DAOS-12751 tool: Add a daos filesystem evict command.

Add a command to tell dfuse and the kernel to evict a
path in dfuse.  This is implemented via a ioctl that
sets a flag on the file handle, when the file is then
closed the kernel is then told the dentry for the file
is no longer valid which should cause the kernel to
forget the entry and any contents if the entry is
a directory.

Required-githooks: true

Signed-off-by: Ashley Pittman <ashley.m.pittman@intel.com>

src/client/dfuse/dfuse.h

@@ -136,6 +136,8 @@ struct dfuse_obj_hdl {
 	bool                      doh_kreaddir_started;
 	/* Set to true if readdir calls reach EOF made on this handle */
 	bool                      doh_kreaddir_finished;
+
+	bool                      doh_evict_on_close;
 };
 
 /* Readdir support.

src/client/dfuse/ops/ioctl.c

@@ -336,6 +336,12 @@ void dfuse_cb_ioctl(fuse_req_t req, fuse_ino_t ino, unsigned int cmd, void *arg,
 
 	DFUSE_TRA_DEBUG(oh, "ioctl cmd=%#x", cmd);
 
+	if (cmd == DFUSE_IOCTL_DFUSE_EVICT) {
+		oh->doh_evict_on_close = true;
+		DFUSE_REPLY_IOCTL_SIZE(oh, req, NULL, 0);
+		return;
+	}
+
 	if (cmd == DFUSE_IOCTL_IL) {
 		if (out_bufsz < sizeof(struct dfuse_il_reply))
 			D_GOTO(out_err, rc = EIO);

src/client/dfuse/ops/open.c

@@ -12,7 +12,7 @@ dfuse_cb_open(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi)
 {
 	struct dfuse_projection_info *fs_handle = fuse_req_userdata(req);
 	struct dfuse_inode_entry     *ie;
-	d_list_t		     *rlink;
+	d_list_t                     *rlink;
 	struct dfuse_obj_hdl         *oh     = NULL;
 	struct fuse_file_info         fi_out = {0};
 	int                           rc;
@@ -99,9 +99,10 @@ dfuse_cb_open(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi)
 void
 dfuse_cb_release(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi)
 {
-	struct dfuse_obj_hdl *oh = (struct dfuse_obj_hdl *)fi->fh;
-	int                   rc;
-	uint32_t              il_calls;
+	struct dfuse_projection_info *fs_handle = fuse_req_userdata(req);
+	struct dfuse_obj_hdl         *oh        = (struct dfuse_obj_hdl *)fi->fh;
+	int                           rc;
+	uint32_t                      il_calls;
 
 	/* Perform the opposite of what the ioctl call does, always change the open handle count
 	 * but the inode only tracks number of open handles with non-zero ioctl counts
@@ -152,5 +153,15 @@ dfuse_cb_release(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi)
 		DFUSE_REPLY_ZERO(oh, req);
 	else
 		DFUSE_REPLY_ERR_RAW(oh, req, rc);
+
+	if (oh->doh_evict_on_close) {
+		rc = fuse_lowlevel_notify_inval_entry(fs_handle->dpi_info->di_session,
+						      oh->doh_ie->ie_parent, oh->doh_ie->ie_name,
+						      strnlen(oh->doh_ie->ie_name, NAME_MAX));
+
+		if (rc != 0)
+			DFUSE_TRA_ERROR(oh->doh_ie, "inval_entry() returned: %d (%s)", rc,
+					strerror(-rc));
+	}
 	D_FREE(oh);
 }

src/control/cmd/daos/filesystem.go

@@ -37,6 +37,7 @@ type fsCmd struct {
 	ResetAttr      fsResetAttrCmd      `command:"reset-attr" description:"reset fs attributes"`
 	ResetChunkSize fsResetChunkSizeCmd `command:"reset-chunk-size" description:"reset fs chunk size"`
 	ResetObjClass  fsResetOclassCmd    `command:"reset-oclass" description:"reset fs obj class"`
+	DfuseEvict     fsDfuseEvictCmd     `command:"evict" description:"Evict object from dfuse"`
 }
 
 type fsCopyCmd struct {
@@ -428,3 +429,27 @@ func (cmd *fsFixRootCmd) Execute(_ []string) error {
 
 	return nil
 }
+
+type fsDfuseEvictCmd struct {
+	daosCmd
+
+	Path string `long:"path" description:"Path to evict from dfuse" required:"1"`
+}
+
+func (cmd *fsDfuseEvictCmd) Execute(_ []string) error {
+	ap, deallocCmdArgs, err := allocCmdArgs(cmd.Logger)
+	if err != nil {
+		return err
+	}
+
+	ap.path = C.CString(cmd.Path)
+	defer freeString(ap.path)
+	defer deallocCmdArgs()
+
+	rc := C.dfuse_evict(ap)
+	if err := daosError(rc); err != nil {
+		return errors.Wrapf(err, "failed to evict %s", cmd.Path)
+	}
+
+	return nil
+}

src/include/dfuse_ioctl.h

@@ -15,9 +15,7 @@
 
 #define DFUSE_IOCTL_REPLY_CORE   (DFUSE_IOCTL_REPLY_BASE)
 
-/* (DFUSE_IOCTL_REPLY_BASE + 1) is reserved by an older version of
- * IOCTL_REPLY_SIZE
- */
+/* (DFUSE_IOCTL_REPLY_BASE + 1) is reserved by an older version of IOCTL_REPLY_SIZE */
 
 #define DFUSE_IOCTL_REPLY_POH    (DFUSE_IOCTL_REPLY_BASE + 2)
 #define DFUSE_IOCTL_REPLY_COH    (DFUSE_IOCTL_REPLY_BASE + 3)
@@ -26,8 +24,8 @@
 #define DFUSE_IOCTL_REPLY_SIZE   (DFUSE_IOCTL_REPLY_BASE + 6)
 #define DFUSE_IOCTL_REPLY_DSIZE  (DFUSE_IOCTL_REPLY_BASE + 7)
 #define DFUSE_IOCTL_REPLY_PFILE  (DFUSE_IOCTL_REPLY_BASE + 8)
-
 #define DFUSE_IOCTL_R_DFUSE_USER (DFUSE_IOCTL_REPLY_BASE + 9)
+#define DFUSE_IOCTL_EVICT_NR     (DFUSE_IOCTL_REPLY_BASE + 10)
 
 /** Metadada caching is enabled for this file */
 #define DFUSE_IOCTL_FLAGS_MCACHE (0x1)
@@ -76,4 +74,6 @@ struct dfuse_user_reply {
 #define DFUSE_IOCTL_DFUSE_USER                                                                     \
 	((int)_IOR(DFUSE_IOCTL_TYPE, DFUSE_IOCTL_R_DFUSE_USER, struct dfuse_user_reply))
 
+#define DFUSE_IOCTL_DFUSE_EVICT ((int)_IO(DFUSE_IOCTL_TYPE, DFUSE_IOCTL_EVICT_NR))
+
 #endif /* __DFUSE_IOCTL_H__ */

src/utils/daos_hdlr.c

@@ -22,6 +22,7 @@
 #include <sys/xattr.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/ioctl.h>
 #include <fcntl.h>
 #include <dlfcn.h>
 #include <daos.h>
@@ -40,6 +41,8 @@
 
 #include "daos_hdlr.h"
 
+#include "dfuse_ioctl.h"
+
 struct file_dfs {
 	enum {POSIX, DAOS} type;
 	int fd;
@@ -2423,3 +2426,35 @@ cont_clone_hdlr(struct cmd_args_s *ap)
 	}
 	return rc;
 }
+
+int
+dfuse_evict(struct cmd_args_s *ap)
+{
+	struct stat buf;
+	int         rc;
+	int         fd;
+
+	fd = open(ap->path, O_NOFOLLOW, O_RDONLY);
+	if (fd < 0) {
+		rc = errno;
+		DH_PERROR_SYS(ap, rc, "Failed to open path");
+		return daos_errno2der(rc);
+	}
+
+	rc = fstat(fd, &buf);
+	if (rc < 0) {
+		rc = errno;
+		DH_PERROR_SYS(ap, rc, "Failed to stat file");
+		return daos_errno2der(rc);
+	}
+
+	rc = ioctl(fd, DFUSE_IOCTL_DFUSE_EVICT);
+	if (rc < 0) {
+		rc = errno;
+		DH_PERROR_SYS(ap, rc, "ioctl failed");
+		return daos_errno2der(rc);
+	}
+
+	close(fd);
+	return -DER_SUCCESS;
+}

src/utils/daos_hdlr.h

@@ -199,6 +199,10 @@ int fs_relink_root_hdlr(struct cmd_args_s *ap);
 int cont_check_hdlr(struct cmd_args_s *ap);
 int cont_clone_hdlr(struct cmd_args_s *ap);
 
+/* Dfuse operations */
+int
+dfuse_evict(struct cmd_args_s *ap);
+
 /* TODO implement the following container op functions
  * all with signatures similar to this:
  * int cont_FN_hdlr(struct cmd_args_s *ap)

utils/node_local_test.py

@@ -2475,6 +2475,18 @@ def test_xattr(self):
             for (key, value) in xattr.get_all(fd):
                 print(f'xattr is {key}:{value}')
 
+    @needs_dfuse
+    def test_evict(self):
+        """Evict a file from dfuse"""
+        new_file = join(self.dfuse.dir, 'e_file')
+        with open(new_file, 'w'):
+            pass
+
+        rc = run_daos_cmd(self.conf, ['filesystem', 'evict', '--path', new_file])
+        print(rc)
+        assert rc.returncode == 0, rc
+        time.sleep(5)
+
     @needs_dfuse
     def test_list_xattr(self):
         """Perform tests with listing extended attributes.