/* Open a file for buffered I/O */
StreamHandle_t *
stream_open(const char *filename, const char *mode)
{
FD_t fd = INVALID_FD;
if (strcmp(mode, "r") == 0) {
fd = OS_OPEN(filename, O_RDONLY, 0);
} else if (strcmp(mode, "r+") == 0) {
fd = OS_OPEN(filename, O_RDWR, 0);
} else if (strcmp(mode, "w") == 0) {
fd = OS_OPEN(filename, O_WRONLY | O_TRUNC | O_CREAT, 0);
} else if (strcmp(mode, "w+") == 0) {
fd = OS_OPEN(filename, O_RDWR | O_TRUNC | O_CREAT, 0);
} else if (strcmp(mode, "a") == 0) {
fd = OS_OPEN(filename, O_WRONLY | O_APPEND | O_CREAT, 0);
} else if (strcmp(mode, "a+") == 0) {
fd = OS_OPEN(filename, O_RDWR | O_APPEND | O_CREAT, 0);
} else {
osi_Assert(FALSE); /* not implemented */
}
if (fd == INVALID_FD) {
return NULL;
}
return stream_fdopen(fd);
}
/**
* handle a single vol header as part of VWalkVolumeHeaders.
*
* @param[in] dp disk partition
* @param[in] volfunc function to call when a vol header is successfully read
* @param[in] name full path name to the .vol header
* @param[out] hdr header data read in from the .vol header
* @param[in] locked 1 if the partition headers are locked, 0 otherwise
* @param[in] rock the rock to pass to volfunc
*
* @return operation status
* @retval 0 success
* @retval -1 fatal error, stop scanning
* @retval 1 failed to read header
* @retval 2 volfunc callback indicated error after header read
*/
static int
_VHandleVolumeHeader(struct DiskPartition64 *dp, VWalkVolFunc volfunc,
const char *name, struct VolumeDiskHeader *hdr,
int locked, void *rock)
{
int error = 0;
FD_t fd;
if ((fd = OS_OPEN(name, O_RDONLY, 0)) == INVALID_FD
|| OS_READ(fd, hdr, sizeof(*hdr))
!= sizeof(*hdr)
|| hdr->stamp.magic != VOLUMEHEADERMAGIC) {
error = 1;
}
if (fd != INVALID_FD) {
OS_CLOSE(fd);
}
#ifdef AFSFS_DEMAND_ATTACH_FS
if (locked) {
VPartHeaderUnlock(dp);
}
#endif /* AFS_DEMAND_ATTACH_FS */
if (!error && volfunc) {
/* the volume header seems fine; call the caller-supplied
* 'we-found-a-volume-header' function */
int last = 1;
#ifdef AFS_DEMAND_ATTACH_FS
if (!locked) {
last = 0;
}
#endif /* AFS_DEMAND_ATTACH_FS */
error = (*volfunc) (dp, name, hdr, last, rock);
if (error < 0) {
return -1;
}
if (error) {
error = 2;
}
}
#ifdef AFS_DEMAND_ATTACH_FS
if (error && !locked) {
int code;
/* retry reading the volume header under the partition
* header lock, just to be safe and ensure we're not
* racing something rewriting the vol header */
code = VPartHeaderLock(dp, WRITE_LOCK);
if (code) {
Log("Error acquiring partition write lock when "
"looking at header %s\n", name);
return -1;
}
return _VHandleVolumeHeader(dp, volfunc, name, hdr, 1, rock);
}
#endif /* AFS_DEMAND_ATTACH_FS */
return error;
}
