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Optimize zpool_read_all_labels with AIO

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Read all labels in parallel instead of sequentially

MFC after:	3 weeks
X-MFC-With: 322854
Sponsored by:	Spectra Logic Corp
Differential Revision:	https://reviews.freebsd.org/D12495
This commit is contained in:
asomers 2017-10-12 21:25:11 +00:00
parent 73beed95a9
commit c49a19fd7c
1 changed files with 33 additions and 8 deletions
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41
cddl/contrib/opensolaris/lib/libzfs/common/libzfs_import.c
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@ -42,6 +42,7 @@
* using our derived config, and record the results.
*/
#include <aio.h>
#include <ctype.h>
#include <devid.h>
#include <dirent.h>
@ -919,13 +920,17 @@ zpool_read_label(int fd, nvlist_t **config)
* Given a file descriptor, read the label information and return an nvlist
* describing the configuration, if there is one.
* returns the number of valid labels found
* If a label is found, returns it via config. The caller is responsible for
* freeing it.
*/
int
zpool_read_all_labels(int fd, nvlist_t **config)
{
struct stat64 statbuf;
struct aiocb aiocbs[VDEV_LABELS];
struct aiocb *aiocbps[VDEV_LABELS];
int l;
vdev_label_t *label;
vdev_label_t *labels;
uint64_t state, txg, size;
int nlabels = 0;
@ -935,19 +940,39 @@ zpool_read_all_labels(int fd, nvlist_t **config)
return (0);
size = P2ALIGN_TYPED(statbuf.st_size, sizeof (vdev_label_t), uint64_t);
if ((label = malloc(sizeof (vdev_label_t))) == NULL)
if ((labels = calloc(VDEV_LABELS, sizeof (vdev_label_t))) == NULL)
return (0);
memset(aiocbs, 0, sizeof(aiocbs));
for (l = 0; l < VDEV_LABELS; l++) {
aiocbs[l].aio_fildes = fd;
aiocbs[l].aio_offset = label_offset(size, l);
aiocbs[l].aio_buf = &labels[l];
aiocbs[l].aio_nbytes = sizeof(vdev_label_t);
aiocbs[l].aio_lio_opcode = LIO_READ;
aiocbps[l] = &aiocbs[l];
}
if (lio_listio(LIO_WAIT, aiocbps, VDEV_LABELS, NULL) != 0) {
if (errno == EAGAIN || errno == EINTR || errno == EIO) {
for (l = 0; l < VDEV_LABELS; l++) {
errno = 0;
int r = aio_error(&aiocbs[l]);
if (r != EINVAL)
(void)aio_return(&aiocbs[l]);
}
}
return (0);
}
for (l = 0; l < VDEV_LABELS; l++) {
nvlist_t *temp = NULL;
/* TODO: use aio_read so we can read al 4 labels in parallel */
if (pread64(fd, label, sizeof (vdev_label_t),
label_offset(size, l)) != sizeof (vdev_label_t))
if (aio_return(&aiocbs[l]) != sizeof(vdev_label_t))
continue;
if (nvlist_unpack(label->vl_vdev_phys.vp_nvlist,
sizeof (label->vl_vdev_phys.vp_nvlist), &temp, 0) != 0)
if (nvlist_unpack(labels[l].vl_vdev_phys.vp_nvlist,
sizeof (labels[l].vl_vdev_phys.vp_nvlist), &temp, 0) != 0)
continue;
if (nvlist_lookup_uint64(temp, ZPOOL_CONFIG_POOL_STATE,
@ -970,7 +995,7 @@ zpool_read_all_labels(int fd, nvlist_t **config)
nlabels++;
}
free(label);
free(labels);
return (nlabels);
}