According to 'man 2 close' errors returned by close() should only be used
for either diagnostic purposes or for catching data loss due to a previous
write error, as an error result of close() usually indicates a deferred
error of a previous write operation.
Therefore not decrementing 'total_open_fd' on a close() error is wrong
and would yield in a higher open file descriptor count than actually the
case, leading to 9p server reclaiming open file descriptors too soon.
Based-on: <20250312152933.383967-7-gr...@kaod.org>
Signed-off-by: Christian Schoenebeck <qemu_...@crudebyte.com>
---
hw/9pfs/9p.c | 14 ++++++++------
hw/9pfs/codir.c | 3 ++-
hw/9pfs/cofile.c | 3 ++-
3 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index b22df3aa2b..f4ca8e4db5 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -434,7 +434,6 @@ void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu)
V9fsFidState *f;
GHashTableIter iter;
gpointer fid;
- int err;
int nclosed = 0;
/* prevent multiple coroutines running this function simultaniously */
@@ -507,13 +506,16 @@ void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu)
*/
v9fs_co_run_in_worker({
QSLIST_FOREACH(f, &reclaim_list, reclaim_next) {
- err = (f->fid_type == P9_FID_DIR) ?
+ /*
+ * 'man 2 close' suggests to ignore close() errors except of EBADF,
+ * not checking for EBADF here either as FIDs were picked above by
+ * having a valid file descriptor
+ */
+ (f->fid_type == P9_FID_DIR) ?
s->ops->closedir(&s->ctx, &f->fs_reclaim) :
s->ops->close(&s->ctx, &f->fs_reclaim);
- if (!err) {
- /* total_open_fd must only be mutated on main thread */
- nclosed++;
- }
+ /* total_open_fd must only be mutated on main thread */
+ nclosed++;
}
});
total_open_fd -= nclosed;
diff --git a/hw/9pfs/codir.c b/hw/9pfs/codir.c
index 2068a4779d..f1fd97c8a7 100644
--- a/hw/9pfs/codir.c
+++ b/hw/9pfs/codir.c
@@ -353,7 +353,8 @@ int coroutine_fn v9fs_co_closedir(V9fsPDU *pdu,
V9fsFidOpenState *fs)
err = -errno;
}
});
- if (!err) {
+ /* 'man 2 close' suggests to ignore close() errors except of EBADF */
+ if (!err || errno != EBADF) {
total_open_fd--;
}
return err;
diff --git a/hw/9pfs/cofile.c b/hw/9pfs/cofile.c
index 71174c3e4a..1e9f6da42a 100644
--- a/hw/9pfs/cofile.c
+++ b/hw/9pfs/cofile.c
@@ -197,7 +197,8 @@ int coroutine_fn v9fs_co_close(V9fsPDU *pdu,
V9fsFidOpenState *fs)
err = -errno;
}
});
- if (!err) {
+ /* 'man 2 close' suggests to ignore close() errors except of EBADF */
+ if (!err || errno != EBADF) {
total_open_fd--;
}
return err;
--
2.39.5
