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Add XXX'ed temporary bounce-buffering.

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This commit is contained in:
Poul-Henning Kamp 2003-10-07 07:12:22 +00:00
parent a1721d84eb
commit ed1eac71f4
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=120874
1 changed files with 37 additions and 6 deletions
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43
lib/libufs/block.c
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@ -40,6 +40,7 @@ __FBSDID("$FreeBSD$");
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
@ -48,17 +49,24 @@ __FBSDID("$FreeBSD$");
ssize_t
bread(struct uufsd *disk, ufs2_daddr_t blockno, void *data, size_t size)
{
char *buf;
void *p2;
ssize_t cnt;
ERROR(disk, NULL);
p2 = data;
/*
* For when we need to work with the data as a buffer.
* XXX: various disk controllers require alignment of our buffer
* XXX: which is stricter than struct alignment.
* XXX: Bounce the buffer if not 64 byte aligned.
* XXX: this can be removed if/when the kernel is fixed
*/
buf = data;
cnt = pread(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
if (((intptr_t)data) & 0x3f) {
p2 = malloc(size);
if (p2 == NULL)
ERROR(disk, "allocate bounce buffer");
}
cnt = pread(disk->d_fd, p2, size, (off_t)(blockno * disk->d_bsize));
if (cnt == -1) {
ERROR(disk, "read error from block device");
goto fail;
@ -71,8 +79,15 @@ bread(struct uufsd *disk, ufs2_daddr_t blockno, void *data, size_t size)
ERROR(disk, "short read or read error from block device");
goto fail;
}
if (p2 != data) {
memcpy(data, p2, size);
free(p2);
}
return (cnt);
fail: memset(buf, 0, size);
fail: memset(data, 0, size);
if (p2 != data) {
free(p2);
}
return (-1);
}
@ -81,6 +96,7 @@ bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
{
ssize_t cnt;
int rv;
void *p2 = NULL;
ERROR(disk, NULL);
@ -90,7 +106,22 @@ bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
return (-1);
}
/*
* XXX: various disk controllers require alignment of our buffer
* XXX: which is stricter than struct alignment.
* XXX: Bounce the buffer if not 64 byte aligned.
* XXX: this can be removed if/when the kernel is fixed
*/
if (((intptr_t)data) & 0x3f) {
p2 = malloc(size);
if (p2 == NULL)
ERROR(disk, "allocate bounce buffer");
memcpy(p2, data, size);
data = p2;
}
cnt = pwrite(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
if (p2 != NULL)
free(p2);
if (cnt == -1) {
ERROR(disk, "write error to block device");
return (-1);