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[Qemu-devel] [PATCH v3 14/44] sd: Switch to byte-based block access
From: |
Eric Blake |
Subject: |
[Qemu-devel] [PATCH v3 14/44] sd: Switch to byte-based block access |
Date: |
Fri, 22 Apr 2016 17:40:22 -0600 |
Sector-based blk_write() should die; switch to byte-based
blk_pwrite() instead. Likewise for blk_read().
Greatly simplifies the code, now that we let the block layer
take care of alignment and read-modify-write on our behalf :)
Signed-off-by: Eric Blake <address@hidden>
---
hw/sd/sd.c | 46 +++-------------------------------------------
1 file changed, 3 insertions(+), 43 deletions(-)
diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index b66e5d2..3c2f2f1 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -1577,57 +1577,17 @@ send_response:
static void sd_blk_read(SDState *sd, uint64_t addr, uint32_t len)
{
- uint64_t end = addr + len;
-
DPRINTF("sd_blk_read: addr = 0x%08llx, len = %d\n",
(unsigned long long) addr, len);
- if (!sd->blk || blk_read(sd->blk, addr >> 9, sd->buf, 1) < 0) {
+ if (!sd->blk || blk_pread(sd->blk, addr, sd->data, len) < 0) {
fprintf(stderr, "sd_blk_read: read error on host side\n");
- return;
}
-
- if (end > (addr & ~511) + 512) {
- memcpy(sd->data, sd->buf + (addr & 511), 512 - (addr & 511));
-
- if (blk_read(sd->blk, end >> 9, sd->buf, 1) < 0) {
- fprintf(stderr, "sd_blk_read: read error on host side\n");
- return;
- }
- memcpy(sd->data + 512 - (addr & 511), sd->buf, end & 511);
- } else
- memcpy(sd->data, sd->buf + (addr & 511), len);
}
static void sd_blk_write(SDState *sd, uint64_t addr, uint32_t len)
{
- uint64_t end = addr + len;
-
- if ((addr & 511) || len < 512)
- if (!sd->blk || blk_read(sd->blk, addr >> 9, sd->buf, 1) < 0) {
- fprintf(stderr, "sd_blk_write: read error on host side\n");
- return;
- }
-
- if (end > (addr & ~511) + 512) {
- memcpy(sd->buf + (addr & 511), sd->data, 512 - (addr & 511));
- if (blk_write(sd->blk, addr >> 9, sd->buf, 1) < 0) {
- fprintf(stderr, "sd_blk_write: write error on host side\n");
- return;
- }
-
- if (blk_read(sd->blk, end >> 9, sd->buf, 1) < 0) {
- fprintf(stderr, "sd_blk_write: read error on host side\n");
- return;
- }
- memcpy(sd->buf, sd->data + 512 - (addr & 511), end & 511);
- if (blk_write(sd->blk, end >> 9, sd->buf, 1) < 0) {
- fprintf(stderr, "sd_blk_write: write error on host side\n");
- }
- } else {
- memcpy(sd->buf + (addr & 511), sd->data, len);
- if (!sd->blk || blk_write(sd->blk, addr >> 9, sd->buf, 1) < 0) {
- fprintf(stderr, "sd_blk_write: write error on host side\n");
- }
+ if (!sd->blk || blk_pwrite(sd->blk, addr, sd->buf, len, 0) < 0) {
+ fprintf(stderr, "sd_blk_write: write error on host side\n");
}
}
--
2.5.5
- [Qemu-devel] [PATCH v3 04/44] nbd: Reject unknown request flags, (continued)
- [Qemu-devel] [PATCH v3 04/44] nbd: Reject unknown request flags, Eric Blake, 2016/04/22
- [Qemu-devel] [PATCH v3 01/44] nbd: More debug typo fixes, use correct formats, Eric Blake, 2016/04/22
- [Qemu-devel] [PATCH v3 02/44] nbd: Quit server after any write error, Eric Blake, 2016/04/22
- [Qemu-devel] [PATCH v3 08/44] nbd: Add qemu-nbd -D for human-readable description, Eric Blake, 2016/04/22
- [Qemu-devel] [PATCH v3 07/44] nbd: Limit nbdflags to 16 bits, Eric Blake, 2016/04/22
- [Qemu-devel] [PATCH v3 10/44] fdc: Switch to byte-based block access, Eric Blake, 2016/04/22
- [Qemu-devel] [PATCH v3 15/44] m25p80: Switch to byte-based block access, Eric Blake, 2016/04/22
- [Qemu-devel] [PATCH v3 14/44] sd: Switch to byte-based block access,
Eric Blake <=
- [Qemu-devel] [PATCH v3 13/44] pflash: Switch to byte-based block access, Eric Blake, 2016/04/22
- [Qemu-devel] [PATCH v3 16/44] atapi: Switch to byte-based block access, Eric Blake, 2016/04/22
- [Qemu-devel] [PATCH v3 18/44] qemu-img: Switch to byte-based block access, Eric Blake, 2016/04/22
- [Qemu-devel] [PATCH v3 23/44] qemu-io: Add missing option documentation, Eric Blake, 2016/04/22
- [Qemu-devel] [PATCH v3 29/44] nbd: Avoid magic number for NBD max name size, Eric Blake, 2016/04/22
- [Qemu-devel] [PATCH v3 31/44] nbd: Share common reply-sending code in server, Eric Blake, 2016/04/22
- [Qemu-devel] [PATCH v3 06/44] nbd: Clean up ioctl handling of qemu-nbd -c, Eric Blake, 2016/04/22