1BIO_ALLOC(9)                     The Linux VFS                    BIO_ALLOC(9)
2
3
4

NAME

6       bio_alloc - allocate a new bio, memory pool backed
7

SYNOPSIS

9       struct bio * bio_alloc(gfp_t gfp_mask, int nr_iovecs);
10

ARGUMENTS

12       gfp_mask
13           allocation mask to use
14
15       nr_iovecs
16           number of iovecs
17

DESCRIPTION

19       bio_alloc will allocate a bio and associated bio_vec array that can
20       hold at least nr_iovecs entries. Allocations will be done from the
21       fs_bio_set. Also see bio_alloc_bioset and bio_kmalloc.
22
23       If __GFP_WAIT is set, then bio_alloc will always be able to allocate a
24       bio. This is due to the mempool guarantees. To make this work, callers
25       must never allocate more than 1 bio at a time from this pool. Callers
26       that need to allocate more than 1 bio must always submit the previously
27       allocated bio for IO before attempting to allocate a new one. Failure
28       to do so can cause livelocks under memory pressure.
29

RETURNS

31       Pointer to new bio on success, NULL on failure.
32

34Kernel Hackers Manual 2.6.       November 2011                    BIO_ALLOC(9)
Impressum