[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] tools/xen-9pfsd: add 9pfs walk request support
commit 9615e40f4700f548ed77cd10c13c22b42d5f4a99 Author: Juergen Gross <jgross@xxxxxxxx> AuthorDate: Thu Feb 15 14:04:55 2024 +0100 Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CommitDate: Thu Feb 15 16:24:39 2024 +0000 tools/xen-9pfsd: add 9pfs walk request support Add the walk request of the 9pfs protocol. Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Acked-by: Anthony PERARD <anthony.perard@xxxxxxxxxx> Reviewed-by: Jason Andryuk <jandryuk@xxxxxxxxx> --- tools/9pfsd/io.c | 171 ++++++++++++++++++++++++++++++++++++++++++++++++ tools/9pfsd/xen-9pfsd.h | 1 + 2 files changed, 172 insertions(+) diff --git a/tools/9pfsd/io.c b/tools/9pfsd/io.c index 3fd4289f7c..98af20a21d 100644 --- a/tools/9pfsd/io.c +++ b/tools/9pfsd/io.c @@ -28,9 +28,11 @@ #define P9_CMD_VERSION 100 #define P9_CMD_ATTACH 104 #define P9_CMD_ERROR 107 +#define P9_CMD_WALK 110 #define P9_MIN_MSIZE 2048 #define P9_VERSION "9P2000.u" +#define P9_WALK_MAXELEM 16 struct p9_qid { uint8_t type; @@ -478,6 +480,21 @@ static struct p9_fid *find_fid(device *device, unsigned int fid) return NULL; } +static struct p9_fid *get_fid_ref(device *device, unsigned int fid) +{ + struct p9_fid *fidp; + + pthread_mutex_lock(&device->fid_mutex); + + fidp = find_fid(device, fid); + if ( fidp ) + fidp->ref++; + + pthread_mutex_unlock(&device->fid_mutex); + + return fidp; +} + static struct p9_fid *alloc_fid_mem(device *device, unsigned int fid, const char *path) { @@ -576,6 +593,10 @@ static int fill_qid(device *device, const char *path, struct p9_qid *qid, stbuf = &st; } + /* Don't allow symbolic links. */ + if ( S_ISLNK(stbuf->st_mode) ) + return EMLINK; + 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; @@ -583,6 +604,20 @@ static int fill_qid(device *device, const char *path, struct p9_qid *qid, return 0; } +static bool name_ok(const char *str) +{ + if ( !*str ) + return false; + + if ( strchr(str, '/' ) ) + return false; + + if ( !strcmp(str, "..") || !strcmp(str, ".") ) + return false; + + return true; +} + static void p9_error(struct ring *ring, uint16_t tag, uint32_t err) { unsigned int erroff; @@ -660,6 +695,138 @@ static void p9_attach(struct ring *ring, struct p9_header *hdr) fill_buffer(ring, hdr->cmd + 1, hdr->tag, "Q", &qid); } +static void p9_walk(struct ring *ring, struct p9_header *hdr) +{ + device *device = ring->device; + uint32_t fid; + uint32_t newfid; + struct p9_fid *fidp = NULL; + struct p9_qid *qids = NULL; + unsigned int n_names = 0; + unsigned int *names = NULL; + unsigned int walked = 0; + unsigned int i; + char *path = NULL; + unsigned int path_len; + int ret; + + ret = fill_data(ring, "UUaS", &fid, &newfid, &n_names, &names); + if ( n_names > P9_WALK_MAXELEM ) + { + p9_error(ring, hdr->tag, EINVAL); + goto out; + } + if ( ret != 3 + n_names ) + { + p9_error(ring, hdr->tag, errno); + goto out; + } + + fidp = get_fid_ref(device, fid); + if ( !fidp ) + { + p9_error(ring, hdr->tag, ENOENT); + goto out; + } + if ( fidp->opened ) + { + p9_error(ring, hdr->tag, EINVAL); + goto out; + } + + path_len = strlen(fidp->path) + 1; + for ( i = 0; i < n_names; i++ ) + { + if ( !name_ok(ring->str + names[i]) ) + { + p9_error(ring, hdr->tag, ENOENT); + goto out; + } + path_len += strlen(ring->str + names[i]) + 1; + } + path = calloc(path_len + 1, 1); + if ( !path ) + { + p9_error(ring, hdr->tag, ENOMEM); + goto out; + } + strcpy(path, fidp->path); + + if ( n_names ) + { + qids = calloc(n_names, sizeof(*qids)); + if ( !qids ) + { + p9_error(ring, hdr->tag, ENOMEM); + goto out; + } + for ( i = 0; i < n_names; i++ ) + { + strcat(path, "/"); + strcat(path, ring->str + names[i]); + ret = fill_qid(device, path, qids + i, NULL); + if ( ret ) + { + if ( !walked ) + { + p9_error(ring, hdr->tag, errno); + goto out; + } + break; + } + walked++; + } + } + + if ( walked == n_names ) + { + bool ok = false; + + if ( fid == newfid ) + { + struct p9_fid *new_fidp; + + pthread_mutex_lock(&device->fid_mutex); + + if ( fidp->ref != 2 ) + { + errno = EBUSY; + } + else + { + new_fidp = alloc_fid_mem(device, fid, path); + if ( new_fidp ) + { + new_fidp->ref = 2; + XEN_TAILQ_REMOVE(&device->fids, fidp, list); + XEN_TAILQ_INSERT_HEAD(&device->fids, new_fidp, list); + free(fidp); + fidp = new_fidp; + ok = true; + } + } + + pthread_mutex_unlock(&device->fid_mutex); + } + else + ok = alloc_fid(device, newfid, path); + + if ( !ok ) + { + p9_error(ring, hdr->tag, errno); + goto out; + } + } + + fill_buffer(ring, hdr->cmd + 1, hdr->tag, "aQ", &walked, qids); + + out: + free_fid(device, fidp); + free(qids); + free(path); + free(names); +} + void *io_thread(void *arg) { struct ring *ring = arg; @@ -723,6 +890,10 @@ void *io_thread(void *arg) p9_attach(ring, &hdr); break; + case P9_CMD_WALK: + p9_walk(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.h b/tools/9pfsd/xen-9pfsd.h index 6c755411a7..f01fffb0bb 100644 --- a/tools/9pfsd/xen-9pfsd.h +++ b/tools/9pfsd/xen-9pfsd.h @@ -25,6 +25,7 @@ struct p9_fid { XEN_TAILQ_ENTRY(struct p9_fid) list; unsigned int fid; unsigned int ref; + bool opened; char path[]; }; -- generated by git-patchbot for /home/xen/git/xen.git#staging
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