diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/block/block_int.h | 37 |
1 files changed, 20 insertions, 17 deletions
diff --git a/include/block/block_int.h b/include/block/block_int.h index 1fe0fd9ff6..47665be81e 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -330,36 +330,39 @@ typedef struct BlockLimits { * otherwise. */ uint32_t request_alignment; - /* maximum number of bytes that can be discarded at once (since it - * is signed, it must be < 2G, if set), should be multiple of + /* Maximum number of bytes that can be discarded at once (since it + * is signed, it must be < 2G, if set). Must be multiple of * pdiscard_alignment, but need not be power of 2. May be 0 if no * inherent 32-bit limit */ int32_t max_pdiscard; - /* optimal alignment for discard requests in bytes, must be power - * of 2, less than max_pdiscard if that is set, and multiple of - * bl.request_alignment. May be 0 if bl.request_alignment is good - * enough */ + /* Optimal alignment for discard requests in bytes. A power of 2 + * is best but not mandatory. Must be a multiple of + * bl.request_alignment, and must be less than max_pdiscard if + * that is set. May be 0 if bl.request_alignment is good enough */ uint32_t pdiscard_alignment; - /* maximum number of bytes that can zeroized at once (since it is - * signed, it must be < 2G, if set), should be multiple of + /* Maximum number of bytes that can zeroized at once (since it is + * signed, it must be < 2G, if set). Must be multiple of * pwrite_zeroes_alignment. May be 0 if no inherent 32-bit limit */ int32_t max_pwrite_zeroes; - /* optimal alignment for write zeroes requests in bytes, must be - * power of 2, less than max_pwrite_zeroes if that is set, and - * multiple of bl.request_alignment. May be 0 if - * bl.request_alignment is good enough */ + /* Optimal alignment for write zeroes requests in bytes. A power + * of 2 is best but not mandatory. Must be a multiple of + * bl.request_alignment, and must be less than max_pwrite_zeroes + * if that is set. May be 0 if bl.request_alignment is good + * enough */ uint32_t pwrite_zeroes_alignment; - /* optimal transfer length in bytes (must be power of 2, and - * multiple of bl.request_alignment), or 0 if no preferred size */ + /* Optimal transfer length in bytes. A power of 2 is best but not + * mandatory. Must be a multiple of bl.request_alignment, or 0 if + * no preferred size */ uint32_t opt_transfer; - /* maximal transfer length in bytes (need not be power of 2, but - * should be multiple of opt_transfer), or 0 for no 32-bit limit. - * For now, anything larger than INT_MAX is clamped down. */ + /* Maximal transfer length in bytes. Need not be power of 2, but + * must be multiple of opt_transfer and bl.request_alignment, or 0 + * for no 32-bit limit. For now, anything larger than INT_MAX is + * clamped down. */ uint32_t max_transfer; /* memory alignment, in bytes so that no bounce buffer is needed */ |