diff options
| -rw-r--r-- | usr/src/boot/Makefile.version | 2 | ||||
| -rw-r--r-- | usr/src/boot/lib/libstand/zfs/zfs.c | 110 |
2 files changed, 81 insertions, 31 deletions
diff --git a/usr/src/boot/Makefile.version b/usr/src/boot/Makefile.version index a161b24487..46e00fbcea 100644 --- a/usr/src/boot/Makefile.version +++ b/usr/src/boot/Makefile.version @@ -33,4 +33,4 @@ LOADER_VERSION = 1.1 # Use date like formatting here, YYYY.MM.DD.XX, without leading zeroes. # The version is processed from left to right, the version number can only # be increased. -BOOT_VERSION = $(LOADER_VERSION)-2019.11.05.1 +BOOT_VERSION = $(LOADER_VERSION)-2019.11.06.1 diff --git a/usr/src/boot/lib/libstand/zfs/zfs.c b/usr/src/boot/lib/libstand/zfs/zfs.c index e76f1ada52..665d0b4a48 100644 --- a/usr/src/boot/lib/libstand/zfs/zfs.c +++ b/usr/src/boot/lib/libstand/zfs/zfs.c @@ -347,57 +347,107 @@ vdev_read(vdev_t *vdev __unused, void *priv, off_t offset, void *buf, size_t bytes) { int fd, ret; - size_t res, size, remainder, rb_size, blksz; - unsigned secsz; - off_t off; - char *bouncebuf, *rb_buf; + size_t res, head, tail, total_size, full_sec_size; + unsigned secsz, do_tail_read; + off_t start_sec; + char *outbuf, *bouncebuf; fd = (uintptr_t)priv; + outbuf = (char *)buf; bouncebuf = NULL; ret = ioctl(fd, DIOCGSECTORSIZE, &secsz); if (ret != 0) return (ret); - off = offset / secsz; - remainder = offset % secsz; - if (lseek(fd, off * secsz, SEEK_SET) == -1) - return (errno); - - rb_buf = buf; - rb_size = bytes; - size = roundup2(bytes + remainder, secsz); - blksz = size; - if (remainder != 0 || size != bytes) { - bouncebuf = zfs_alloc(secsz); + /* + * Handling reads of arbitrary offset and size - multi-sector case + * and single-sector case. + * + * Multi-sector Case + * (do_tail_read = true if tail > 0) + * + * |<----------------------total_size--------------------->| + * | | + * |<--head-->|<--------------bytes------------>|<--tail-->| + * | | | | + * | | |<~full_sec_size~>| | | + * +------------------+ +------------------+ + * | |0101010| . . . |0101011| | + * +------------------+ +------------------+ + * start_sec start_sec + n + * + * + * Single-sector Case + * (do_tail_read = false) + * + * |<------total_size = secsz----->| + * | | + * |<-head->|<---bytes--->|<-tail->| + * +-------------------------------+ + * | |0101010101010| | + * +-------------------------------+ + * start_sec + */ + start_sec = offset / secsz; + head = offset % secsz; + total_size = roundup2(head + bytes, secsz); + tail = total_size - (head + bytes); + do_tail_read = ((tail > 0) && (head + bytes > secsz)); + full_sec_size = total_size; + if (head > 0) + full_sec_size -= secsz; + if (do_tail_read) + full_sec_size -= secsz; + + /* Return of partial sector data requires a bounce buffer. */ + if ((head > 0) || do_tail_read) { + bouncebuf = malloc(secsz); if (bouncebuf == NULL) { printf("vdev_read: out of memory\n"); return (ENOMEM); } - rb_buf = bouncebuf; - blksz = rb_size - remainder; } - while (bytes > 0) { - res = read(fd, rb_buf, rb_size); - if (res != rb_size) { + if (lseek(fd, start_sec * secsz, SEEK_SET) == -1) { + ret = errno; + goto error; + } + + /* Partial data return from first sector */ + if (head > 0) { + res = read(fd, bouncebuf, secsz); + if (res != secsz) { + ret = EIO; + goto error; + } + memcpy(outbuf, bouncebuf + head, min(secsz - head, bytes)); + outbuf += min(secsz - head, bytes); + } + + /* Full data return from read sectors */ + if (full_sec_size > 0) { + res = read(fd, outbuf, full_sec_size); + if (res != full_sec_size) { + ret = EIO; + goto error; + } + outbuf += full_sec_size; + } + + /* Partial data return from last sector */ + if (do_tail_read) { + res = read(fd, bouncebuf, secsz); + if (res != secsz) { ret = EIO; goto error; } - if (bytes < blksz) - blksz = bytes; - if (bouncebuf != NULL) - memcpy(buf, rb_buf + remainder, blksz); - buf = (void *)((uintptr_t)buf + blksz); - bytes -= blksz; - remainder = 0; - blksz = rb_size; + memcpy(outbuf, bouncebuf, secsz - tail); } ret = 0; error: - if (bouncebuf != NULL) - zfs_free(bouncebuf, secsz); + free(bouncebuf); return (ret); } |