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Re: [Qemu-devel] [PATCH 1/2] block/nfs: Introduce runtime_opts in NFS
|
From: |
Ashijeet Acharya |
|
Subject: |
Re: [Qemu-devel] [PATCH 1/2] block/nfs: Introduce runtime_opts in NFS |
|
Date: |
Tue, 25 Oct 2016 00:12:26 +0530 |
On Mon, Oct 24, 2016 at 8:40 PM, Kevin Wolf <address@hidden> wrote:
> Am 19.10.2016 um 14:38 hat Ashijeet Acharya geschrieben:
>> 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. This will help us to prepare the NFS for blockdev-add.
>>
>> Signed-off-by: Ashijeet Acharya <address@hidden>
>> ---
>> block/nfs.c | 360
>> +++++++++++++++++++++++++++++++++++++++++++-----------------
>> 1 file changed, 261 insertions(+), 99 deletions(-)
>>
>> diff --git a/block/nfs.c b/block/nfs.c
>> index 8602a44..5eb909e 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 +65,127 @@ 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;
>> + const char *p;
>> +
>> + 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 || strcmp(uri->server, "") == 0) {
>
> No need to use strcmp(), !*uri->server is enough.
Yes, fixed the same for uri->path too.
>
>> + error_setg(errp, "missing hostname in URI");
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> +
>> + if (!uri->path || strcmp(uri->path, "") == 0) {
>> + error_setg(errp, "missing file path in URI");
>> + ret = -EINVAL;
>> + goto out;
>> + }
>> +
>> + p = uri->path ? uri->path : "/";
>
> You just checked that uri->path is non-NULL, so this is dead code.
>
>> + p += strspn(p, "/");
>> + if (p[0]) {
>> + qdict_put(options, "export", qstring_from_str(p));
>> + }
>
> "export" isn't among the recognised options. You may have missed this
> code fragment when removing the option from your patch.
I dropped "export" as we discussed on the IRC.
>
>> + 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;
>> + }
>> +
>> + if (strstr(filename, "://")) {
>
> Why this check? It means that any passed filename that doesn't contain
> "://" is silently ignored. Shouldn't an error be returned in this case?
> (Which would automatically happen if you called nfs_parse_uri()
> unconditionally.)
Exactly!! I follwed this chunk of code from NBD and the same doubt
came to my mind, but then I did not give it much thought. But since
you have noticed it, shouldn't the same logic apply to NBD?
>
>> + 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 +353,49 @@ 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 +438,40 @@ 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;
>> @@ -305,85 +479,83 @@ static int64_t nfs_client_open(NFSClient *client,
>> const char *filename,
>> file = g_strdup(strp);
>> *strp = 0;
>>
>> - client->context = nfs_init_context();
>> - if (client->context == NULL) {
>> - error_setg(errp, "Failed to init NFS context");
>> - goto fail;
>> + if (qemu_opt_get(opts, "uid")) {
>> + nfs_set_uid(client->context,
>> + qemu_opt_get_number(opts, "uid", getuid()));
>> }
>
> The patch puts this nicely together in a single hunk: You can't move the
> context initialisation to later, but then use it in nfs_set_uid() here.
> Same for the other options that you set before actually initialising the
> context.
*sigh* Yes, I fixed this. Very careless mistake!!
>
>> - 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, "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
>> +
>> + client->context = nfs_init_context();
>> + if (client->context == NULL) {
>> + error_setg(errp, "Failed to init NFS context");
>> + goto fail;
>> }
>>
>> - 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 +589,11 @@ 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 +602,17 @@ 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 +634,7 @@ 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;
>>
>> client->aio_context = qemu_get_aio_context();
>>
>> @@ -482,7 +642,9 @@ 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 = qemu_opts_to_qdict(opts, NULL);
>> +
>> + ret = nfs_client_open(client, options, O_CREAT, errp, 0);
>> if (ret < 0) {
>> goto out;
>> }
>
> This doesn't look right. The options that you're passing to
> nfs_client_open() now are create options (nfs_create_opts, i.e. only
> "size") and don't contain the host name etc. This information is passed
> in 'url', which is completely unused now.
I realised this after discussing with you on the IRC and now I am
using 'url' to fill up the QDict options and then passing them to the
nfs_client_open() function.
>> @@ -578,7 +740,7 @@ 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,
>
> This was just a quick review, I'll try to do a more thorough one when
> the big things are fixed.
No problem. I will send v2 and await another round of review.
Ashijeet
>
> Kevin