[Qemu-devel] [PATCH v2 1/2] block/nfs: Introduce runtime_opts in NFS

[Ashijeet Acharya <ashijeetacharya@gmail.com>]

Make NFS block driver use various fine grained runtime_opts.
Set .bdrv_parse_filename() to nfs_parse_filename() and introduce two
new functions nfs_parse_filename() and nfs_parse_uri() to help parsing
the URI.

Signed-off-by: Ashijeet Acharya <ashijeetacharya@gmail.com>
---
 block/nfs.c | 348 +++++++++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 253 insertions(+), 95 deletions(-)

diff --git a/block/nfs.c b/block/nfs.c
index 8602a44..666ccf2 100644
--- a/block/nfs.c
+++ b/block/nfs.c
@@ -35,8 +35,12 @@
 #include "qemu/uri.h"
 #include "qemu/cutils.h"
 #include "sysemu/sysemu.h"
+#include "qapi/qmp/qdict.h"
+#include "qapi/qmp/qint.h"
+#include "qapi/qmp/qstring.h"
 #include <nfsc/libnfs.h>
 
+
 #define QEMU_NFS_MAX_READAHEAD_SIZE 1048576
 #define QEMU_NFS_MAX_PAGECACHE_SIZE (8388608 / NFS_BLKSIZE)
 #define QEMU_NFS_MAX_DEBUG_LEVEL 2
@@ -61,6 +65,118 @@ typedef struct NFSRPC {
     NFSClient *client;
 } NFSRPC;
 
+static int nfs_parse_uri(const char *filename, QDict *options, Error **errp)
+{
+    URI *uri = NULL;
+    QueryParams *qp = NULL;
+    int ret = 0, i;
+
+    uri = uri_parse(filename);
+    if (!uri) {
+        error_setg(errp, "Invalid URI specified");
+        ret = -EINVAL;
+        goto out;
+    }
+    if (strcmp(uri->scheme, "nfs") != 0) {
+        error_setg(errp, "URI scheme must be 'nfs'");
+        ret = -EINVAL;
+        goto out;
+    }
+
+    if (!uri->server) {
+        error_setg(errp, "missing hostname in URI");
+        ret = -EINVAL;
+        goto out;
+    }
+
+    if (!uri->path) {
+        error_setg(errp, "missing file path in URI");
+        ret = -EINVAL;
+        goto out;
+    }
+
+    qp = query_params_parse(uri->query);
+    if (!qp) {
+        error_setg(errp, "could not parse query parameters");
+        ret = -EINVAL;
+        goto out;
+    }
+
+    qdict_put(options, "host", qstring_from_str(uri->server));
+
+    qdict_put(options, "path", qstring_from_str(uri->path));
+
+    for (i = 0; i < qp->n; i++) {
+        if (!qp->p[i].value) {
+            error_setg(errp, "Value for NFS parameter expected: %s",
+                       qp->p[i].name);
+            goto out;
+        }
+        if (parse_uint_full(qp->p[i].value, NULL, 0)) {
+            error_setg(errp, "Illegal value for NFS parameter: %s",
+                       qp->p[i].name);
+            goto out;
+        }
+        if (!strcmp(qp->p[i].name, "uid")) {
+            qdict_put(options, "uid",
+                      qstring_from_str(qp->p[i].value));
+        } else if (!strcmp(qp->p[i].name, "gid")) {
+            qdict_put(options, "gid",
+                      qstring_from_str(qp->p[i].value));
+        } else if (!strcmp(qp->p[i].name, "tcp-syncnt")) {
+            qdict_put(options, "tcp-syncnt",
+                      qstring_from_str(qp->p[i].value));
+        } else if (!strcmp(qp->p[i].name, "readahead")) {
+            qdict_put(options, "readahead",
+                      qstring_from_str(qp->p[i].value));
+        } else if (!strcmp(qp->p[i].name, "pagecache")) {
+            qdict_put(options, "pagecache",
+                      qstring_from_str(qp->p[i].value));
+        } else if (!strcmp(qp->p[i].name, "debug")) {
+            qdict_put(options, "debug",
+                      qstring_from_str(qp->p[i].value));
+        } else {
+            error_setg(errp, "Unknown NFS parameter name: %s",
+                       qp->p[i].name);
+            goto out;
+        }
+    }
+out:
+    if (qp) {
+        query_params_free(qp);
+    }
+    if (uri) {
+        uri_free(uri);
+    }
+    return ret;
+}
+
+static void nfs_parse_filename(const char *filename, QDict *options,
+                               Error **errp)
+{
+    int ret = 0;
+
+    if (qdict_haskey(options, "host") ||
+        qdict_haskey(options, "path") ||
+        qdict_haskey(options, "uid") ||
+        qdict_haskey(options, "gid") ||
+        qdict_haskey(options, "tcp-syncnt") ||
+        qdict_haskey(options, "readahead") ||
+        qdict_haskey(options, "pagecache") ||
+        qdict_haskey(options, "debug")) {
+        error_setg(errp, "host/path/uid/gid/tcp-syncnt/readahead/pagecache"
+                         "/debug and a filename may not be used at the same"
+                         " time");
+        return;
+    }
+
+    ret = nfs_parse_uri(filename, options, errp);
+    if (ret < 0) {
+        error_setg(errp, "No valid URL specified");
+    }
+    return;
+}
+
 static void nfs_process_read(void *arg);
 static void nfs_process_write(void *arg);
 
@@ -228,15 +344,49 @@ static int coroutine_fn nfs_co_flush(BlockDriverState *bs)
     return task.ret;
 }
 
-/* TODO Convert to fine grained options */
 static QemuOptsList runtime_opts = {
     .name = "nfs",
     .head = QTAILQ_HEAD_INITIALIZER(runtime_opts.head),
     .desc = {
         {
-            .name = "filename",
+            .name = "host",
+            .type = QEMU_OPT_STRING,
+            .help = "Host to connect to",
+        },
+        {
+            .name = "path",
             .type = QEMU_OPT_STRING,
-            .help = "URL to the NFS file",
+            .help = "Path of the image on the host",
+        },
+        {
+            .name = "uid",
+            .type = QEMU_OPT_NUMBER,
+            .help = "UID value to use when talking to the server",
+        },
+        {
+            .name = "gid",
+            .type = QEMU_OPT_NUMBER,
+            .help = "GID value to use when talking to the server",
+        },
+        {
+            .name = "tcp-syncnt",
+            .type = QEMU_OPT_NUMBER,
+            .help = "Number of SYNs to send during the session establish",
+        },
+        {
+            .name = "readahead",
+            .type = QEMU_OPT_NUMBER,
+            .help = "Set the readahead size in bytes",
+        },
+        {
+            .name = "pagecache",
+            .type = QEMU_OPT_NUMBER,
+            .help = "Set the pagecache size in bytes",
+        },
+        {
+            .name = "debug",
+            .type = QEMU_OPT_NUMBER,
+            .help = "Set the NFS debug level (max 2)",
         },
         { /* end of list */ }
     },
@@ -279,25 +429,40 @@ static void nfs_file_close(BlockDriverState *bs)
     nfs_client_close(client);
 }
 
-static int64_t nfs_client_open(NFSClient *client, const char *filename,
+static int64_t nfs_client_open(NFSClient *client, QDict *options,
                                int flags, Error **errp, int open_flags)
 {
-    int ret = -EINVAL, i;
+    int ret = -EINVAL;
+    QemuOpts *opts = NULL;
+    Error *local_err = NULL;
     struct stat st;
-    URI *uri;
-    QueryParams *qp = NULL;
     char *file = NULL, *strp = NULL;
+    const char *host, *path;
+    unsigned long long val;
 
-    uri = uri_parse(filename);
-    if (!uri) {
-        error_setg(errp, "Invalid URL specified");
-        goto fail;
+    opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
+    qemu_opts_absorb_qdict(opts, options, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        ret = -EINVAL;
+        goto out;
     }
-    if (!uri->server) {
-        error_setg(errp, "Invalid URL specified");
-        goto fail;
+
+    host = qemu_opt_get(opts, "host");
+    if (!host) {
+        ret = -EINVAL;
+        error_setg(errp, "No hostname was specified");
+        goto out;
     }
-    strp = strrchr(uri->path, '/');
+
+    path = qemu_opt_get(opts, "path");
+    if (!path) {
+        ret = -EINVAL;
+        error_setg(errp, "No path was specified");
+        goto out;
+    }
+
+    strp = strrchr(path, '/');
     if (strp == NULL) {
         error_setg(errp, "Invalid URL specified");
         goto fail;
@@ -311,79 +476,77 @@ static int64_t nfs_client_open(NFSClient *client, const char *filename,
         goto fail;
     }
 
-    qp = query_params_parse(uri->query);
-    for (i = 0; i < qp->n; i++) {
-        unsigned long long val;
-        if (!qp->p[i].value) {
-            error_setg(errp, "Value for NFS parameter expected: %s",
-                       qp->p[i].name);
+    if (qemu_opt_get(opts, "uid")) {
+        nfs_set_uid(client->context,
+                    qemu_opt_get_number(opts, "uid", getuid()));
+    }
+
+    if (qemu_opt_get(opts, "gid")) {
+        nfs_set_gid(client->context,
+                    qemu_opt_get_number(opts, "gid", getgid()));
+    }
+
+    if (qemu_opt_get(opts, "tcp-syncnt")) {
+        nfs_set_tcp_syncnt(client->context,
+                           qemu_opt_get_number(opts, "tcp-syncnt", 0));
+    }
+
+#ifdef LIBNFS_FEATURE_READAHEAD
+    if (qemu_opt_get(opts, "readahead")) {
+        if (open_flags & BDRV_O_NOCACHE) {
+            error_setg(errp, "Cannot enable NFS readahead "
+                             "if cache.direct = on");
             goto fail;
         }
-        if (parse_uint_full(qp->p[i].value, &val, 0)) {
-            error_setg(errp, "Illegal value for NFS parameter: %s",
-                       qp->p[i].name);
-            goto fail;
+        val = qemu_opt_get_number(opts, "readahead", 0);
+        if (val > QEMU_NFS_MAX_READAHEAD_SIZE) {
+            error_report("NFS Warning: Truncating NFS readahead "
+                         "size to %d", QEMU_NFS_MAX_READAHEAD_SIZE);
+            val = QEMU_NFS_MAX_READAHEAD_SIZE;
         }
-        if (!strcmp(qp->p[i].name, "uid")) {
-            nfs_set_uid(client->context, val);
-        } else if (!strcmp(qp->p[i].name, "gid")) {
-            nfs_set_gid(client->context, val);
-        } else if (!strcmp(qp->p[i].name, "tcp-syncnt")) {
-            nfs_set_tcp_syncnt(client->context, val);
-#ifdef LIBNFS_FEATURE_READAHEAD
-        } else if (!strcmp(qp->p[i].name, "readahead")) {
-            if (open_flags & BDRV_O_NOCACHE) {
-                error_setg(errp, "Cannot enable NFS readahead "
-                                 "if cache.direct = on");
-                goto fail;
-            }
-            if (val > QEMU_NFS_MAX_READAHEAD_SIZE) {
-                error_report("NFS Warning: Truncating NFS readahead"
-                             " size to %d", QEMU_NFS_MAX_READAHEAD_SIZE);
-                val = QEMU_NFS_MAX_READAHEAD_SIZE;
-            }
-            nfs_set_readahead(client->context, val);
+        nfs_set_readahead(client->context, val);
 #ifdef LIBNFS_FEATURE_PAGECACHE
-            nfs_set_pagecache_ttl(client->context, 0);
+        nfs_set_pagecache_ttl(client->context, 0);
 #endif
-            client->cache_used = true;
+        client->cache_used = true;
+    }
 #endif
+
 #ifdef LIBNFS_FEATURE_PAGECACHE
-            nfs_set_pagecache_ttl(client->context, 0);
-        } else if (!strcmp(qp->p[i].name, "pagecache")) {
-            if (open_flags & BDRV_O_NOCACHE) {
-                error_setg(errp, "Cannot enable NFS pagecache "
-                                 "if cache.direct = on");
-                goto fail;
-            }
-            if (val > QEMU_NFS_MAX_PAGECACHE_SIZE) {
-                error_report("NFS Warning: Truncating NFS pagecache"
-                             " size to %d pages", QEMU_NFS_MAX_PAGECACHE_SIZE);
-                val = QEMU_NFS_MAX_PAGECACHE_SIZE;
-            }
-            nfs_set_pagecache(client->context, val);
-            nfs_set_pagecache_ttl(client->context, 0);
-            client->cache_used = true;
+    nfs_set_pagecache_ttl(client->context, 0);
+    if (qemu_opt_get(opts, "pagecache")) {
+        if (open_flags & BDRV_O_NOCACHE) {
+            error_setg(errp, "Cannot enable NFS pagecache "
+                             "if cache.direct = on");
+            goto fail;
+        }
+        val = qemu_opt_get_number(opts, "pagecache", 0);
+        if (val > QEMU_NFS_MAX_PAGECACHE_SIZE) {
+            error_report("NFS Warning: Truncating NFS pagecache "
+                         "size to %d pages", QEMU_NFS_MAX_PAGECACHE_SIZE);
+            val = QEMU_NFS_MAX_PAGECACHE_SIZE;
+        }
+        nfs_set_pagecache(client->context, val);
+        nfs_set_pagecache_ttl(client->context, 0);
+        client->cache_used = true;
+    }
 #endif
+
 #ifdef LIBNFS_FEATURE_DEBUG
-        } else if (!strcmp(qp->p[i].name, "debug")) {
-            /* limit the maximum debug level to avoid potential flooding
-             * of our log files. */
-            if (val > QEMU_NFS_MAX_DEBUG_LEVEL) {
-                error_report("NFS Warning: Limiting NFS debug level"
-                             " to %d", QEMU_NFS_MAX_DEBUG_LEVEL);
-                val = QEMU_NFS_MAX_DEBUG_LEVEL;
-            }
-            nfs_set_debug(client->context, val);
-#endif
-        } else {
-            error_setg(errp, "Unknown NFS parameter name: %s",
-                       qp->p[i].name);
-            goto fail;
+    if (qemu_opt_get(opts, "debug")) {
+        val = qemu_opt_get_number(opts, "debug", 0);
+        /* limit the maximum debug level to avoid potential flooding
+         * of our log files. */
+        if (val > QEMU_NFS_MAX_DEBUG_LEVEL) {
+            error_report("NFS Warning: Limiting NFS debug level "
+                         "to %d", QEMU_NFS_MAX_DEBUG_LEVEL);
+            val = QEMU_NFS_MAX_DEBUG_LEVEL;
         }
+        nfs_set_debug(client->context, val);
     }
+#endif
 
-    ret = nfs_mount(client->context, uri->server, uri->path);
+    ret = nfs_mount(client->context, host, path);
     if (ret < 0) {
         error_setg(errp, "Failed to mount nfs share: %s",
                    nfs_get_error(client->context));
@@ -417,13 +580,11 @@ static int64_t nfs_client_open(NFSClient *client, const char *filename,
     client->st_blocks = st.st_blocks;
     client->has_zero_init = S_ISREG(st.st_mode);
     goto out;
+
 fail:
     nfs_client_close(client);
 out:
-    if (qp) {
-        query_params_free(qp);
-    }
-    uri_free(uri);
+    qemu_opts_del(opts);
     g_free(file);
     return ret;
 }
@@ -432,28 +593,17 @@ static int nfs_file_open(BlockDriverState *bs, QDict *options, int flags,
                          Error **errp) {
     NFSClient *client = bs->opaque;
     int64_t ret;
-    QemuOpts *opts;
-    Error *local_err = NULL;
 
     client->aio_context = bdrv_get_aio_context(bs);
 
-    opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
-    qemu_opts_absorb_qdict(opts, options, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
-        ret = -EINVAL;
-        goto out;
-    }
-    ret = nfs_client_open(client, qemu_opt_get(opts, "filename"),
+    ret = nfs_client_open(client, options,
                           (flags & BDRV_O_RDWR) ? O_RDWR : O_RDONLY,
                           errp, bs->open_flags);
     if (ret < 0) {
-        goto out;
+        return ret;
     }
     bs->total_sectors = ret;
     ret = 0;
-out:
-    qemu_opts_del(opts);
     return ret;
 }
 
@@ -475,6 +625,7 @@ static int nfs_file_create(const char *url, QemuOpts *opts, Error **errp)
     int ret = 0;
     int64_t total_size = 0;
     NFSClient *client = g_new0(NFSClient, 1);
+    QDict *options = NULL;
 
     client->aio_context = qemu_get_aio_context();
 
@@ -482,7 +633,14 @@ static int nfs_file_create(const char *url, QemuOpts *opts, Error **errp)
     total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
                           BDRV_SECTOR_SIZE);
 
-    ret = nfs_client_open(client, url, O_CREAT, errp, 0);
+    options = qdict_new();
+    ret = nfs_parse_uri(url, options, errp);
+    if (ret < 0) {
+        error_setg(errp, "No valid URL specified");
+        goto out;
+    }
+
+    ret = nfs_client_open(client, options, O_CREAT, errp, 0);
     if (ret < 0) {
         goto out;
     }
@@ -578,7 +736,7 @@ static BlockDriver bdrv_nfs = {
     .protocol_name                  = "nfs",
 
     .instance_size                  = sizeof(NFSClient),
-    .bdrv_needs_filename            = true,
+    .bdrv_parse_filename            = nfs_parse_filename,
     .create_opts                    = &nfs_create_opts,
 
     .bdrv_has_zero_init             = nfs_has_zero_init,
-- 
2.6.2