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a0f326228a
This patch fixes two different bugs in v9fs_reclaim_fd():
1. Reduce latency:
This function calls v9fs_co_close() and v9fs_co_closedir() in a loop. Each
one of the calls adds two thread hops (between main thread and a fs driver
background thread). Each thread hop adds latency, which sums up in
function's loop to a significant duration.
Reduce overall latency by open coding what v9fs_co_close() and
v9fs_co_closedir() do, executing those and the loop itself altogether in
only one background thread block, hence reducing the total amount of
thread hops to only two.
2. Fix file descriptor leak:
The existing code called v9fs_co_close() and v9fs_co_closedir() to close
file descriptors. Both functions check right at the beginning if the 9p
request was cancelled:
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
So if client sent a 'Tflush' message, v9fs_co_close() / v9fs_co_closedir()
returned without having closed the file descriptor and v9fs_reclaim_fd()
subsequently freed the FID without its file descriptor being closed, hence
leaking those file descriptors.
This 2nd bug is fixed by this patch as well by open coding v9fs_co_close()
and v9fs_co_closedir() inside of v9fs_reclaim_fd() and not performing the
v9fs_request_cancelled(pdu) check there.
Fixes:
|
||
|---|---|---|
| .. | ||
| 9p-local.c | ||
| 9p-local.h | ||
| 9p-posix-acl.c | ||
| 9p-synth.c | ||
| 9p-synth.h | ||
| 9p-util-darwin.c | ||
| 9p-util-generic.c | ||
| 9p-util-linux.c | ||
| 9p-util.h | ||
| 9p-xattr-user.c | ||
| 9p-xattr.c | ||
| 9p-xattr.h | ||
| 9p.c | ||
| 9p.h | ||
| codir.c | ||
| cofile.c | ||
| cofs.c | ||
| coth.c | ||
| coth.h | ||
| coxattr.c | ||
| Kconfig | ||
| meson.build | ||
| trace-events | ||
| trace.h | ||
| virtio-9p-device.c | ||
| virtio-9p.h | ||
| xen-9p-backend.c | ||
| xen-9pfs.h | ||