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repart: always take BSD lock when whole block device is opened

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Fixes #27236.
This commit is contained in:
Yu Watanabe 2023-04-13 02:43:52 +09:00 committed by Lennart Poettering
parent 5d0fd36495
commit 37734dc677
1 changed files with 40 additions and 15 deletions
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55
src/partition/repart.c
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@ -1998,6 +1998,28 @@ static int derive_uuid(sd_id128_t base, const char *token, sd_id128_t *ret) {
return 0;
}
static int context_open_and_lock_backing_fd(Context *context, const char *node) {
_cleanup_close_ int fd = -EBADF;
assert(context);
assert(node);
if (context->backing_fd >= 0)
return 0;
fd = open(node, O_RDONLY|O_CLOEXEC);
if (fd < 0)
return log_error_errno(errno, "Failed to open device '%s': %m", node);
/* Tell udev not to interfere while we are processing the device */
if (flock(fd, arg_dry_run ? LOCK_SH : LOCK_EX) < 0)
return log_error_errno(errno, "Failed to lock device '%s': %m", node);
log_debug("Device %s opened and locked.", node);
context->backing_fd = TAKE_FD(fd);
return 1;
}
static int context_load_partition_table(Context *context) {
_cleanup_(fdisk_unref_contextp) struct fdisk_context *c = NULL;
_cleanup_(fdisk_unref_tablep) struct fdisk_table *t = NULL;
@ -2026,11 +2048,9 @@ static int context_load_partition_table(Context *context) {
else {
uint32_t ssz;
if (context->backing_fd < 0) {
context->backing_fd = open(context->node, O_RDONLY|O_CLOEXEC);
if (context->backing_fd < 0)
return log_error_errno(errno, "Failed to open device '%s': %m", context->node);
}
r = context_open_and_lock_backing_fd(context, context->node);
if (r < 0)
return r;
/* Auto-detect sector size if not specified. */
r = probe_sector_size_prefer_ioctl(context->backing_fd, &ssz);
@ -2075,13 +2095,9 @@ static int context_load_partition_table(Context *context) {
if (context->backing_fd < 0) {
/* If we have no fd referencing the device yet, make a copy of the fd now, so that we have one */
context->backing_fd = fd_reopen(fdisk_get_devfd(c), O_RDONLY|O_CLOEXEC);
if (context->backing_fd < 0)
return log_error_errno(context->backing_fd, "Failed to duplicate fdisk fd: %m");
/* Tell udev not to interfere while we are processing the device */
if (flock(context->backing_fd, arg_dry_run ? LOCK_SH : LOCK_EX) < 0)
return log_error_errno(errno, "Failed to lock block device: %m");
r = context_open_and_lock_backing_fd(context, FORMAT_PROC_FD_PATH(fdisk_get_devfd(c)));
if (r < 0)
return r;
}
/* The offsets/sizes libfdisk returns to us will be in multiple of the sector size of the
@ -6198,7 +6214,7 @@ static int acquire_root_devno(
char **ret,
int *ret_fd) {
_cleanup_free_ char *found_path = NULL;
_cleanup_free_ char *found_path = NULL, *node = NULL;
dev_t devno, fd_devno = MODE_INVALID;
_cleanup_close_ int fd = -EBADF;
struct stat st;
@ -6253,13 +6269,22 @@ static int acquire_root_devno(
if (r < 0)
log_debug_errno(r, "Failed to find whole disk block device for '%s', ignoring: %m", p);
r = devname_from_devnum(S_IFBLK, devno, ret);
r = devname_from_devnum(S_IFBLK, devno, &node);
if (r < 0)
return log_debug_errno(r, "Failed to determine canonical path for '%s': %m", p);
/* Only if we still look at the same block device we can reuse the fd. Otherwise return an
* invalidated fd. */
*ret_fd = fd_devno != MODE_INVALID && fd_devno == devno ? TAKE_FD(fd) : -1;
if (fd_devno != MODE_INVALID && fd_devno == devno) {
/* Tell udev not to interfere while we are processing the device */
if (flock(fd, arg_dry_run ? LOCK_SH : LOCK_EX) < 0)
return log_error_errno(errno, "Failed to lock device '%s': %m", node);
*ret_fd = TAKE_FD(fd);
} else
*ret_fd = -EBADF;
*ret = TAKE_PTR(node);
return 0;
}