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Thu, 15 Feb 2024 13:05:45 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap2.dmz-prg2.suse.org with ESMTPSA id 0kcxCCkMzmWSFQAAn2gu4w (envelope-from ); Thu, 15 Feb 2024 13:05:45 +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: ee5ab304-cc02-11ee-8a4d-1f161083a0e0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1708002345; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=L9NcHDZsirisD0yciG+rBpMttYLBTYJ34tUyYEKGqh8=; b=Fa3l8KpEg+ehmFbS58CxlBh61ofDZoNquqBKccQwvm/ccCfzmOK5QDkMHUYW3+RT58RvmB FVejcuUkGK6+yvW12CshYcpvrZRJ1V7IgC9drPnC396TW5sYAKN1wH94WGvx7nnxwyvCBc Y6mCtYZR+rPH2YOyCIimXV1E6ZXlSt4= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1708002345; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=L9NcHDZsirisD0yciG+rBpMttYLBTYJ34tUyYEKGqh8=; b=Fa3l8KpEg+ehmFbS58CxlBh61ofDZoNquqBKccQwvm/ccCfzmOK5QDkMHUYW3+RT58RvmB FVejcuUkGK6+yvW12CshYcpvrZRJ1V7IgC9drPnC396TW5sYAKN1wH94WGvx7nnxwyvCBc Y6mCtYZR+rPH2YOyCIimXV1E6ZXlSt4= From: Juergen Gross To: xen-devel@lists.xenproject.org Cc: Juergen Gross , Wei Liu , Anthony PERARD , Jason Andryuk Subject: [PATCH v7 06/21] tools/xen-9pfsd: add 9pfs attach request support Date: Thu, 15 Feb 2024 14:04:54 +0100 Message-Id: <20240215130509.24008-7-jgross@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20240215130509.24008-1-jgross@suse.com> References: <20240215130509.24008-1-jgross@suse.com> MIME-Version: 1.0 Authentication-Results: smtp-out1.suse.de; none X-Spamd-Result: default: False [1.90 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; R_MISSING_CHARSET(2.50)[]; MIME_GOOD(-0.10)[text/plain]; TO_MATCH_ENVRCPT_ALL(0.00)[]; BROKEN_CONTENT_TYPE(1.50)[]; RCPT_COUNT_FIVE(0.00)[5]; RCVD_COUNT_THREE(0.00)[3]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; MID_CONTAINS_FROM(1.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:email]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_CC(0.00)[suse.com,xen.org,citrix.com,gmail.com]; RCVD_TLS_ALL(0.00)[]; BAYES_HAM(-3.00)[100.00%] 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) V7: - use EBADF instead of EBADFD (Andrew Cooper) - use strcpy() instead of strncpy() (Andrew Cooper) --- tools/9pfsd/io.c | 162 ++++++++++++++++++++++++++++++++++++++++ tools/9pfsd/xen-9pfsd.c | 6 ++ tools/9pfsd/xen-9pfsd.h | 14 ++++ 3 files changed, 182 insertions(+) diff --git a/tools/9pfsd/io.c b/tools/9pfsd/io.c index 839dd1112c..4c422b06ac 100644 --- a/tools/9pfsd/io.c +++ b/tools/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 +465,124 @@ 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; + + fidp = calloc(sizeof(*fidp) + strlen(path) + 1, 1); + if ( !fidp ) + return NULL; + + fidp->fid = fid; + strcpy(fidp->path, path); + + 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 = EBADF; + 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 +624,42 @@ 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 +719,10 @@ 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/9pfsd/xen-9pfsd.c b/tools/9pfsd/xen-9pfsd.c index 73b6c3a30e..b83b896bcc 100644 --- a/tools/9pfsd/xen-9pfsd.c +++ b/tools/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/9pfsd/xen-9pfsd.h b/tools/9pfsd/xen-9pfsd.h index 0cde0d2bb8..6c755411a7 100644 --- a/tools/9pfsd/xen-9pfsd.h +++ b/tools/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 */