2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 2011 STRATO AG
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* written by Arne Jansen <sensille@gmx.net>
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*/
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#ifndef BTRFS_ULIST_H
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#define BTRFS_ULIST_H
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#include <linux/types.h>
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#include <linux/list.h>
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#include <linux/rbtree.h>
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/*
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* ulist is a generic data structure to hold a collection of unique u64
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* values. The only operations it supports is adding to the list and
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* enumerating it.
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* It is possible to store an auxiliary value along with the key.
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*
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*/
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struct ulist_iterator {
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struct list_head *cur_list; /* hint to start search */
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};
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/*
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* element of the list
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*/
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struct ulist_node {
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u64 val; /* value to store */
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u64 aux; /* auxiliary value saved along with the val */
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struct list_head list; /* used to link node */
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struct rb_node rb_node; /* used to speed up search */
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};
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struct ulist {
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/*
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* number of elements stored in list
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*/
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unsigned long nnodes;
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struct list_head nodes;
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struct rb_root root;
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struct ulist_node *prealloc;
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};
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void ulist_init(struct ulist *ulist);
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void ulist_release(struct ulist *ulist);
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void ulist_reinit(struct ulist *ulist);
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struct ulist *ulist_alloc(gfp_t gfp_mask);
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void ulist_prealloc(struct ulist *ulist, gfp_t mask);
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void ulist_free(struct ulist *ulist);
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int ulist_add(struct ulist *ulist, u64 val, u64 aux, gfp_t gfp_mask);
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int ulist_add_merge(struct ulist *ulist, u64 val, u64 aux,
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u64 *old_aux, gfp_t gfp_mask);
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int ulist_del(struct ulist *ulist, u64 val, u64 aux);
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/* just like ulist_add_merge() but take a pointer for the aux data */
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static inline int ulist_add_merge_ptr(struct ulist *ulist, u64 val, void *aux,
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void **old_aux, gfp_t gfp_mask)
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{
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#if BITS_PER_LONG == 32
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u64 old64 = (uintptr_t)*old_aux;
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int ret = ulist_add_merge(ulist, val, (uintptr_t)aux, &old64, gfp_mask);
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*old_aux = (void *)((uintptr_t)old64);
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return ret;
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#else
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return ulist_add_merge(ulist, val, (u64)aux, (u64 *)old_aux, gfp_mask);
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#endif
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}
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struct ulist_node *ulist_next(const struct ulist *ulist,
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struct ulist_iterator *uiter);
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#define ULIST_ITER_INIT(uiter) ((uiter)->cur_list = NULL)
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#endif
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