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Added fcntl() locking to O_EXCL locking

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This commit is contained in:
Thomas Schmitt 2007-04-03 14:04:04 +00:00
parent 15b33422d0
commit 16c7cf1889
2 changed files with 73 additions and 29 deletions
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2
cdrskin/cdrskin_timestamp.h
View File

@ -1 +1 @@
#define Cdrskin_timestamP "2007.03.30.214657" #define Cdrskin_timestamP "2007.04.03.140356"

100
libburn/sg-linux.c
View File

@ -267,6 +267,75 @@ static int sg_handle_busy_device(char *fname, int os_errno)
} }
/* ts A60925 : ticket 74 */
static int sg_close_drive_fd(char *fname, int driveno, int *fd, int sorry)
{
int ret, os_errno, sevno= LIBDAX_MSGS_SEV_DEBUG;
char msg[4096+100];
if(*fd < 0)
return(0);
ret = close(*fd);
*fd = -1337;
if(ret != -1)
return 1;
os_errno= errno;
if (fname != NULL)
sprintf(msg, "Encountered error when closing drive '%s'",
fname);
else
sprintf(msg, "Encountered error when closing drive");
if (sorry)
sevno = LIBDAX_MSGS_SEV_SORRY;
libdax_msgs_submit(libdax_messenger, driveno, 0x00020002,
sevno, LIBDAX_MSGS_PRIO_HIGH, msg, os_errno, 0);
return 0;
}
/* ts A70401 :
In http://lkml.org/lkml/2007/3/31/187 , Alan Cox demands usage of
SG_IO on block devices and of fcntl rather than O_EXCL.
fcntl() has the unappealing property to work only after open().
So libburn will by default use open(O_EXCL) first and afterwards
as second assertion will use fcntl(F_SETLK).
*/
int sg_fcntl_lock(int *fd, char *fd_name)
{
#define Libburn_sg_with_fcntl_locK 1
#ifdef Libburn_sg_with_fcntl_locK
struct flock lockthing;
char msg[81];
int ret;
memset(&lockthing, 0, sizeof(lockthing));
lockthing.l_type = F_WRLCK;
lockthing.l_whence = SEEK_SET;
lockthing.l_start = 0;
lockthing.l_len = 0;
/*
fprintf(stderr,"LIBBURN_EXPERIMENTAL: fcntl(%d, F_SETLK, )\n", *fd);
*/
ret = fcntl(*fd, F_SETLK, &lockthing);
if (ret == -1) {
sprintf(msg, "Failed to fcntl-lock device '%s'",fd_name);
libdax_msgs_submit(libdax_messenger, -1, 0x00020005,
LIBDAX_MSGS_SEV_FATAL, LIBDAX_MSGS_PRIO_HIGH,
msg, errno, 0);
close(*fd);
*fd = -1;
return(0);
}
#endif /* Libburn_sg_with_fcntl_locK */
return(1);
}
/* ts A60926 */ /* ts A60926 */
static int sg_open_drive_fd(char *fname, int scan_mode) static int sg_open_drive_fd(char *fname, int scan_mode)
{ {
@ -315,38 +384,11 @@ static int sg_open_drive_fd(char *fname, int scan_mode)
msg, errno, 0); msg, errno, 0);
return -1; return -1;
} }
sg_fcntl_lock(&fd, fname);
return fd; return fd;
} }
/* ts A60925 : ticket 74 */
static int sg_close_drive_fd(char *fname, int driveno, int *fd, int sorry)
{
int ret, os_errno, sevno= LIBDAX_MSGS_SEV_DEBUG;
char msg[4096+100];
if(*fd < 0)
return(0);
ret = close(*fd);
*fd = -1337;
if(ret != -1)
return 1;
os_errno= errno;
if (fname != NULL)
sprintf(msg, "Encountered error when closing drive '%s'",
fname);
else
sprintf(msg, "Encountered error when closing drive");
if (sorry)
sevno = LIBDAX_MSGS_SEV_SORRY;
libdax_msgs_submit(libdax_messenger, driveno, 0x00020002,
sevno, LIBDAX_MSGS_PRIO_HIGH, msg, os_errno, 0);
return 0;
}
/* ts A60926 */ /* ts A60926 */
static int sg_release_siblings(int sibling_fds[], int *sibling_count) static int sg_release_siblings(int sibling_fds[], int *sibling_count)
{ {
@ -873,6 +915,8 @@ int sg_grab(struct burn_drive *d)
fd = open(d->devname, open_mode); fd = open(d->devname, open_mode);
os_errno = errno; os_errno = errno;
if (fd >= 0)
sg_fcntl_lock(&fd, d->devname);
} else } else
fd= d->fd; fd= d->fd;