Author: tsoome Date: Thu Nov 2 08:47:03 2017 New Revision: 325310 URL: https://svnweb.freebsd.org/changeset/base/325310
Log: zfs.c:vdev_read() needs to be careful about large sectors Using the same implementation as done in efi/boot1. We must handle smaller than sector size IO etc. Differential Revision: https://reviews.freebsd.org/D12850 Modified: head/sys/boot/zfs/zfs.c Modified: head/sys/boot/zfs/zfs.c ============================================================================== --- head/sys/boot/zfs/zfs.c Thu Nov 2 07:25:59 2017 (r325309) +++ head/sys/boot/zfs/zfs.c Thu Nov 2 08:47:03 2017 (r325310) @@ -368,17 +368,61 @@ zfs_readdir(struct open_file *f, struct dirent *d) } static int -vdev_read(vdev_t *vdev, void *priv, off_t offset, void *buf, size_t size) +vdev_read(vdev_t *vdev, void *priv, off_t offset, void *buf, size_t bytes) { - int fd; + int fd, ret; + size_t res, size, remainder, rb_size, blksz; + unsigned secsz; + off_t off; + char *bouncebuf, *rb_buf; fd = (uintptr_t) priv; - lseek(fd, offset, SEEK_SET); - if (read(fd, buf, size) == size) { - return 0; - } else { - return (EIO); + 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); + 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) { + 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; + } + + ret = 0; +error: + if (bouncebuf != NULL) + zfs_free(bouncebuf, secsz); + return (ret); } static int _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
