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author | Lennart Poettering <lennart@poettering.net> | 2022-09-01 15:00:30 +0200 |
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committer | Lennart Poettering <lennart@poettering.net> | 2022-09-01 22:05:32 +0200 |
commit | 7f52206a2bc128f9ae8306db43aa6e2f7d916f82 (patch) | |
tree | 71abcc3bae9c57aa3ceb041e2a3cfea0c193c95b /src/nspawn | |
parent | 234c2e16e5686d1a49fe84e534d4edb2db8d3719 (diff) | |
download | systemd-7f52206a2bc128f9ae8306db43aa6e2f7d916f82.tar.gz |
loop-util: rework how we lock loopback block devices
Let's rework how we lock loopback block devices in two ways:
1. Lock a separate fd, instead of the main block device fd. We already
did that for our internal locking when allocating loopback block
devices, but do so for the exposed locking (i.e.
loop_device_flock()), too, so that the lock is independent of the
main fd we actually use of IO.
2. Instead of locking the device during allocation of the loopback
device, then unlocking it (which will make udev run), and then
re-locking things if we need, let's instead just keep the lock the
whole time, to make things a bit safer and faster, and not have to
wait for udev at all. This is done by adding a "lock_op" parameter to
loop device allocation functions that declares the initial state of
the lock, and is one of LOCK_UN/LOCK_SH/LOCK_EX. This change also
shortens a lot of code, since we allocate + immediately lock loopback
devices pretty much everywhere.
Diffstat (limited to 'src/nspawn')
-rw-r--r-- | src/nspawn/nspawn.c | 8 |
1 files changed, 1 insertions, 7 deletions
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c index 75af4c58f9..45e138d48a 100644 --- a/src/nspawn/nspawn.c +++ b/src/nspawn/nspawn.c @@ -5746,19 +5746,13 @@ static int run(int argc, char *argv[]) { arg_image, arg_read_only ? O_RDONLY : O_RDWR, FLAGS_SET(dissect_image_flags, DISSECT_IMAGE_NO_PARTITION_TABLE) ? 0 : LO_FLAGS_PARTSCAN, + LOCK_SH, &loop); if (r < 0) { log_error_errno(r, "Failed to set up loopback block device: %m"); goto finish; } - /* Take a LOCK_SH lock on the device, so that udevd doesn't issue BLKRRPART in our back */ - r = loop_device_flock(loop, LOCK_SH); - if (r < 0) { - log_error_errno(r, "Failed to take lock on loopback block device: %m"); - goto finish; - } - r = dissect_image_and_warn( loop->fd, arg_image, |