From patchwork Mon Feb 5 10:49:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 13545236 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C632CC48295 for ; Mon, 5 Feb 2024 10:57:46 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.675837.1051453 (Exim 4.92) (envelope-from ) id 1rWwfT-00034x-H5; Mon, 05 Feb 2024 10:57:39 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 675837.1051453; Mon, 05 Feb 2024 10:57:39 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1rWwfT-00034m-DV; Mon, 05 Feb 2024 10:57:39 +0000 Received: by outflank-mailman (input) for mailman id 675837; Mon, 05 Feb 2024 10:57:38 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1rWwYn-0000qL-Pc for xen-devel@lists.xenproject.org; Mon, 05 Feb 2024 10:50:45 +0000 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 692a4a00-c414-11ee-98f5-efadbce2ee36; Mon, 05 Feb 2024 11:50:44 +0100 (CET) Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id AC6BA22100; Mon, 5 Feb 2024 10:50:43 +0000 (UTC) Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 8224E132DD; Mon, 5 Feb 2024 10:50:43 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id IPddHoO9wGUqNgAAD6G6ig (envelope-from ); Mon, 05 Feb 2024 10:50:43 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 692a4a00-c414-11ee-98f5-efadbce2ee36 From: Juergen Gross To: xen-devel@lists.xenproject.org Cc: Juergen Gross , Wei Liu , Anthony PERARD Subject: [PATCH v4 07/32] tools/xen-9pfsd: add 9pfs attach request support Date: Mon, 5 Feb 2024 11:49:36 +0100 Message-Id: <20240205105001.24171-8-jgross@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240205105001.24171-1-jgross@suse.com> References: <20240205105001.24171-1-jgross@suse.com> MIME-Version: 1.0 Authentication-Results: smtp-out1.suse.de; none X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[] X-Rspamd-Queue-Id: AC6BA22100 Add the attach request of the 9pfs protocol. This introduces the "fid" scheme of the 9pfs protocol. As this will be needed later, use a dedicated memory allocation function in alloc_fid() and prepare a fid reference count. For filling the qid data take the approach from the qemu 9pfs backend implementation. Signed-off-by: Juergen Gross Acked-by: Anthony PERARD Reviewed-by: Jason Andryuk --- V2: - make fill_qid() parameter stbuf const (Jason Andryuk) - free fids after disconnecting guest (Jason Andryuk) V3: - only store relative path in fid (Jason Andryuk) V4: - store a path directly usable by *at() functions in fid (Jason Andryuk) --- tools/xen-9pfsd/io.c | 164 ++++++++++++++++++++++++++++++++++++ tools/xen-9pfsd/xen-9pfsd.c | 6 ++ tools/xen-9pfsd/xen-9pfsd.h | 14 +++ 3 files changed, 184 insertions(+) diff --git a/tools/xen-9pfsd/io.c b/tools/xen-9pfsd/io.c index 839dd1112c..4f6acefc87 100644 --- a/tools/xen-9pfsd/io.c +++ b/tools/xen-9pfsd/io.c @@ -11,11 +11,14 @@ * before looking for the next request. */ +#include #include #include #include #include #include +#include +#include #include /* For cpu barriers. */ #include @@ -23,6 +26,7 @@ /* P9 protocol commands (response is either cmd+1 or P9_CMD_ERROR). */ #define P9_CMD_VERSION 100 +#define P9_CMD_ATTACH 104 #define P9_CMD_ERROR 107 #define P9_MIN_MSIZE 2048 @@ -461,6 +465,126 @@ static int fill_data(struct ring *ring, const char *fmt, ...) return pars; } +static struct p9_fid *find_fid(device *device, unsigned int fid) +{ + struct p9_fid *fidp; + + XEN_TAILQ_FOREACH(fidp, &device->fids, list) + { + if ( fidp->fid == fid ) + return fidp; + } + + return NULL; +} + +static struct p9_fid *alloc_fid_mem(device *device, unsigned int fid, + const char *path) +{ + struct p9_fid *fidp; + size_t pathlen; + + pathlen = strlen(path); + fidp = calloc(sizeof(*fidp) + pathlen + 1, 1); + if ( !fidp ) + return NULL; + + fidp->fid = fid; + strncpy(fidp->path, path, pathlen); + + return fidp; +} + +static struct p9_fid *alloc_fid(device *device, unsigned int fid, + const char *path) +{ + struct p9_fid *fidp = NULL; + + pthread_mutex_lock(&device->fid_mutex); + + if ( find_fid(device, fid) ) + { + errno = EBADFD; + goto out; + } + + if ( device->n_fids >= device->max_open_files ) + { + errno = EMFILE; + goto out; + } + + fidp = alloc_fid_mem(device, fid, path); + if ( !fidp ) + goto out; + + fidp->ref = 1; + XEN_TAILQ_INSERT_HEAD(&device->fids, fidp, list); + device->n_fids++; + + out: + pthread_mutex_unlock(&device->fid_mutex); + + return fidp; +} + +static void free_fid(device *device, struct p9_fid *fidp) +{ + if ( !fidp ) + return; + + pthread_mutex_lock(&device->fid_mutex); + + fidp->ref--; + if ( !fidp->ref ) + { + device->n_fids--; + XEN_TAILQ_REMOVE(&device->fids, fidp, list); + free(fidp); + } + + pthread_mutex_unlock(&device->fid_mutex); +} + +void free_fids(device *device) +{ + struct p9_fid *fidp; + + while ( (fidp = XEN_TAILQ_FIRST(&device->fids)) != NULL ) + { + XEN_TAILQ_REMOVE(&device->fids, fidp, list); + free(fidp); + } +} + +static const char *relpath_from_path(const char *path) +{ + if (!strcmp(path, "/")) + return "."; + + return (path[0] == '/') ? path + 1 : path; +} + +static int fill_qid(device *device, const char *path, struct p9_qid *qid, + const struct stat *stbuf) +{ + struct stat st; + + if ( !stbuf ) + { + if ( fstatat(device->root_fd, path, &st, 0) ) + return errno; + + stbuf = &st; + } + + qid->type = S_ISDIR(stbuf->st_mode) ? QID_TYPE_DIR : 0; + qid->version = stbuf->st_mtime ^ (stbuf->st_size << 8); + qid->path = stbuf->st_ino; + + return 0; +} + static void p9_error(struct ring *ring, uint16_t tag, uint32_t err) { unsigned int erroff; @@ -502,6 +626,42 @@ static void p9_version(struct ring *ring, struct p9_header *hdr) fill_buffer(ring, hdr->cmd + 1, hdr->tag, "US", &ring->max_size, version); } +static void p9_attach(struct ring *ring, struct p9_header *hdr) +{ + device *device = ring->device; + uint32_t fid; + uint32_t dummy_u32; + unsigned int dummy_uint; + struct p9_qid qid; + int ret; + + ret = fill_data(ring, "UUSSU", &fid, &dummy_u32, &dummy_uint, &dummy_uint, + &dummy_u32); + if ( ret != 5 ) + { + p9_error(ring, hdr->tag, errno); + return; + } + + device->root_fid = alloc_fid(device, fid, relpath_from_path("/")); + if ( !device->root_fid ) + { + p9_error(ring, hdr->tag, errno); + return; + } + + ret = fill_qid(device, device->root_fid->path, &qid, NULL); + if ( ret ) + { + free_fid(device, device->root_fid); + device->root_fid = NULL; + p9_error(ring, hdr->tag, ret); + return; + } + + fill_buffer(ring, hdr->cmd + 1, hdr->tag, "Q", &qid); +} + void *io_thread(void *arg) { struct ring *ring = arg; @@ -561,6 +721,10 @@ void *io_thread(void *arg) p9_version(ring, &hdr); break; + case P9_CMD_ATTACH: + p9_attach(ring, &hdr); + break; + default: syslog(LOG_DEBUG, "%u.%u sent unhandled command %u\n", ring->device->domid, ring->device->devid, hdr.cmd); diff --git a/tools/xen-9pfsd/xen-9pfsd.c b/tools/xen-9pfsd/xen-9pfsd.c index 73b6c3a30e..b83b896bcc 100644 --- a/tools/xen-9pfsd/xen-9pfsd.c +++ b/tools/xen-9pfsd/xen-9pfsd.c @@ -304,6 +304,9 @@ static device *new_device(unsigned int domid, unsigned int devid) return NULL; } + pthread_mutex_init(&device->fid_mutex, NULL); + XEN_TAILQ_INIT(&device->fids); + val = read_backend_node(device, "security_model"); if ( !val || strcmp(val, "none") ) { @@ -399,6 +402,8 @@ static void disconnect_guest(device *device) } device->num_rings = 0; + + free_fids(device); } static void close_device(device *device, enum xenbus_state state) @@ -482,6 +487,7 @@ static void remove_device(device *device) XEN_TAILQ_REMOVE(&devs, device, list); disconnect_guest(device); + pthread_mutex_destroy(&device->fid_mutex); free_device(device); } diff --git a/tools/xen-9pfsd/xen-9pfsd.h b/tools/xen-9pfsd/xen-9pfsd.h index 0cde0d2bb8..6c755411a7 100644 --- a/tools/xen-9pfsd/xen-9pfsd.h +++ b/tools/xen-9pfsd/xen-9pfsd.h @@ -21,6 +21,13 @@ struct p9_header { uint16_t tag; } __attribute__((packed)); +struct p9_fid { + XEN_TAILQ_ENTRY(struct p9_fid) list; + unsigned int fid; + unsigned int ref; + char path[]; +}; + typedef struct device device; struct ring { @@ -71,10 +78,17 @@ struct device { unsigned int num_rings; struct ring *ring[MAX_RINGS]; int root_fd; + + /* File system handling. */ + pthread_mutex_t fid_mutex; + XEN_TAILQ_HEAD(fidhead, struct p9_fid) fids; + struct p9_fid *root_fid; + unsigned int n_fids; }; extern xenevtchn_handle *xe; void *io_thread(void *arg); +void free_fids(device *device); #endif /* XEN_9PFSD_H */