1BIO_ALLOC(9)                     The Linux VFS                    BIO_ALLOC(9)
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NAME

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

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

12       gfp_mask
13           allocation mask to use
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15       nr_iovecs
16           number of iovecs
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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.
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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.
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RETURNS

31       Pointer to new bio on success, NULL on failure.
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34Kernel Hackers Manual 2.6.         June 2019                      BIO_ALLOC(9)
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