Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
scatterlist: inline sg_next()
sg_next() is a short function called frequently in I/O paths. Define it
in the header file so it can be inlined into its callers.
Link: https://lkml.kernel.org/r/20250416160615.3571958-1-csander@purestorage.com
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
authored by
Caleb Sander Mateos
and committed by
Andrew Morton
8d1d4b53
7d9b0527
+22
-24
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-1
include/linux/scatterlist.h
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-1
include/linux/scatterlist.h
···
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}
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/**
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* sg_next - return the next scatterlist entry in a list
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* @sg: The current sg entry
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*
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* Description:
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* Usually the next entry will be @sg@ + 1, but if this sg element is part
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* of a chained scatterlist, it could jump to the start of a new
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* scatterlist array.
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*
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**/
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static inline struct scatterlist *sg_next(struct scatterlist *sg)
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{
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if (sg_is_last(sg))
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return NULL;
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sg++;
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if (unlikely(sg_is_chain(sg)))
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sg = sg_chain_ptr(sg);
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return sg;
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}
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/**
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* sg_assign_page - Assign a given page to an SG entry
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* @sg: SG entry
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* @page: The page
···
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int sg_nents(struct scatterlist *sg);
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int sg_nents_for_len(struct scatterlist *sg, u64 len);
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struct scatterlist *sg_next(struct scatterlist *);
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struct scatterlist *sg_last(struct scatterlist *s, unsigned int);
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void sg_init_table(struct scatterlist *, unsigned int);
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void sg_init_one(struct scatterlist *, const void *, unsigned int);
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lib/scatterlist.c
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lib/scatterlist.c
···
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#include <linux/folio_queue.h>
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/**
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* sg_next - return the next scatterlist entry in a list
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* @sg: The current sg entry
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*
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* Description:
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* Usually the next entry will be @sg@ + 1, but if this sg element is part
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* of a chained scatterlist, it could jump to the start of a new
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* scatterlist array.
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*
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**/
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struct scatterlist *sg_next(struct scatterlist *sg)
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{
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if (sg_is_last(sg))
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return NULL;
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sg++;
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if (unlikely(sg_is_chain(sg)))
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sg = sg_chain_ptr(sg);
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return sg;
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}
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EXPORT_SYMBOL(sg_next);
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/**
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* sg_nents - return total count of entries in scatterlist
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* @sg: The scatterlist
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*