Merge pull request #15645 from daos-stack/wangdi/google_26_dfuse

patches series for dfuse to support simultaneous reads

Author: jolivier23

docs/user/filesystem.md

@@ -228,7 +228,6 @@ Additionally, there are several optional command-line options:
 | --container=<label\|uuid\> | container label or uuid to open  |
 | --sys-name=<name\>         | DAOS system name                 |
 | --foreground               | run in foreground                |
-| --singlethreaded           | run single threaded              |
 | --thread-count=<count>     | Number of threads to use         |
 | --multi-user               | Run in multi user mode           |
 | --read-only                | Mount in read-only mode          |

src/client/dfuse/SConscript

@@ -7,6 +7,7 @@ DFUSE_SRC = ['dfuse_core.c',
              'dfuse_main.c',
              'dfuse_fuseops.c',
              'inval.c',
+             'file.c',
              'dfuse_cont.c',
              'dfuse_thread.c',
              'dfuse_pool.c']

src/client/dfuse/dfuse.h

@@ -29,7 +29,6 @@ struct dfuse_info {
 	char                *di_mountpoint;
 	int32_t              di_thread_count;
 	uint32_t             di_eq_count;
-	bool                 di_threaded;
 	bool                 di_foreground;
 	bool                 di_caching;
 	bool                 di_multi_user;
@@ -96,6 +95,9 @@ struct dfuse_eq {
  * memory consumption */
 #define DFUSE_MAX_PRE_READ (1024 * 1024 * 4)
 
+/* Maximum file-size for pre-read in all cases */
+#define DFUSE_MAX_PRE_READ_ONCE (1024 * 1024 * 1)
+
 /* Launch fuse, and do not return until complete */
 int
 dfuse_launch_fuse(struct dfuse_info *dfuse_info, struct fuse_args *args);
@@ -137,9 +139,10 @@ struct dfuse_inode_entry;
  * when EOF is returned to the kernel.  If it's still present on release then it's freed then.
  */
 struct dfuse_pre_read {
-	pthread_mutex_t     dra_lock;
+	d_list_t            req_list;
 	struct dfuse_event *dra_ev;
 	int                 dra_rc;
+	bool                complete;
 };
 
 /** what is returned as the handle for fuse fuse_file_info on create/open/opendir */
@@ -149,8 +152,6 @@ struct dfuse_obj_hdl {
 	/** the DFS object handle.  Not created for directories. */
 	dfs_obj_t                *doh_obj;
 
-	struct dfuse_pre_read    *doh_readahead;
-
 	/** the inode entry for the file */
 	struct dfuse_inode_entry *doh_ie;
 
@@ -169,17 +170,24 @@ struct dfuse_obj_hdl {
 	/* Pointer to the last returned drc entry */
 	struct dfuse_readdir_c   *doh_rd_nextc;
 
-	/* Linear read function, if a file is read from start to end then this normally requires
-	 * a final read request at the end of the file that returns zero bytes.  Detect this case
-	 * and when the final read is detected then just return without a round trip.
-	 * Store a flag for this being enabled (starts as true, but many I/O patterns will set it
-	 * to false), the expected position of the next read and a boolean for if EOF has been
-	 * detected.
+	/* Linear read tracking.  If a file is opened and read from start to finish then this is
+	 * called a linear read, linear reads however may or may not read EOF at the end of a file,
+	 * as the reader may be checking the file size.
+	 *
+	 * Detect this case and track it at the file handle level, this is then used in two places:
+	 *  For read of EOF it means the round-trip can be avoided.
+	 *  On release we can use this flag to apply a setting to the directory inode.
+	 *
+	 * This flag starts enabled and many I/O patterns will disable it.  We also store the next
+	 * expected read position and if EOF has been reached.
 	 */
+
 	off_t                     doh_linear_read_pos;
 	bool                      doh_linear_read;
 	bool                      doh_linear_read_eof;
 
+	bool                      doh_set_linear_read;
+
 	/** True if caching is enabled for this file. */
 	bool                      doh_caching;
 
@@ -197,6 +205,8 @@ struct dfuse_obj_hdl {
 	bool                      doh_kreaddir_finished;
 
 	bool                      doh_evict_on_close;
+	/* the handle is doing readhead for the moment */
+	bool                      doh_readahead_inflight;
 };
 
 /* Readdir support.
@@ -401,11 +411,20 @@ struct dfuse_event {
 	d_iov_t          de_iov;
 	d_sg_list_t      de_sgl;
 	d_list_t         de_list;
+
+	/* Position in a list of events, this will either be off active->open_reads or
+	 * de->de_read_slaves.
+	 */
+	d_list_t         de_read_list;
+	/* List of slave events */
+	d_list_t         de_read_slaves;
 	struct dfuse_eq *de_eqt;
 	union {
 		struct dfuse_obj_hdl     *de_oh;
 		struct dfuse_inode_entry *de_ie;
+		struct read_chunk_data   *de_cd;
 	};
+	struct dfuse_info *de_di;
 	off_t  de_req_position; /**< The file position requested by fuse */
 	union {
 		size_t de_req_len;
@@ -1009,10 +1028,32 @@ struct dfuse_inode_entry {
 	 */
 	ATOMIC bool               ie_linear_read;
 
+	struct active_inode      *ie_active;
+
 	/* Entry on the evict list */
 	d_list_t                  ie_evict_entry;
 };
 
+struct active_inode {
+	d_list_t               chunks;
+	d_list_t               open_reads;
+	pthread_spinlock_t     lock;
+	ATOMIC uint64_t        read_count;
+	struct dfuse_pre_read *readahead;
+};
+
+/* Increase active count on inode.  This takes a reference and allocates ie->active as required */
+int
+active_ie_init(struct dfuse_inode_entry *ie);
+
+/* Mark a oh as closing and drop the ref on inode active */
+void
+active_oh_decref(struct dfuse_info *dfuse_info, struct dfuse_obj_hdl *oh);
+
+/* Decrease active count on inode, called on error where there is no oh */
+void
+active_ie_decref(struct dfuse_info *dfuse_info, struct dfuse_inode_entry *ie);
+
 /* Flush write-back cache writes to a inode.  It does this by waiting for and then releasing an
  * exclusive lock on the inode.  Writes take a shared lock so this will block until all pending
  * writes are complete.
@@ -1108,6 +1149,13 @@ dfuse_compute_inode(struct dfuse_cont *dfs,
 void
 dfuse_cache_evict_dir(struct dfuse_info *dfuse_info, struct dfuse_inode_entry *ie);
 
+/* Free any read chunk data for an inode.
+ *
+ * Returns true if feature was used.
+ */
+bool
+read_chunk_close(struct dfuse_inode_entry *ie);
+
 /* Metadata caching functions. */
 
 /* Mark the cache as up-to-date from now */
@@ -1171,7 +1219,15 @@ bool
 dfuse_dcache_get_valid(struct dfuse_inode_entry *ie, double max_age);
 
 void
-dfuse_pre_read(struct dfuse_info *dfuse_info, struct dfuse_obj_hdl *oh);
+dfuse_pre_read(struct dfuse_info *dfuse_info, struct dfuse_obj_hdl *oh, struct dfuse_event *ev);
+
+int
+dfuse_pre_read_init(struct dfuse_info *dfuse_info, struct dfuse_inode_entry *ie,
+		    struct dfuse_event **evp);
+
+void
+dfuse_pre_read_abort(struct dfuse_info *dfuse_info, struct dfuse_obj_hdl *oh,
+		     struct dfuse_event *ev, int rc);
 
 int
 check_for_uns_ep(struct dfuse_info *dfuse_info, struct dfuse_inode_entry *ie, char *attr,

src/client/dfuse/dfuse_core.c

@@ -1274,6 +1274,7 @@ dfuse_ie_close(struct dfuse_info *dfuse_info, struct dfuse_inode_entry *ie)
 		  atomic_load_relaxed(&ie->ie_il_count));
 	D_ASSERTF(atomic_load_relaxed(&ie->ie_open_count) == 0, "open_count is %d",
 		  atomic_load_relaxed(&ie->ie_open_count));
+	D_ASSERT(!ie->ie_active);
 
 	if (ie->ie_obj) {
 		rc = dfs_release(ie->ie_obj);
@@ -1317,6 +1318,8 @@ dfuse_read_event_size(void *arg, size_t size)
 		ev->de_sgl.sg_nr       = 1;
 	}
 
+	D_INIT_LIST_HEAD(&ev->de_read_slaves);
+
 	rc = daos_event_init(&ev->de_ev, ev->de_eqt->de_eq, NULL);
 	if (rc != -DER_SUCCESS) {
 		return false;

src/client/dfuse/dfuse_fuseops.c

@@ -1,5 +1,5 @@
 /**
- * (C) Copyright 2016-2023 Intel Corporation.
+ * (C) Copyright 2016-2024 Intel Corporation.
  *
  * SPDX-License-Identifier: BSD-2-Clause-Patent
  */
@@ -88,7 +88,12 @@ dfuse_fuse_init(void *arg, struct fuse_conn_info *conn)
 	DFUSE_TRA_INFO(dfuse_info, "kernel readdir cache support compiled in");
 
 	conn->want |= FUSE_CAP_READDIRPLUS;
-	conn->want |= FUSE_CAP_READDIRPLUS_AUTO;
+	/* Temporarily force readdir plus for all cases now, which can
+	 * help to save some lookup RPC for some cases. Though this can be
+	 * removed once we use object enumeration to replace the normal key
+	 * enumeration for readdir. XXX
+	 */
+	conn->want &= ~FUSE_CAP_READDIRPLUS_AUTO;
 
 #ifdef FUSE_CAP_CACHE_SYMLINKS
 	conn->want |= FUSE_CAP_CACHE_SYMLINKS;

src/client/dfuse/dfuse_main.c

@@ -166,6 +166,7 @@ dfuse_bg(struct dfuse_info *dfuse_info)
  *
  * Should be called from the post_start plugin callback and creates
  * a filesystem.
+ * Returns a DAOS error code.
  * Returns true on success, false on failure.
  */
 int
@@ -204,18 +205,17 @@ dfuse_launch_fuse(struct dfuse_info *dfuse_info, struct fuse_args *args)
 		DFUSE_TRA_ERROR(dfuse_info, "Error sending signal to fg: "DF_RC, DP_RC(rc));
 
 	/* Blocking */
-	if (dfuse_info->di_threaded)
-		rc = dfuse_loop(dfuse_info);
-	else
-		rc = fuse_session_loop(dfuse_info->di_session);
-	if (rc != 0)
+	rc = dfuse_loop(dfuse_info);
+	if (rc != 0) {
 		DHS_ERROR(dfuse_info, rc, "Fuse loop exited");
+		rc = daos_errno2der(rc);
+	}
 
 umount:
 
 	fuse_session_unmount(dfuse_info->di_session);
 
-	return daos_errno2der(rc);
+	return rc;
 }
 
 #define DF_POOL_PREFIX "pool="
@@ -279,7 +279,6 @@ show_help(char *name)
 	    "	   --path=<path>	Path to load UNS pool/container data\n"
 	    "	   --sys-name=STR	DAOS system name context for servers\n"
 	    "\n"
-	    "	-S --singlethread	Single threaded (deprecated)\n"
 	    "	-t --thread-count=count	Total number of threads to use\n"
 	    "	-e --eq-count=count	Number of event queues to use\n"
 	    "	-f --foreground		Run in foreground\n"
@@ -423,7 +422,6 @@ main(int argc, char **argv)
 					     {"pool", required_argument, 0, 'p'},
 					     {"container", required_argument, 0, 'c'},
 					     {"sys-name", required_argument, 0, 'G'},
-					     {"singlethread", no_argument, 0, 'S'},
 					     {"thread-count", required_argument, 0, 't'},
 					     {"eq-count", required_argument, 0, 'e'},
 					     {"foreground", no_argument, 0, 'f'},
@@ -447,13 +445,12 @@ main(int argc, char **argv)
 	if (dfuse_info == NULL)
 		D_GOTO(out_debug, rc = -DER_NOMEM);
 
-	dfuse_info->di_threaded = true;
 	dfuse_info->di_caching  = true;
 	dfuse_info->di_wb_cache = true;
 	dfuse_info->di_eq_count = 1;
 
 	while (1) {
-		c = getopt_long(argc, argv, "Mm:St:o:fhe:v", long_options, NULL);
+		c = getopt_long(argc, argv, "Mm:t:o:fhe:v", long_options, NULL);
 
 		if (c == -1)
 			break;
@@ -491,13 +488,6 @@ main(int argc, char **argv)
 		case 'P':
 			path = optarg;
 			break;
-		case 'S':
-			/* Set it to be single threaded, but allow an extra one
-			 * for the event queue processing
-			 */
-			dfuse_info->di_threaded     = false;
-			dfuse_info->di_thread_count = 2;
-			break;
 		case 'e':
 			dfuse_info->di_eq_count = atoi(optarg);
 			break;
@@ -564,7 +554,7 @@ main(int argc, char **argv)
 	 * check CPU binding.  If bound to a number of cores then launch that number of threads,
 	 * if not bound them limit to 16.
 	 */
-	if (dfuse_info->di_threaded && !have_thread_count) {
+	if (!have_thread_count) {
 		struct hwloc_topology *hwt;
 		hwloc_const_cpuset_t   hw;
 		int                    total;