9pfs: Introduce futimens file op

Add an futimens operation to the fs driver and use if when a fid has
a valid file descriptor. This is required to support more cases where
the client wants to do an action on an unlinked file which it still
has an open file decriptor for.

Only 9P2000.L was considered.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <20250312152933.383967-5-groug@kaod.org>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>

diff --git a/fsdev/file-op-9p.h b/fsdev/file-op-9p.h
index 26ba1438c0edcf9c53f217a44ba1b395ab5fbf15..b9dae8c84c2309d5f78a417d1cdd915352e2db21 100644 (file)
--- a/fsdev/file-op-9p.h
+++ b/fsdev/file-op-9p.h
@@ -129,6 +129,8 @@ struct FileOperations {
     int (*chown)(FsContext *, V9fsPath *, FsCred *);
     int (*mknod)(FsContext *, V9fsPath *, const char *, FsCred *);
     int (*utimensat)(FsContext *, V9fsPath *, const struct timespec *);
+    int (*futimens)(FsContext *ctx, int fid_type, V9fsFidOpenState *fs,
+                    const struct timespec *times);
     int (*remove)(FsContext *, const char *);
     int (*symlink)(FsContext *, const char *, V9fsPath *,
                    const char *, FsCred *);

diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index 0b33da8d2a46a8255a2f83b8bbcba22413a2e6bc..31e216227cb9730118d1a065c9ae53137eb46bb1 100644 (file)
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -1100,6 +1100,14 @@ out:
     return ret;
 }
 
+static int local_futimens(FsContext *s, int fid_type, V9fsFidOpenState *fs,
+                          const struct timespec *times)
+{
+    int fd = local_fid_fd(fid_type, fs);
+
+    return qemu_futimens(fd, times);
+}
+
 static int local_unlinkat_common(FsContext *ctx, int dirfd, const char *name,
                                  int flags)
 {
@@ -1626,4 +1634,5 @@ FileOperations local_ops = {
     .unlinkat = local_unlinkat,
     .has_valid_file_handle = local_has_valid_file_handle,
     .ftruncate = local_ftruncate,
+    .futimens = local_futimens,
 };

diff --git a/hw/9pfs/9p-synth.c b/hw/9pfs/9p-synth.c
index 3d28afc4d03d9bea5d41029731de83de11742787..9cd18842242181776512ff9b2c07c850dd7e40ac 100644 (file)
--- a/hw/9pfs/9p-synth.c
+++ b/hw/9pfs/9p-synth.c
@@ -424,6 +424,13 @@ static int synth_utimensat(FsContext *fs_ctx, V9fsPath *path,
     return 0;
 }
 
+static int synth_futimens(FsContext *fs_ctx, int fid_type, V9fsFidOpenState *fs,
+                          const struct timespec *buf)
+{
+    errno = ENOSYS;
+    return -1;
+}
+
 static int synth_remove(FsContext *ctx, const char *path)
 {
     errno = EPERM;
@@ -664,4 +671,5 @@ FileOperations synth_ops = {
     .unlinkat     = synth_unlinkat,
     .has_valid_file_handle = synth_has_valid_file_handle,
     .ftruncate    = synth_ftruncate,
+    .futimens     = synth_futimens,
 };

diff --git a/hw/9pfs/9p-util.h b/hw/9pfs/9p-util.h
index 7bc4ec8e85cc16539db0817876057ea88be26933..a1924fe3f05a8f95c1965a60176039521ef8ef05 100644 (file)
--- a/hw/9pfs/9p-util.h
+++ b/hw/9pfs/9p-util.h
@@ -103,6 +103,7 @@ static inline int errno_to_dotl(int err) {
 #define qemu_renameat   renameat
 #define qemu_utimensat  utimensat
 #define qemu_unlinkat   unlinkat
+#define qemu_futimens   futimens
 
 static inline void close_preserve_errno(int fd)
 {

diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index c96f2d2d3d860bf372b330f432a6a7166683eadd..b22df3aa2b741dd98d31f66944cce7d1b91d130f 100644 (file)
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -1727,7 +1727,11 @@ static void coroutine_fn v9fs_setattr(void *opaque)
         } else {
             times[1].tv_nsec = UTIME_OMIT;
         }
-        err = v9fs_co_utimensat(pdu, &fidp->path, times);
+        if (fid_has_valid_file_handle(pdu->s, fidp)) {
+            err = v9fs_co_futimens(pdu, fidp, times);
+        } else {
+            err = v9fs_co_utimensat(pdu, &fidp->path, times);
+        }
         if (err < 0) {
             goto out;
         }

diff --git a/hw/9pfs/cofs.c b/hw/9pfs/cofs.c
index 893466fb1a4424eb56397a0a1fb7543b33431cf8..12fa8c9fe9cd0ae60c886f2061ca997e1e52b472 100644 (file)
--- a/hw/9pfs/cofs.c
+++ b/hw/9pfs/cofs.c
@@ -139,6 +139,25 @@ int coroutine_fn v9fs_co_utimensat(V9fsPDU *pdu, V9fsPath *path,
     return err;
 }
 
+int coroutine_fn v9fs_co_futimens(V9fsPDU *pdu, V9fsFidState *fidp,
+                                  struct timespec times[2])
+{
+    int err;
+    V9fsState *s = pdu->s;
+
+    if (v9fs_request_cancelled(pdu)) {
+        return -EINTR;
+    }
+    v9fs_co_run_in_worker(
+        {
+            err = s->ops->futimens(&s->ctx, fidp->fid_type, &fidp->fs, times);
+            if (err < 0) {
+                err = -errno;
+            }
+        });
+    return err;
+}
+
 int coroutine_fn v9fs_co_chown(V9fsPDU *pdu, V9fsPath *path, uid_t uid,
                                gid_t gid)
 {

diff --git a/hw/9pfs/coth.h b/hw/9pfs/coth.h
index 62e922dc12e33288f20bd698a48d16c57a98ee23..7906fa7782d89dde0bc14abc4b3b9203db68515a 100644 (file)
--- a/hw/9pfs/coth.h
+++ b/hw/9pfs/coth.h
@@ -71,6 +71,8 @@ int coroutine_fn v9fs_co_statfs(V9fsPDU *, V9fsPath *, struct statfs *);
 int coroutine_fn v9fs_co_lstat(V9fsPDU *, V9fsPath *, struct stat *);
 int coroutine_fn v9fs_co_chmod(V9fsPDU *, V9fsPath *, mode_t);
 int coroutine_fn v9fs_co_utimensat(V9fsPDU *, V9fsPath *, struct timespec [2]);
+int coroutine_fn v9fs_co_futimens(V9fsPDU *pdu, V9fsFidState *fidp,
+                                  struct timespec times[2]);
 int coroutine_fn v9fs_co_chown(V9fsPDU *, V9fsPath *, uid_t, gid_t);
 int coroutine_fn v9fs_co_truncate(V9fsPDU *, V9fsPath *, off_t);
 int coroutine_fn v9fs_co_ftruncate(V9fsPDU *pdu, V9fsFidState *fidp,