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struct ceph_buffer is a simple ref-counted buffer. We transparently choose between kmalloc for small buffers and vmalloc for large ones. This is currently used only for allocating memory for xattr data. Signed-off-by: Sage Weil <sage@newdream.net>
56 lines
1.0 KiB
C
56 lines
1.0 KiB
C
#ifndef __FS_CEPH_BUFFER_H
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#define __FS_CEPH_BUFFER_H
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#include <linux/mm.h>
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#include <linux/vmalloc.h>
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#include <linux/types.h>
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#include <linux/uio.h>
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/*
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* a simple reference counted buffer.
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*
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* use kmalloc for small sizes (<= one page), vmalloc for larger
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* sizes.
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*/
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struct ceph_buffer {
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atomic_t nref;
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struct kvec vec;
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size_t alloc_len;
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bool is_vmalloc;
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};
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struct ceph_buffer *ceph_buffer_new(gfp_t gfp);
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int ceph_buffer_alloc(struct ceph_buffer *b, int len, gfp_t gfp);
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static inline struct ceph_buffer *ceph_buffer_get(struct ceph_buffer *b)
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{
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atomic_inc(&b->nref);
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return b;
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}
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static inline void ceph_buffer_put(struct ceph_buffer *b)
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{
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if (b && atomic_dec_and_test(&b->nref)) {
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if (b->vec.iov_base) {
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if (b->is_vmalloc)
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vfree(b->vec.iov_base);
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else
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kfree(b->vec.iov_base);
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}
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kfree(b);
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}
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}
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static inline struct ceph_buffer *ceph_buffer_new_alloc(int len, gfp_t gfp)
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{
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struct ceph_buffer *b = ceph_buffer_new(gfp);
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if (b && ceph_buffer_alloc(b, len, gfp) < 0) {
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ceph_buffer_put(b);
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b = NULL;
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}
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return b;
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}
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#endif
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