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Enhance raw io reliability, by Ben Guthro.

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git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3166 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
ths 2007-09-13 12:29:23 +00:00
parent c3e88d8c4f
commit 8c05dbf9b6
1 changed files with 70 additions and 2 deletions
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72
block-raw.c
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@ -59,6 +59,13 @@
//#define DEBUG_FLOPPY
#define DEBUG_BLOCK
#if defined(DEBUG_BLOCK) && !defined(QEMU_TOOL)
#define DEBUG_BLOCK_PRINT(formatCstr, args...) fprintf(logfile, formatCstr, ##args); fflush(logfile)
#else
#define DEBUG_BLOCK_PRINT(formatCstr, args...)
#endif
#define FTYPE_FILE 0
#define FTYPE_CD 1
#define FTYPE_FD 2
@ -70,6 +77,7 @@
typedef struct BDRVRawState {
int fd;
int type;
unsigned int lseek_err_cnt;
#if defined(__linux__)
/* linux floppy specific */
int fd_open_flags;
@ -87,6 +95,8 @@ static int raw_open(BlockDriverState *bs, const char *filename, int flags)
BDRVRawState *s = bs->opaque;
int fd, open_flags, ret;
s->lseek_err_cnt = 0;
open_flags = O_BINARY;
if ((flags & BDRV_O_ACCESS) == O_RDWR) {
open_flags |= O_RDWR;
@ -137,8 +147,45 @@ static int raw_pread(BlockDriverState *bs, int64_t offset,
if (ret < 0)
return ret;
lseek(s->fd, offset, SEEK_SET);
if (lseek(s->fd, offset, SEEK_SET) == (off_t)-1) {
++(s->lseek_err_cnt);
if(s->lseek_err_cnt <= 10) {
DEBUG_BLOCK_PRINT("raw_pread(%d:%s, %lld, %p, %d) [%lld] lseek failed : %d = %s\n",
s->fd, bs->filename, offset, buf, count,
bs->total_sectors, errno, strerror(errno));
}
return -1;
}
s->lseek_err_cnt=0;
ret = read(s->fd, buf, count);
if (ret == count)
goto label__raw_read__success;
DEBUG_BLOCK_PRINT("raw_read(%d:%s, %lld, %p, %d) [%lld] read failed %d : %d = %s\n",
s->fd, bs->filename, offset, buf, count,
bs->total_sectors, ret, errno, strerror(errno));
/* Try harder for CDrom. */
if (bs->type == BDRV_TYPE_CDROM) {
lseek(s->fd, offset, SEEK_SET);
ret = read(s->fd, buf, count);
if (ret == count)
goto label__raw_read__success;
lseek(s->fd, offset, SEEK_SET);
ret = read(s->fd, buf, count);
if (ret == count)
goto label__raw_read__success;
DEBUG_BLOCK_PRINT("raw_read(%d:%s, %lld, %p, %d) [%lld] retry read failed %d : %d = %s\n",
s->fd, bs->filename, offset, buf, count,
bs->total_sectors, ret, errno, strerror(errno));
}
return -1;
label__raw_read__success:
return ret;
}
@ -152,8 +199,29 @@ static int raw_pwrite(BlockDriverState *bs, int64_t offset,
if (ret < 0)
return ret;
lseek(s->fd, offset, SEEK_SET);
if (lseek(s->fd, offset, SEEK_SET) == (off_t)-1) {
++(s->lseek_err_cnt);
if(s->lseek_err_cnt) {
DEBUG_BLOCK_PRINT("raw_write(%d:%s, %lld, %p, %d) [%lld] lseek failed : %d = %s\n",
s->fd, bs->filename, offset, buf, count,
bs->total_sectors, errno, strerror(errno));
}
return -1;
}
s->lseek_err_cnt = 0;
ret = write(s->fd, buf, count);
if (ret == count)
goto label__raw_write__success;
DEBUG_BLOCK_PRINT("raw_write(%d:%s, %lld, %p, %d) [%lld] write failed %d : %d = %s\n",
s->fd, bs->filename, offset, buf, count,
bs->total_sectors, ret, errno, strerror(errno));
return -1;
label__raw_write__success:
return ret;
}