/* * Virtio 9p backend * * Copyright IBM, Corp. 2010 * * Authors: * Anthony Liguori * * This work is licensed under the terms of the GNU GPL, version 2. See * the COPYING file in the top-level directory. * */ /* * Not so fast! You might want to read the 9p developer docs first: * https://wiki.qemu.org/Documentation/9p */ #include "qemu/osdep.h" #ifdef CONFIG_LINUX #include #endif #include #include "hw/virtio/virtio.h" #include "qapi/error.h" #include "qemu/error-report.h" #include "qemu/iov.h" #include "qemu/main-loop.h" #include "qemu/sockets.h" #include "virtio-9p.h" #include "fsdev/qemu-fsdev.h" #include "9p-xattr.h" #include "9p-util.h" #include "coth.h" #include "trace.h" #include "migration/blocker.h" #include "qemu/xxhash.h" #include int open_fd_hw; int total_open_fd; static int open_fd_rc; enum { Oread = 0x00, Owrite = 0x01, Ordwr = 0x02, Oexec = 0x03, Oexcl = 0x04, Otrunc = 0x10, Orexec = 0x20, Orclose = 0x40, Oappend = 0x80, }; P9ARRAY_DEFINE_TYPE(V9fsPath, v9fs_path_free); static ssize_t pdu_marshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...) { ssize_t ret; va_list ap; va_start(ap, fmt); ret = pdu->s->transport->pdu_vmarshal(pdu, offset, fmt, ap); va_end(ap); return ret; } static ssize_t pdu_unmarshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...) { ssize_t ret; va_list ap; va_start(ap, fmt); ret = pdu->s->transport->pdu_vunmarshal(pdu, offset, fmt, ap); va_end(ap); return ret; } static int omode_to_uflags(int8_t mode) { int ret = 0; switch (mode & 3) { case Oread: ret = O_RDONLY; break; case Ordwr: ret = O_RDWR; break; case Owrite: ret = O_WRONLY; break; case Oexec: ret = O_RDONLY; break; } if (mode & Otrunc) { ret |= O_TRUNC; } if (mode & Oappend) { ret |= O_APPEND; } if (mode & Oexcl) { ret |= O_EXCL; } return ret; } typedef struct DotlOpenflagMap { int dotl_flag; int open_flag; } DotlOpenflagMap; static int dotl_to_open_flags(int flags) { int i; /* * We have same bits for P9_DOTL_READONLY, P9_DOTL_WRONLY * and P9_DOTL_NOACCESS */ int oflags = flags & O_ACCMODE; DotlOpenflagMap dotl_oflag_map[] = { { P9_DOTL_CREATE, O_CREAT }, { P9_DOTL_EXCL, O_EXCL }, { P9_DOTL_NOCTTY , O_NOCTTY }, { P9_DOTL_TRUNC, O_TRUNC }, { P9_DOTL_APPEND, O_APPEND }, { P9_DOTL_NONBLOCK, O_NONBLOCK } , { P9_DOTL_DSYNC, O_DSYNC }, { P9_DOTL_FASYNC, FASYNC }, #ifndef CONFIG_DARWIN { P9_DOTL_NOATIME, O_NOATIME }, /* * On Darwin, we could map to F_NOCACHE, which is * similar, but doesn't quite have the same * semantics. However, we don't support O_DIRECT * even on linux at the moment, so we just ignore * it here. */ { P9_DOTL_DIRECT, O_DIRECT }, #endif { P9_DOTL_LARGEFILE, O_LARGEFILE }, { P9_DOTL_DIRECTORY, O_DIRECTORY }, { P9_DOTL_NOFOLLOW, O_NOFOLLOW }, { P9_DOTL_SYNC, O_SYNC }, }; for (i = 0; i < ARRAY_SIZE(dotl_oflag_map); i++) { if (flags & dotl_oflag_map[i].dotl_flag) { oflags |= dotl_oflag_map[i].open_flag; } } return oflags; } void cred_init(FsCred *credp) { credp->fc_uid = -1; credp->fc_gid = -1; credp->fc_mode = -1; credp->fc_rdev = -1; } static int get_dotl_openflags(V9fsState *s, int oflags) { int flags; /* * Filter the client open flags */ flags = dotl_to_open_flags(oflags); flags &= ~(O_NOCTTY | O_ASYNC | O_CREAT); #ifndef CONFIG_DARWIN /* * Ignore direct disk access hint until the server supports it. */ flags &= ~O_DIRECT; #endif return flags; } void v9fs_path_init(V9fsPath *path) { path->data = NULL; path->size = 0; } void v9fs_path_free(V9fsPath *path) { g_free(path->data); path->data = NULL; path->size = 0; } void G_GNUC_PRINTF(2, 3) v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...) { va_list ap; v9fs_path_free(path); va_start(ap, fmt); /* Bump the size for including terminating NULL */ path->size = g_vasprintf(&path->data, fmt, ap) + 1; va_end(ap); } void v9fs_path_copy(V9fsPath *dst, const V9fsPath *src) { v9fs_path_free(dst); dst->size = src->size; dst->data = g_memdup(src->data, src->size); } int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath, const char *name, V9fsPath *path) { int err; err = s->ops->name_to_path(&s->ctx, dirpath, name, path); if (err < 0) { err = -errno; } return err; } /* * Return TRUE if s1 is an ancestor of s2. * * E.g. "a/b" is an ancestor of "a/b/c" but not of "a/bc/d". * As a special case, We treat s1 as ancestor of s2 if they are same! */ static int v9fs_path_is_ancestor(V9fsPath *s1, V9fsPath *s2) { if (!strncmp(s1->data, s2->data, s1->size - 1)) { if (s2->data[s1->size - 1] == '\0' || s2->data[s1->size - 1] == '/') { return 1; } } return 0; } static size_t v9fs_string_size(V9fsString *str) { return str->size; } /* * returns 0 if fid got re-opened, 1 if not, < 0 on error */ static int coroutine_fn v9fs_reopen_fid(V9fsPDU *pdu, V9fsFidState *f) { int err = 1; if (f->fid_type == P9_FID_FILE) { if (f->fs.fd == -1) { do { err = v9fs_co_open(pdu, f, f->open_flags); } while (err == -EINTR && !pdu->cancelled); } } else if (f->fid_type == P9_FID_DIR) { if (f->fs.dir.stream == NULL) { do { err = v9fs_co_opendir(pdu, f); } while (err == -EINTR && !pdu->cancelled); } } return err; } static V9fsFidState *coroutine_fn get_fid(V9fsPDU *pdu, int32_t fid) { int err; V9fsFidState *f; V9fsState *s = pdu->s; f = g_hash_table_lookup(s->fids, GINT_TO_POINTER(fid)); if (f) { BUG_ON(f->clunked); /* * Update the fid ref upfront so that * we don't get reclaimed when we yield * in open later. */ f->ref++; /* * check whether we need to reopen the * file. We might have closed the fd * while trying to free up some file * descriptors. */ err = v9fs_reopen_fid(pdu, f); if (err < 0) { f->ref--; return NULL; } /* * Mark the fid as referenced so that the LRU * reclaim won't close the file descriptor */ f->flags |= FID_REFERENCED; return f; } return NULL; } static V9fsFidState *alloc_fid(V9fsState *s, int32_t fid) { V9fsFidState *f; f = g_hash_table_lookup(s->fids, GINT_TO_POINTER(fid)); if (f) { /* If fid is already there return NULL */ BUG_ON(f->clunked); return NULL; } f = g_new0(V9fsFidState, 1); f->fid = fid; f->fid_type = P9_FID_NONE; f->ref = 1; /* * Mark the fid as referenced so that the LRU * reclaim won't close the file descriptor */ f->flags |= FID_REFERENCED; g_hash_table_insert(s->fids, GINT_TO_POINTER(fid), f); v9fs_readdir_init(s->proto_version, &f->fs.dir); v9fs_readdir_init(s->proto_version, &f->fs_reclaim.dir); return f; } static int coroutine_fn v9fs_xattr_fid_clunk(V9fsPDU *pdu, V9fsFidState *fidp) { int retval = 0; if (fidp->fs.xattr.xattrwalk_fid) { /* getxattr/listxattr fid */ goto free_value; } /* * if this is fid for setxattr. clunk should * result in setxattr localcall */ if (fidp->fs.xattr.len != fidp->fs.xattr.copied_len) { /* clunk after partial write */ retval = -EINVAL; goto free_out; } if (fidp->fs.xattr.len) { retval = v9fs_co_lsetxattr(pdu, &fidp->path, &fidp->fs.xattr.name, fidp->fs.xattr.value, fidp->fs.xattr.len, fidp->fs.xattr.flags); } else { retval = v9fs_co_lremovexattr(pdu, &fidp->path, &fidp->fs.xattr.name); } free_out: v9fs_string_free(&fidp->fs.xattr.name); free_value: g_free(fidp->fs.xattr.value); return retval; } static int coroutine_fn free_fid(V9fsPDU *pdu, V9fsFidState *fidp) { int retval = 0; if (fidp->fid_type == P9_FID_FILE) { /* If we reclaimed the fd no need to close */ if (fidp->fs.fd != -1) { retval = v9fs_co_close(pdu, &fidp->fs); } } else if (fidp->fid_type == P9_FID_DIR) { if (fidp->fs.dir.stream != NULL) { retval = v9fs_co_closedir(pdu, &fidp->fs); } } else if (fidp->fid_type == P9_FID_XATTR) { retval = v9fs_xattr_fid_clunk(pdu, fidp); } v9fs_path_free(&fidp->path); g_free(fidp); return retval; } static int coroutine_fn put_fid(V9fsPDU *pdu, V9fsFidState *fidp) { BUG_ON(!fidp->ref); fidp->ref--; /* * Don't free the fid if it is in reclaim list */ if (!fidp->ref && fidp->clunked) { if (fidp->fid == pdu->s->root_fid) { /* * if the clunked fid is root fid then we * have unmounted the fs on the client side. * delete the migration blocker. Ideally, this * should be hooked to transport close notification */ if (pdu->s->migration_blocker) { migrate_del_blocker(pdu->s->migration_blocker); error_free(pdu->s->migration_blocker); pdu->s->migration_blocker = NULL; } } return free_fid(pdu, fidp); } return 0; } static V9fsFidState *clunk_fid(V9fsState *s, int32_t fid) { V9fsFidState *fidp; /* TODO: Use g_hash_table_steal_extended() instead? */ fidp = g_hash_table_lookup(s->fids, GINT_TO_POINTER(fid)); if (fidp) { g_hash_table_remove(s->fids, GINT_TO_POINTER(fid)); fidp->clunked = true; return fidp; } return NULL; } void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu) { int reclaim_count = 0; V9fsState *s = pdu->s; V9fsFidState *f; GHashTableIter iter; gpointer fid; g_hash_table_iter_init(&iter, s->fids); QSLIST_HEAD(, V9fsFidState) reclaim_list = QSLIST_HEAD_INITIALIZER(reclaim_list); while (g_hash_table_iter_next(&iter, &fid, (gpointer *) &f)) { /* * Unlink fids cannot be reclaimed. Check * for them and skip them. Also skip fids * currently being operated on. */ if (f->ref || f->flags & FID_NON_RECLAIMABLE) { continue; } /* * if it is a recently referenced fid * we leave the fid untouched and clear the * reference bit. We come back to it later * in the next iteration. (a simple LRU without * moving list elements around) */ if (f->flags & FID_REFERENCED) { f->flags &= ~FID_REFERENCED; continue; } /* * Add fids to reclaim list. */ if (f->fid_type == P9_FID_FILE) { if (f->fs.fd != -1) { /* * Up the reference count so that * a clunk request won't free this fid */ f->ref++; QSLIST_INSERT_HEAD(&reclaim_list, f, reclaim_next); f->fs_reclaim.fd = f->fs.fd; f->fs.fd = -1; reclaim_count++; } } else if (f->fid_type == P9_FID_DIR) { if (f->fs.dir.stream != NULL) { /* * Up the reference count so that * a clunk request won't free this fid */ f->ref++; QSLIST_INSERT_HEAD(&reclaim_list, f, reclaim_next); f->fs_reclaim.dir.stream = f->fs.dir.stream; f->fs.dir.stream = NULL; reclaim_count++; } } if (reclaim_count >= open_fd_rc) { break; } } /* * Now close the fid in reclaim list. Free them if they * are already clunked. */ while (!QSLIST_EMPTY(&reclaim_list)) { f = QSLIST_FIRST(&reclaim_list); QSLIST_REMOVE(&reclaim_list, f, V9fsFidState, reclaim_next); if (f->fid_type == P9_FID_FILE) { v9fs_co_close(pdu, &f->fs_reclaim); } else if (f->fid_type == P9_FID_DIR) { v9fs_co_closedir(pdu, &f->fs_reclaim); } /* * Now drop the fid reference, free it * if clunked. */ put_fid(pdu, f); } } /* * This is used when a path is removed from the directory tree. Any * fids that still reference it must not be closed from then on, since * they cannot be reopened. */ static int coroutine_fn v9fs_mark_fids_unreclaim(V9fsPDU *pdu, V9fsPath *path) { int err = 0; V9fsState *s = pdu->s; V9fsFidState *fidp; gpointer fid; GHashTableIter iter; /* * The most common case is probably that we have exactly one * fid for the given path, so preallocate exactly one. */ g_autoptr(GArray) to_reopen = g_array_sized_new(FALSE, FALSE, sizeof(V9fsFidState *), 1); gint i; g_hash_table_iter_init(&iter, s->fids); /* * We iterate over the fid table looking for the entries we need * to reopen, and store them in to_reopen. This is because * v9fs_reopen_fid() and put_fid() yield. This allows the fid table * to be modified in the meantime, invalidating our iterator. */ while (g_hash_table_iter_next(&iter, &fid, (gpointer *) &fidp)) { if (fidp->path.size == path->size && !memcmp(fidp->path.data, path->data, path->size)) { /* * Ensure the fid survives a potential clunk request during * v9fs_reopen_fid or put_fid. */ fidp->ref++; fidp->flags |= FID_NON_RECLAIMABLE; g_array_append_val(to_reopen, fidp); } } for (i = 0; i < to_reopen->len; i++) { fidp = g_array_index(to_reopen, V9fsFidState*, i); /* reopen the file/dir if already closed */ err = v9fs_reopen_fid(pdu, fidp); if (err < 0) { break; } } for (i = 0; i < to_reopen->len; i++) { put_fid(pdu, g_array_index(to_reopen, V9fsFidState*, i)); } return err; } static void coroutine_fn virtfs_reset(V9fsPDU *pdu) { V9fsState *s = pdu->s; V9fsFidState *fidp; GList *freeing; /* * Get a list of all the values (fid states) in the table, which * we then... */ g_autoptr(GList) fids = g_hash_table_get_values(s->fids); /* ... remove from the table, taking over ownership. */ g_hash_table_steal_all(s->fids); /* * This allows us to release our references to them asynchronously without * iterating over the hash table and risking iterator invalidation * through concurrent modifications. */ for (freeing = fids; freeing; freeing = freeing->next) { fidp = freeing->data; fidp->ref++; fidp->clunked = true; put_fid(pdu, fidp); } } #define P9_QID_TYPE_DIR 0x80 #define P9_QID_TYPE_SYMLINK 0x02 #define P9_STAT_MODE_DIR 0x80000000 #define P9_STAT_MODE_APPEND 0x40000000 #define P9_STAT_MODE_EXCL 0x20000000 #define P9_STAT_MODE_MOUNT 0x10000000 #define P9_STAT_MODE_AUTH 0x08000000 #define P9_STAT_MODE_TMP 0x04000000 #define P9_STAT_MODE_SYMLINK 0x02000000 #define P9_STAT_MODE_LINK 0x01000000 #define P9_STAT_MODE_DEVICE 0x00800000 #define P9_STAT_MODE_NAMED_PIPE 0x00200000 #define P9_STAT_MODE_SOCKET 0x00100000 #define P9_STAT_MODE_SETUID 0x00080000 #define P9_STAT_MODE_SETGID 0x00040000 #define P9_STAT_MODE_SETVTX 0x00010000 #define P9_STAT_MODE_TYPE_BITS (P9_STAT_MODE_DIR | \ P9_STAT_MODE_SYMLINK | \ P9_STAT_MODE_LINK | \ P9_STAT_MODE_DEVICE | \ P9_STAT_MODE_NAMED_PIPE | \ P9_STAT_MODE_SOCKET) /* Mirrors all bits of a byte. So e.g. binary 10100000 would become 00000101. */ static inline uint8_t mirror8bit(uint8_t byte) { return (byte * 0x0202020202ULL & 0x010884422010ULL) % 1023; } /* Same as mirror8bit() just for a 64 bit data type instead for a byte. */ static inline uint64_t mirror64bit(uint64_t value) { return ((uint64_t)mirror8bit(value & 0xff) << 56) | ((uint64_t)mirror8bit((value >> 8) & 0xff) << 48) | ((uint64_t)mirror8bit((value >> 16) & 0xff) << 40) | ((uint64_t)mirror8bit((value >> 24) & 0xff) << 32) | ((uint64_t)mirror8bit((value >> 32) & 0xff) << 24) | ((uint64_t)mirror8bit((value >> 40) & 0xff) << 16) | ((uint64_t)mirror8bit((value >> 48) & 0xff) << 8) | ((uint64_t)mirror8bit((value >> 56) & 0xff)); } /* * Parameter k for the Exponential Golomb algorihm to be used. * * The smaller this value, the smaller the minimum bit count for the Exp. * Golomb generated affixes will be (at lowest index) however for the * price of having higher maximum bit count of generated affixes (at highest * index). Likewise increasing this parameter yields in smaller maximum bit * count for the price of having higher minimum bit count. * * In practice that means: a good value for k depends on the expected amount * of devices to be exposed by one export. For a small amount of devices k * should be small, for a large amount of devices k might be increased * instead. The default of k=0 should be fine for most users though. * * IMPORTANT: In case this ever becomes a runtime parameter; the value of * k should not change as long as guest is still running! Because that would * cause completely different inode numbers to be generated on guest. */ #define EXP_GOLOMB_K 0 /** * expGolombEncode() - Exponential Golomb algorithm for arbitrary k * (including k=0). * * @n: natural number (or index) of the prefix to be generated * (1, 2, 3, ...) * @k: parameter k of Exp. Golomb algorithm to be used * (see comment on EXP_GOLOMB_K macro for details about k) * Return: prefix for given @n and @k * * The Exponential Golomb algorithm generates prefixes (NOT suffixes!) * with growing length and with the mathematical property of being * "prefix-free". The latter means the generated prefixes can be prepended * in front of arbitrary numbers and the resulting concatenated numbers are * guaranteed to be always unique. * * This is a minor adjustment to the original Exp. Golomb algorithm in the * sense that lowest allowed index (@n) starts with 1, not with zero. */ static VariLenAffix expGolombEncode(uint64_t n, int k) { const uint64_t value = n + (1 << k) - 1; const int bits = (int) log2(value) + 1; return (VariLenAffix) { .type = AffixType_Prefix, .value = value, .bits = bits + MAX((bits - 1 - k), 0) }; } /** * invertAffix() - Converts a suffix into a prefix, or a prefix into a suffix. * @affix: either suffix or prefix to be inverted * Return: inversion of passed @affix * * Simply mirror all bits of the affix value, for the purpose to preserve * respectively the mathematical "prefix-free" or "suffix-free" property * after the conversion. * * If a passed prefix is suitable to create unique numbers, then the * returned suffix is suitable to create unique numbers as well (and vice * versa). */ static VariLenAffix invertAffix(const VariLenAffix *affix) { return (VariLenAffix) { .type = (affix->type == AffixType_Suffix) ? AffixType_Prefix : AffixType_Suffix, .value = mirror64bit(affix->value) >> ((sizeof(affix->value) * 8) - affix->bits), .bits = affix->bits }; } /** * affixForIndex() - Generates suffix numbers with "suffix-free" property. * @index: natural number (or index) of the suffix to be generated * (1, 2, 3, ...) * Return: Suffix suitable to assemble unique number. * * This is just a wrapper function on top of the Exp. Golomb algorithm. * * Since the Exp. Golomb algorithm generates prefixes, but we need suffixes, * this function converts the Exp. Golomb prefixes into appropriate suffixes * which are still suitable for generating unique numbers. */ static VariLenAffix affixForIndex(uint64_t index) { VariLenAffix prefix; prefix = expGolombEncode(index, EXP_GOLOMB_K); return invertAffix(&prefix); /* convert prefix to suffix */ } static uint32_t qpp_hash(QppEntry e) { return qemu_xxhash4(e.ino_prefix, e.dev); } static uint32_t qpf_hash(QpfEntry e) { return qemu_xxhash4(e.ino, e.dev); } static bool qpd_cmp_func(const void *obj, const void *userp) { const QpdEntry *e1 = obj, *e2 = userp; return e1->dev == e2->dev; } static bool qpp_cmp_func(const void *obj, const void *userp) { const QppEntry *e1 = obj, *e2 = userp; return e1->dev == e2->dev && e1->ino_prefix == e2->ino_prefix; } static bool qpf_cmp_func(const void *obj, const void *userp) { const QpfEntry *e1 = obj, *e2 = userp; return e1->dev == e2->dev && e1->ino == e2->ino; } static void qp_table_remove(void *p, uint32_t h, void *up) { g_free(p); } static void qp_table_destroy(struct qht *ht) { if (!ht || !ht->map) { return; } qht_iter(ht, qp_table_remove, NULL); qht_destroy(ht); } static void qpd_table_init(struct qht *ht) { qht_init(ht, qpd_cmp_func, 1, QHT_MODE_AUTO_RESIZE); } static void qpp_table_init(struct qht *ht) { qht_init(ht, qpp_cmp_func, 1, QHT_MODE_AUTO_RESIZE); } static void qpf_table_init(struct qht *ht) { qht_init(ht, qpf_cmp_func, 1 << 16, QHT_MODE_AUTO_RESIZE); } /* * Returns how many (high end) bits of inode numbers of the passed fs * device shall be used (in combination with the device number) to * generate hash values for qpp_table entries. * * This function is required if variable length suffixes are used for inode * number mapping on guest level. Since a device may end up having multiple * entries in qpp_table, each entry most probably with a different suffix * length, we thus need this function in conjunction with qpd_table to * "agree" about a fix amount of bits (per device) to be always used for * generating hash values for the purpose of accessing qpp_table in order * get consistent behaviour when accessing qpp_table. */ static int qid_inode_prefix_hash_bits(V9fsPDU *pdu, dev_t dev) { QpdEntry lookup = { .dev = dev }, *val; uint32_t hash = dev; VariLenAffix affix; val = qht_lookup(&pdu->s->qpd_table, &lookup, hash); if (!val) { val = g_new0(QpdEntry, 1); *val = lookup; affix = affixForIndex(pdu->s->qp_affix_next); val->prefix_bits = affix.bits; qht_insert(&pdu->s->qpd_table, val, hash, NULL); pdu->s->qp_ndevices++; } return val->prefix_bits; } /* * Slow / full mapping host inode nr -> guest inode nr. * * This function performs a slower and much more costly remapping of an * original file inode number on host to an appropriate different inode * number on guest. For every (dev, inode) combination on host a new * sequential number is generated, cached and exposed as inode number on * guest. * * This is just a "last resort" fallback solution if the much faster/cheaper * qid_path_suffixmap() failed. In practice this slow / full mapping is not * expected ever to be used at all though. * * See qid_path_suffixmap() for details * */ static int qid_path_fullmap(V9fsPDU *pdu, const struct stat *stbuf, uint64_t *path) { QpfEntry lookup = { .dev = stbuf->st_dev, .ino = stbuf->st_ino }, *val; uint32_t hash = qpf_hash(lookup); VariLenAffix affix; val = qht_lookup(&pdu->s->qpf_table, &lookup, hash); if (!val) { if (pdu->s->qp_fullpath_next == 0) { /* no more files can be mapped :'( */ error_report_once( "9p: No more prefixes available for remapping inodes from " "host to guest." ); return -ENFILE; } val = g_new0(QpfEntry, 1); *val = lookup; /* new unique inode and device combo */ affix = affixForIndex( 1ULL << (sizeof(pdu->s->qp_affix_next) * 8) ); val->path = (pdu->s->qp_fullpath_next++ << affix.bits) | affix.value; pdu->s->qp_fullpath_next &= ((1ULL << (64 - affix.bits)) - 1); qht_insert(&pdu->s->qpf_table, val, hash, NULL); } *path = val->path; return 0; } /* * Quick mapping host inode nr -> guest inode nr. * * This function performs quick remapping of an original file inode number * on host to an appropriate different inode number on guest. This remapping * of inodes is required to avoid inode nr collisions on guest which would * happen if the 9p export contains more than 1 exported file system (or * more than 1 file system data set), because unlike on host level where the * files would have different device nrs, all files exported by 9p would * share the same device nr on guest (the device nr of the virtual 9p device * that is). * * Inode remapping is performed by chopping off high end bits of the original * inode number from host, shifting the result upwards and then assigning a * generated suffix number for the low end bits, where the same suffix number * will be shared by all inodes with the same device id AND the same high end * bits that have been chopped off. That approach utilizes the fact that inode * numbers very likely share the same high end bits (i.e. due to their common * sequential generation by file systems) and hence we only have to generate * and track a very limited amount of suffixes in practice due to that. * * We generate variable size suffixes for that purpose. The 1st generated * suffix will only have 1 bit and hence we only need to chop off 1 bit from * the original inode number. The subsequent suffixes being generated will * grow in (bit) size subsequently, i.e. the 2nd and 3rd suffix being * generated will have 3 bits and hence we have to chop off 3 bits from their * original inodes, and so on. That approach of using variable length suffixes * (i.e. over fixed size ones) utilizes the fact that in practice only a very * limited amount of devices are shared by the same export (e.g. typically * less than 2 dozen devices per 9p export), so in practice we need to chop * off less bits than with fixed size prefixes and yet are flexible to add * new devices at runtime below host's export directory at any time without * having to reboot guest nor requiring to reconfigure guest for that. And due * to the very limited amount of original high end bits that we chop off that * way, the total amount of suffixes we need to generate is less than by using * fixed size prefixes and hence it also improves performance of the inode * remapping algorithm, and finally has the nice side effect that the inode * numbers on guest will be much smaller & human friendly. ;-) */ static int qid_path_suffixmap(V9fsPDU *pdu, const struct stat *stbuf, uint64_t *path) { const int ino_hash_bits = qid_inode_prefix_hash_bits(pdu, stbuf->st_dev); QppEntry lookup = { .dev = stbuf->st_dev, .ino_prefix = (uint16_t) (stbuf->st_ino >> (64 - ino_hash_bits)) }, *val; uint32_t hash = qpp_hash(lookup); val = qht_lookup(&pdu->s->qpp_table, &lookup, hash); if (!val) { if (pdu->s->qp_affix_next == 0) { /* we ran out of affixes */ warn_report_once( "9p: Potential degraded performance of inode remapping" ); return -ENFILE; } val = g_new0(QppEntry, 1); *val = lookup; /* new unique inode affix and device combo */ val->qp_affix_index = pdu->s->qp_affix_next++; val->qp_affix = affixForIndex(val->qp_affix_index); qht_insert(&pdu->s->qpp_table, val, hash, NULL); } /* assuming generated affix to be suffix type, not prefix */ *path = (stbuf->st_ino << val->qp_affix.bits) | val->qp_affix.value; return 0; } static int stat_to_qid(V9fsPDU *pdu, const struct stat *stbuf, V9fsQID *qidp) { int err; size_t size; if (pdu->s->ctx.export_flags & V9FS_REMAP_INODES) { /* map inode+device to qid path (fast path) */ err = qid_path_suffixmap(pdu, stbuf, &qidp->path); if (err == -ENFILE) { /* fast path didn't work, fall back to full map */ err = qid_path_fullmap(pdu, stbuf, &qidp->path); } if (err) { return err; } } else { if (pdu->s->dev_id != stbuf->st_dev) { if (pdu->s->ctx.export_flags & V9FS_FORBID_MULTIDEVS) { error_report_once( "9p: Multiple devices detected in same VirtFS export. " "Access of guest to additional devices is (partly) " "denied due to virtfs option 'multidevs=forbid' being " "effective." ); return -ENODEV; } else { warn_report_once( "9p: Multiple devices detected in same VirtFS export, " "which might lead to file ID collisions and severe " "misbehaviours on guest! You should either use a " "separate export for each device shared from host or " "use virtfs option 'multidevs=remap'!" ); } } memset(&qidp->path, 0, sizeof(qidp->path)); size = MIN(sizeof(stbuf->st_ino), sizeof(qidp->path)); memcpy(&qidp->path, &stbuf->st_ino, size); } qidp->version = stbuf->st_mtime ^ (stbuf->st_size << 8); qidp->type = 0; if (S_ISDIR(stbuf->st_mode)) { qidp->type |= P9_QID_TYPE_DIR; } if (S_ISLNK(stbuf->st_mode)) { qidp->type |= P9_QID_TYPE_SYMLINK; } return 0; } V9fsPDU *pdu_alloc(V9fsState *s) { V9fsPDU *pdu = NULL; if (!QLIST_EMPTY(&s->free_list)) { pdu = QLIST_FIRST(&s->free_list); QLIST_REMOVE(pdu, next); QLIST_INSERT_HEAD(&s->active_list, pdu, next); } return pdu; } void pdu_free(V9fsPDU *pdu) { V9fsState *s = pdu->s; g_assert(!pdu->cancelled); QLIST_REMOVE(pdu, next); QLIST_INSERT_HEAD(&s->free_list, pdu, next); } static void coroutine_fn pdu_complete(V9fsPDU *pdu, ssize_t len) { int8_t id = pdu->id + 1; /* Response */ V9fsState *s = pdu->s; int ret; /* * The 9p spec requires that successfully cancelled pdus receive no reply. * Sending a reply would confuse clients because they would * assume that any EINTR is the actual result of the operation, * rather than a consequence of the cancellation. However, if * the operation completed (succesfully or with an error other * than caused be cancellation), we do send out that reply, both * for efficiency and to avoid confusing the rest of the state machine * that assumes passing a non-error here will mean a successful * transmission of the reply. */ bool discard = pdu->cancelled && len == -EINTR; if (discard) { trace_v9fs_rcancel(pdu->tag, pdu->id); pdu->size = 0; goto out_notify; } if (len < 0) { int err = -len; len = 7; if (s->proto_version != V9FS_PROTO_2000L) { V9fsString str; str.data = strerror(err); str.size = strlen(str.data); ret = pdu_marshal(pdu, len, "s", &str); if (ret < 0) { goto out_notify; } len += ret; id = P9_RERROR; } else { err = errno_to_dotl(err); } ret = pdu_marshal(pdu, len, "d", err); if (ret < 0) { goto out_notify; } len += ret; if (s->proto_version == V9FS_PROTO_2000L) { id = P9_RLERROR; } trace_v9fs_rerror(pdu->tag, pdu->id, err); /* Trace ERROR */ } /* fill out the header */ if (pdu_marshal(pdu, 0, "dbw", (int32_t)len, id, pdu->tag) < 0) { goto out_notify; } /* keep these in sync */ pdu->size = len; pdu->id = id; out_notify: pdu->s->transport->push_and_notify(pdu); /* Now wakeup anybody waiting in flush for this request */ if (!qemu_co_queue_next(&pdu->complete)) { pdu_free(pdu); } } static mode_t v9mode_to_mode(uint32_t mode, V9fsString *extension) { mode_t ret; ret = mode & 0777; if (mode & P9_STAT_MODE_DIR) { ret |= S_IFDIR; } if (mode & P9_STAT_MODE_SYMLINK) { ret |= S_IFLNK; } if (mode & P9_STAT_MODE_SOCKET) { ret |= S_IFSOCK; } if (mode & P9_STAT_MODE_NAMED_PIPE) { ret |= S_IFIFO; } if (mode & P9_STAT_MODE_DEVICE) { if (extension->size && extension->data[0] == 'c') { ret |= S_IFCHR; } else { ret |= S_IFBLK; } } if (!(ret & ~0777)) { ret |= S_IFREG; } if (mode & P9_STAT_MODE_SETUID) { ret |= S_ISUID; } if (mode & P9_STAT_MODE_SETGID) { ret |= S_ISGID; } if (mode & P9_STAT_MODE_SETVTX) { ret |= S_ISVTX; } return ret; } static int donttouch_stat(V9fsStat *stat) { if (stat->type == -1 && stat->dev == -1 && stat->qid.type == 0xff && stat->qid.version == (uint32_t) -1 && stat->qid.path == (uint64_t) -1 && stat->mode == -1 && stat->atime == -1 && stat->mtime == -1 && stat->length == -1 && !stat->name.size && !stat->uid.size && !stat->gid.size && !stat->muid.size && stat->n_uid == -1 && stat->n_gid == -1 && stat->n_muid == -1) { return 1; } return 0; } static void v9fs_stat_init(V9fsStat *stat) { v9fs_string_init(&stat->name); v9fs_string_init(&stat->uid); v9fs_string_init(&stat->gid); v9fs_string_init(&stat->muid); v9fs_string_init(&stat->extension); } static void v9fs_stat_free(V9fsStat *stat) { v9fs_string_free(&stat->name); v9fs_string_free(&stat->uid); v9fs_string_free(&stat->gid); v9fs_string_free(&stat->muid); v9fs_string_free(&stat->extension); } static uint32_t stat_to_v9mode(const struct stat *stbuf) { uint32_t mode; mode = stbuf->st_mode & 0777; if (S_ISDIR(stbuf->st_mode)) { mode |= P9_STAT_MODE_DIR; } if (S_ISLNK(stbuf->st_mode)) { mode |= P9_STAT_MODE_SYMLINK; } if (S_ISSOCK(stbuf->st_mode)) { mode |= P9_STAT_MODE_SOCKET; } if (S_ISFIFO(stbuf->st_mode)) { mode |= P9_STAT_MODE_NAMED_PIPE; } if (S_ISBLK(stbuf->st_mode) || S_ISCHR(stbuf->st_mode)) { mode |= P9_STAT_MODE_DEVICE; } if (stbuf->st_mode & S_ISUID) { mode |= P9_STAT_MODE_SETUID; } if (stbuf->st_mode & S_ISGID) { mode |= P9_STAT_MODE_SETGID; } if (stbuf->st_mode & S_ISVTX) { mode |= P9_STAT_MODE_SETVTX; } return mode; } static int coroutine_fn stat_to_v9stat(V9fsPDU *pdu, V9fsPath *path, const char *basename, const struct stat *stbuf, V9fsStat *v9stat) { int err; memset(v9stat, 0, sizeof(*v9stat)); err = stat_to_qid(pdu, stbuf, &v9stat->qid); if (err < 0) { return err; } v9stat->mode = stat_to_v9mode(stbuf); v9stat->atime = stbuf->st_atime; v9stat->mtime = stbuf->st_mtime; v9stat->length = stbuf->st_size; v9fs_string_free(&v9stat->uid); v9fs_string_free(&v9stat->gid); v9fs_string_free(&v9stat->muid); v9stat->n_uid = stbuf->st_uid; v9stat->n_gid = stbuf->st_gid; v9stat->n_muid = 0; v9fs_string_free(&v9stat->extension); if (v9stat->mode & P9_STAT_MODE_SYMLINK) { err = v9fs_co_readlink(pdu, path, &v9stat->extension); if (err < 0) { return err; } } else if (v9stat->mode & P9_STAT_MODE_DEVICE) { v9fs_string_sprintf(&v9stat->extension, "%c %u %u", S_ISCHR(stbuf->st_mode) ? 'c' : 'b', major(stbuf->st_rdev), minor(stbuf->st_rdev)); } else if (S_ISDIR(stbuf->st_mode) || S_ISREG(stbuf->st_mode)) { v9fs_string_sprintf(&v9stat->extension, "%s %lu", "HARDLINKCOUNT", (unsigned long)stbuf->st_nlink); } v9fs_string_sprintf(&v9stat->name, "%s", basename); v9stat->size = 61 + v9fs_string_size(&v9stat->name) + v9fs_string_size(&v9stat->uid) + v9fs_string_size(&v9stat->gid) + v9fs_string_size(&v9stat->muid) + v9fs_string_size(&v9stat->extension); return 0; } #define P9_STATS_MODE 0x00000001ULL #define P9_STATS_NLINK 0x00000002ULL #define P9_STATS_UID 0x00000004ULL #define P9_STATS_GID 0x00000008ULL #define P9_STATS_RDEV 0x00000010ULL #define P9_STATS_ATIME 0x00000020ULL #define P9_STATS_MTIME 0x00000040ULL #define P9_STATS_CTIME 0x00000080ULL #define P9_STATS_INO 0x00000100ULL #define P9_STATS_SIZE 0x00000200ULL #define P9_STATS_BLOCKS 0x00000400ULL #define P9_STATS_BTIME 0x00000800ULL #define P9_STATS_GEN 0x00001000ULL #define P9_STATS_DATA_VERSION 0x00002000ULL #define P9_STATS_BASIC 0x000007ffULL /* Mask for fields up to BLOCKS */ #define P9_STATS_ALL 0x00003fffULL /* Mask for All fields above */ /** * blksize_to_iounit() - Block size exposed to 9p client. * Return: block size * * @pdu: 9p client request * @blksize: host filesystem's block size * * Convert host filesystem's block size into an appropriate block size for * 9p client (guest OS side). The value returned suggests an "optimum" block * size for 9p I/O, i.e. to maximize performance. */ static int32_t blksize_to_iounit(const V9fsPDU *pdu, int32_t blksize) { int32_t iounit = 0; V9fsState *s = pdu->s; /* * iounit should be multiples of blksize (host filesystem block size) * as well as less than (client msize - P9_IOHDRSZ) */ if (blksize) { iounit = QEMU_ALIGN_DOWN(s->msize - P9_IOHDRSZ, blksize); } if (!iounit) { iounit = s->msize - P9_IOHDRSZ; } return iounit; } static int32_t stat_to_iounit(const V9fsPDU *pdu, const struct stat *stbuf) { return blksize_to_iounit(pdu, stbuf->st_blksize); } static int stat_to_v9stat_dotl(V9fsPDU *pdu, const struct stat *stbuf, V9fsStatDotl *v9lstat) { memset(v9lstat, 0, sizeof(*v9lstat)); v9lstat->st_mode = stbuf->st_mode; v9lstat->st_nlink = stbuf->st_nlink; v9lstat->st_uid = stbuf->st_uid; v9lstat->st_gid = stbuf->st_gid; v9lstat->st_rdev = host_dev_to_dotl_dev(stbuf->st_rdev); v9lstat->st_size = stbuf->st_size; v9lstat->st_blksize = stat_to_iounit(pdu, stbuf); v9lstat->st_blocks = stbuf->st_blocks; v9lstat->st_atime_sec = stbuf->st_atime; v9lstat->st_mtime_sec = stbuf->st_mtime; v9lstat->st_ctime_sec = stbuf->st_ctime; #ifdef CONFIG_DARWIN v9lstat->st_atime_nsec = stbuf->st_atimespec.tv_nsec; v9lstat->st_mtime_nsec = stbuf->st_mtimespec.tv_nsec; v9lstat->st_ctime_nsec = stbuf->st_ctimespec.tv_nsec; #else v9lstat->st_atime_nsec = stbuf->st_atim.tv_nsec; v9lstat->st_mtime_nsec = stbuf->st_mtim.tv_nsec; v9lstat->st_ctime_nsec = stbuf->st_ctim.tv_nsec; #endif /* Currently we only support BASIC fields in stat */ v9lstat->st_result_mask = P9_STATS_BASIC; return stat_to_qid(pdu, stbuf, &v9lstat->qid); } static void print_sg(struct iovec *sg, int cnt) { int i; printf("sg[%d]: {", cnt); for (i = 0; i < cnt; i++) { if (i) { printf(", "); } printf("(%p, %zd)", sg[i].iov_base, sg[i].iov_len); } printf("}\n"); } /* Will call this only for path name based fid */ static void v9fs_fix_path(V9fsPath *dst, V9fsPath *src, int len) { V9fsPath str; v9fs_path_init(&str); v9fs_path_copy(&str, dst); v9fs_path_sprintf(dst, "%s%s", src->data, str.data + len); v9fs_path_free(&str); } static inline bool is_ro_export(FsContext *ctx) { return ctx->export_flags & V9FS_RDONLY; } static void coroutine_fn v9fs_version(void *opaque) { ssize_t err; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; V9fsString version; size_t offset = 7; v9fs_string_init(&version); err = pdu_unmarshal(pdu, offset, "ds", &s->msize, &version); if (err < 0) { goto out; } trace_v9fs_version(pdu->tag, pdu->id, s->msize, version.data); virtfs_reset(pdu); if (!strcmp(version.data, "9P2000.u")) { s->proto_version = V9FS_PROTO_2000U; } else if (!strcmp(version.data, "9P2000.L")) { s->proto_version = V9FS_PROTO_2000L; } else { v9fs_string_sprintf(&version, "unknown"); /* skip min. msize check, reporting invalid version has priority */ goto marshal; } if (s->msize < P9_MIN_MSIZE) { err = -EMSGSIZE; error_report( "9pfs: Client requested msize < minimum msize (" stringify(P9_MIN_MSIZE) ") supported by this server." ); goto out; } /* 8192 is the default msize of Linux clients */ if (s->msize <= 8192 && !(s->ctx.export_flags & V9FS_NO_PERF_WARN)) { warn_report_once( "9p: degraded performance: a reasonable high msize should be " "chosen on client/guest side (chosen msize is <= 8192). See " "https://wiki.qemu.org/Documentation/9psetup#msize for details." ); } marshal: err = pdu_marshal(pdu, offset, "ds", s->msize, &version); if (err < 0) { goto out; } err += offset; trace_v9fs_version_return(pdu->tag, pdu->id, s->msize, version.data); out: pdu_complete(pdu, err); v9fs_string_free(&version); } static void coroutine_fn v9fs_attach(void *opaque) { V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; int32_t fid, afid, n_uname; V9fsString uname, aname; V9fsFidState *fidp; size_t offset = 7; V9fsQID qid; ssize_t err; struct stat stbuf; v9fs_string_init(&uname); v9fs_string_init(&aname); err = pdu_unmarshal(pdu, offset, "ddssd", &fid, &afid, &uname, &aname, &n_uname); if (err < 0) { goto out_nofid; } trace_v9fs_attach(pdu->tag, pdu->id, fid, afid, uname.data, aname.data); fidp = alloc_fid(s, fid); if (fidp == NULL) { err = -EINVAL; goto out_nofid; } fidp->uid = n_uname; err = v9fs_co_name_to_path(pdu, NULL, "/", &fidp->path); if (err < 0) { err = -EINVAL; clunk_fid(s, fid); goto out; } err = v9fs_co_lstat(pdu, &fidp->path, &stbuf); if (err < 0) { err = -EINVAL; clunk_fid(s, fid); goto out; } err = stat_to_qid(pdu, &stbuf, &qid); if (err < 0) { err = -EINVAL; clunk_fid(s, fid); goto out; } /* * disable migration if we haven't done already. * attach could get called multiple times for the same export. */ if (!s->migration_blocker) { error_setg(&s->migration_blocker, "Migration is disabled when VirtFS export path '%s' is mounted in the guest using mount_tag '%s'", s->ctx.fs_root ? s->ctx.fs_root : "NULL", s->tag); err = migrate_add_blocker(s->migration_blocker, NULL); if (err < 0) { error_free(s->migration_blocker); s->migration_blocker = NULL; clunk_fid(s, fid); goto out; } s->root_fid = fid; } err = pdu_marshal(pdu, offset, "Q", &qid); if (err < 0) { clunk_fid(s, fid); goto out; } err += offset; memcpy(&s->root_st, &stbuf, sizeof(stbuf)); trace_v9fs_attach_return(pdu->tag, pdu->id, qid.type, qid.version, qid.path); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); v9fs_string_free(&uname); v9fs_string_free(&aname); } static void coroutine_fn v9fs_stat(void *opaque) { int32_t fid; V9fsStat v9stat; ssize_t err = 0; size_t offset = 7; struct stat stbuf; V9fsFidState *fidp; V9fsPDU *pdu = opaque; char *basename; err = pdu_unmarshal(pdu, offset, "d", &fid); if (err < 0) { goto out_nofid; } trace_v9fs_stat(pdu->tag, pdu->id, fid); fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -ENOENT; goto out_nofid; } err = v9fs_co_lstat(pdu, &fidp->path, &stbuf); if (err < 0) { goto out; } basename = g_path_get_basename(fidp->path.data); err = stat_to_v9stat(pdu, &fidp->path, basename, &stbuf, &v9stat); g_free(basename); if (err < 0) { goto out; } err = pdu_marshal(pdu, offset, "wS", 0, &v9stat); if (err < 0) { v9fs_stat_free(&v9stat); goto out; } trace_v9fs_stat_return(pdu->tag, pdu->id, v9stat.mode, v9stat.atime, v9stat.mtime, v9stat.length); err += offset; v9fs_stat_free(&v9stat); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); } static void coroutine_fn v9fs_getattr(void *opaque) { int32_t fid; size_t offset = 7; ssize_t retval = 0; struct stat stbuf; V9fsFidState *fidp; uint64_t request_mask; V9fsStatDotl v9stat_dotl; V9fsPDU *pdu = opaque; retval = pdu_unmarshal(pdu, offset, "dq", &fid, &request_mask); if (retval < 0) { goto out_nofid; } trace_v9fs_getattr(pdu->tag, pdu->id, fid, request_mask); fidp = get_fid(pdu, fid); if (fidp == NULL) { retval = -ENOENT; goto out_nofid; } /* * Currently we only support BASIC fields in stat, so there is no * need to look at request_mask. */ retval = v9fs_co_lstat(pdu, &fidp->path, &stbuf); if (retval < 0) { goto out; } retval = stat_to_v9stat_dotl(pdu, &stbuf, &v9stat_dotl); if (retval < 0) { goto out; } /* fill st_gen if requested and supported by underlying fs */ if (request_mask & P9_STATS_GEN) { retval = v9fs_co_st_gen(pdu, &fidp->path, stbuf.st_mode, &v9stat_dotl); switch (retval) { case 0: /* we have valid st_gen: update result mask */ v9stat_dotl.st_result_mask |= P9_STATS_GEN; break; case -EINTR: /* request cancelled, e.g. by Tflush */ goto out; default: /* failed to get st_gen: not fatal, ignore */ break; } } retval = pdu_marshal(pdu, offset, "A", &v9stat_dotl); if (retval < 0) { goto out; } retval += offset; trace_v9fs_getattr_return(pdu->tag, pdu->id, v9stat_dotl.st_result_mask, v9stat_dotl.st_mode, v9stat_dotl.st_uid, v9stat_dotl.st_gid); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, retval); } /* Attribute flags */ #define P9_ATTR_MODE (1 << 0) #define P9_ATTR_UID (1 << 1) #define P9_ATTR_GID (1 << 2) #define P9_ATTR_SIZE (1 << 3) #define P9_ATTR_ATIME (1 << 4) #define P9_ATTR_MTIME (1 << 5) #define P9_ATTR_CTIME (1 << 6) #define P9_ATTR_ATIME_SET (1 << 7) #define P9_ATTR_MTIME_SET (1 << 8) #define P9_ATTR_MASK 127 static void coroutine_fn v9fs_setattr(void *opaque) { int err = 0; int32_t fid; V9fsFidState *fidp; size_t offset = 7; V9fsIattr v9iattr; V9fsPDU *pdu = opaque; err = pdu_unmarshal(pdu, offset, "dI", &fid, &v9iattr); if (err < 0) { goto out_nofid; } trace_v9fs_setattr(pdu->tag, pdu->id, fid, v9iattr.valid, v9iattr.mode, v9iattr.uid, v9iattr.gid, v9iattr.size, v9iattr.atime_sec, v9iattr.mtime_sec); fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -EINVAL; goto out_nofid; } if (v9iattr.valid & P9_ATTR_MODE) { err = v9fs_co_chmod(pdu, &fidp->path, v9iattr.mode); if (err < 0) { goto out; } } if (v9iattr.valid & (P9_ATTR_ATIME | P9_ATTR_MTIME)) { struct timespec times[2]; if (v9iattr.valid & P9_ATTR_ATIME) { if (v9iattr.valid & P9_ATTR_ATIME_SET) { times[0].tv_sec = v9iattr.atime_sec; times[0].tv_nsec = v9iattr.atime_nsec; } else { times[0].tv_nsec = UTIME_NOW; } } else { times[0].tv_nsec = UTIME_OMIT; } if (v9iattr.valid & P9_ATTR_MTIME) { if (v9iattr.valid & P9_ATTR_MTIME_SET) { times[1].tv_sec = v9iattr.mtime_sec; times[1].tv_nsec = v9iattr.mtime_nsec; } else { times[1].tv_nsec = UTIME_NOW; } } else { times[1].tv_nsec = UTIME_OMIT; } err = v9fs_co_utimensat(pdu, &fidp->path, times); if (err < 0) { goto out; } } /* * If the only valid entry in iattr is ctime we can call * chown(-1,-1) to update the ctime of the file */ if ((v9iattr.valid & (P9_ATTR_UID | P9_ATTR_GID)) || ((v9iattr.valid & P9_ATTR_CTIME) && !((v9iattr.valid & P9_ATTR_MASK) & ~P9_ATTR_CTIME))) { if (!(v9iattr.valid & P9_ATTR_UID)) { v9iattr.uid = -1; } if (!(v9iattr.valid & P9_ATTR_GID)) { v9iattr.gid = -1; } err = v9fs_co_chown(pdu, &fidp->path, v9iattr.uid, v9iattr.gid); if (err < 0) { goto out; } } if (v9iattr.valid & (P9_ATTR_SIZE)) { err = v9fs_co_truncate(pdu, &fidp->path, v9iattr.size); if (err < 0) { goto out; } } err = offset; trace_v9fs_setattr_return(pdu->tag, pdu->id); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); } static int v9fs_walk_marshal(V9fsPDU *pdu, uint16_t nwnames, V9fsQID *qids) { int i; ssize_t err; size_t offset = 7; err = pdu_marshal(pdu, offset, "w", nwnames); if (err < 0) { return err; } offset += err; for (i = 0; i < nwnames; i++) { err = pdu_marshal(pdu, offset, "Q", &qids[i]); if (err < 0) { return err; } offset += err; } return offset; } static bool name_is_illegal(const char *name) { return !*name || strchr(name, '/') != NULL; } static bool same_stat_id(const struct stat *a, const struct stat *b) { return a->st_dev == b->st_dev && a->st_ino == b->st_ino; } static void coroutine_fn v9fs_walk(void *opaque) { int name_idx, nwalked; g_autofree V9fsQID *qids = NULL; int i, err = 0, any_err = 0; V9fsPath dpath, path; P9ARRAY_REF(V9fsPath) pathes = NULL; uint16_t nwnames; struct stat stbuf, fidst; g_autofree struct stat *stbufs = NULL; size_t offset = 7; int32_t fid, newfid; P9ARRAY_REF(V9fsString) wnames = NULL; V9fsFidState *fidp; V9fsFidState *newfidp = NULL; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; V9fsQID qid; err = pdu_unmarshal(pdu, offset, "ddw", &fid, &newfid, &nwnames); if (err < 0) { pdu_complete(pdu, err); return; } offset += err; trace_v9fs_walk(pdu->tag, pdu->id, fid, newfid, nwnames); if (nwnames > P9_MAXWELEM) { err = -EINVAL; goto out_nofid; } if (nwnames) { P9ARRAY_NEW(V9fsString, wnames, nwnames); qids = g_new0(V9fsQID, nwnames); stbufs = g_new0(struct stat, nwnames); P9ARRAY_NEW(V9fsPath, pathes, nwnames); for (i = 0; i < nwnames; i++) { err = pdu_unmarshal(pdu, offset, "s", &wnames[i]); if (err < 0) { goto out_nofid; } if (name_is_illegal(wnames[i].data)) { err = -ENOENT; goto out_nofid; } offset += err; } } fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -ENOENT; goto out_nofid; } v9fs_path_init(&dpath); v9fs_path_init(&path); /* * Both dpath and path initially point to fidp. * Needed to handle request with nwnames == 0 */ v9fs_path_copy(&dpath, &fidp->path); v9fs_path_copy(&path, &fidp->path); /* * To keep latency (i.e. overall execution time for processing this * Twalk client request) as small as possible, run all the required fs * driver code altogether inside the following block. */ v9fs_co_run_in_worker({ nwalked = 0; if (v9fs_request_cancelled(pdu)) { any_err |= err = -EINTR; break; } err = s->ops->lstat(&s->ctx, &dpath, &fidst); if (err < 0) { any_err |= err = -errno; break; } stbuf = fidst; for (; nwalked < nwnames; nwalked++) { if (v9fs_request_cancelled(pdu)) { any_err |= err = -EINTR; break; } if (!same_stat_id(&pdu->s->root_st, &stbuf) || strcmp("..", wnames[nwalked].data)) { err = s->ops->name_to_path(&s->ctx, &dpath, wnames[nwalked].data, &pathes[nwalked]); if (err < 0) { any_err |= err = -errno; break; } if (v9fs_request_cancelled(pdu)) { any_err |= err = -EINTR; break; } err = s->ops->lstat(&s->ctx, &pathes[nwalked], &stbuf); if (err < 0) { any_err |= err = -errno; break; } stbufs[nwalked] = stbuf; v9fs_path_copy(&dpath, &pathes[nwalked]); } } }); /* * Handle all the rest of this Twalk request on main thread ... * * NOTE: -EINTR is an exception where we deviate from the protocol spec * and simply send a (R)Lerror response instead of bothering to assemble * a (deducted) Rwalk response; because -EINTR is always the result of a * Tflush request, so client would no longer wait for a response in this * case anyway. */ if ((err < 0 && !nwalked) || err == -EINTR) { goto out; } any_err |= err = stat_to_qid(pdu, &fidst, &qid); if (err < 0 && !nwalked) { goto out; } stbuf = fidst; /* reset dpath and path */ v9fs_path_copy(&dpath, &fidp->path); v9fs_path_copy(&path, &fidp->path); for (name_idx = 0; name_idx < nwalked; name_idx++) { if (!same_stat_id(&pdu->s->root_st, &stbuf) || strcmp("..", wnames[name_idx].data)) { stbuf = stbufs[name_idx]; any_err |= err = stat_to_qid(pdu, &stbuf, &qid); if (err < 0) { break; } v9fs_path_copy(&path, &pathes[name_idx]); v9fs_path_copy(&dpath, &path); } memcpy(&qids[name_idx], &qid, sizeof(qid)); } if (any_err < 0) { if (!name_idx) { /* don't send any QIDs, send Rlerror instead */ goto out; } else { /* send QIDs (not Rlerror), but fid MUST remain unaffected */ goto send_qids; } } if (fid == newfid) { if (fidp->fid_type != P9_FID_NONE) { err = -EINVAL; goto out; } v9fs_path_write_lock(s); v9fs_path_copy(&fidp->path, &path); v9fs_path_unlock(s); } else { newfidp = alloc_fid(s, newfid); if (newfidp == NULL) { err = -EINVAL; goto out; } newfidp->uid = fidp->uid; v9fs_path_copy(&newfidp->path, &path); } send_qids: err = v9fs_walk_marshal(pdu, name_idx, qids); trace_v9fs_walk_return(pdu->tag, pdu->id, name_idx, qids); out: put_fid(pdu, fidp); if (newfidp) { put_fid(pdu, newfidp); } v9fs_path_free(&dpath); v9fs_path_free(&path); out_nofid: pdu_complete(pdu, err); } static int32_t coroutine_fn get_iounit(V9fsPDU *pdu, V9fsPath *path) { struct statfs stbuf; int err = v9fs_co_statfs(pdu, path, &stbuf); return blksize_to_iounit(pdu, (err >= 0) ? stbuf.f_bsize : 0); } static void coroutine_fn v9fs_open(void *opaque) { int flags; int32_t fid; int32_t mode; V9fsQID qid; int iounit = 0; ssize_t err = 0; size_t offset = 7; struct stat stbuf; V9fsFidState *fidp; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; if (s->proto_version == V9FS_PROTO_2000L) { err = pdu_unmarshal(pdu, offset, "dd", &fid, &mode); } else { uint8_t modebyte; err = pdu_unmarshal(pdu, offset, "db", &fid, &modebyte); mode = modebyte; } if (err < 0) { goto out_nofid; } trace_v9fs_open(pdu->tag, pdu->id, fid, mode); fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -ENOENT; goto out_nofid; } if (fidp->fid_type != P9_FID_NONE) { err = -EINVAL; goto out; } err = v9fs_co_lstat(pdu, &fidp->path, &stbuf); if (err < 0) { goto out; } err = stat_to_qid(pdu, &stbuf, &qid); if (err < 0) { goto out; } if (S_ISDIR(stbuf.st_mode)) { err = v9fs_co_opendir(pdu, fidp); if (err < 0) { goto out; } fidp->fid_type = P9_FID_DIR; err = pdu_marshal(pdu, offset, "Qd", &qid, 0); if (err < 0) { goto out; } err += offset; } else { if (s->proto_version == V9FS_PROTO_2000L) { flags = get_dotl_openflags(s, mode); } else { flags = omode_to_uflags(mode); } if (is_ro_export(&s->ctx)) { if (mode & O_WRONLY || mode & O_RDWR || mode & O_APPEND || mode & O_TRUNC) { err = -EROFS; goto out; } } err = v9fs_co_open(pdu, fidp, flags); if (err < 0) { goto out; } fidp->fid_type = P9_FID_FILE; fidp->open_flags = flags; if (flags & O_EXCL) { /* * We let the host file system do O_EXCL check * We should not reclaim such fd */ fidp->flags |= FID_NON_RECLAIMABLE; } iounit = get_iounit(pdu, &fidp->path); err = pdu_marshal(pdu, offset, "Qd", &qid, iounit); if (err < 0) { goto out; } err += offset; } trace_v9fs_open_return(pdu->tag, pdu->id, qid.type, qid.version, qid.path, iounit); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); } static void coroutine_fn v9fs_lcreate(void *opaque) { int32_t dfid, flags, mode; gid_t gid; ssize_t err = 0; ssize_t offset = 7; V9fsString name; V9fsFidState *fidp; struct stat stbuf; V9fsQID qid; int32_t iounit; V9fsPDU *pdu = opaque; v9fs_string_init(&name); err = pdu_unmarshal(pdu, offset, "dsddd", &dfid, &name, &flags, &mode, &gid); if (err < 0) { goto out_nofid; } trace_v9fs_lcreate(pdu->tag, pdu->id, dfid, flags, mode, gid); if (name_is_illegal(name.data)) { err = -ENOENT; goto out_nofid; } if (!strcmp(".", name.data) || !strcmp("..", name.data)) { err = -EEXIST; goto out_nofid; } fidp = get_fid(pdu, dfid); if (fidp == NULL) { err = -ENOENT; goto out_nofid; } if (fidp->fid_type != P9_FID_NONE) { err = -EINVAL; goto out; } flags = get_dotl_openflags(pdu->s, flags); err = v9fs_co_open2(pdu, fidp, &name, gid, flags | O_CREAT, mode, &stbuf); if (err < 0) { goto out; } fidp->fid_type = P9_FID_FILE; fidp->open_flags = flags; if (flags & O_EXCL) { /* * We let the host file system do O_EXCL check * We should not reclaim such fd */ fidp->flags |= FID_NON_RECLAIMABLE; } iounit = get_iounit(pdu, &fidp->path); err = stat_to_qid(pdu, &stbuf, &qid); if (err < 0) { goto out; } err = pdu_marshal(pdu, offset, "Qd", &qid, iounit); if (err < 0) { goto out; } err += offset; trace_v9fs_lcreate_return(pdu->tag, pdu->id, qid.type, qid.version, qid.path, iounit); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); v9fs_string_free(&name); } static void coroutine_fn v9fs_fsync(void *opaque) { int err; int32_t fid; int datasync; size_t offset = 7; V9fsFidState *fidp; V9fsPDU *pdu = opaque; err = pdu_unmarshal(pdu, offset, "dd", &fid, &datasync); if (err < 0) { goto out_nofid; } trace_v9fs_fsync(pdu->tag, pdu->id, fid, datasync); fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -ENOENT; goto out_nofid; } err = v9fs_co_fsync(pdu, fidp, datasync); if (!err) { err = offset; } put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); } static void coroutine_fn v9fs_clunk(void *opaque) { int err; int32_t fid; size_t offset = 7; V9fsFidState *fidp; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; err = pdu_unmarshal(pdu, offset, "d", &fid); if (err < 0) { goto out_nofid; } trace_v9fs_clunk(pdu->tag, pdu->id, fid); fidp = clunk_fid(s, fid); if (fidp == NULL) { err = -ENOENT; goto out_nofid; } /* * Bump the ref so that put_fid will * free the fid. */ fidp->ref++; err = put_fid(pdu, fidp); if (!err) { err = offset; } out_nofid: pdu_complete(pdu, err); } /* * Create a QEMUIOVector for a sub-region of PDU iovecs * * @qiov: uninitialized QEMUIOVector * @skip: number of bytes to skip from beginning of PDU * @size: number of bytes to include * @is_write: true - write, false - read * * The resulting QEMUIOVector has heap-allocated iovecs and must be cleaned up * with qemu_iovec_destroy(). */ static void v9fs_init_qiov_from_pdu(QEMUIOVector *qiov, V9fsPDU *pdu, size_t skip, size_t size, bool is_write) { QEMUIOVector elem; struct iovec *iov; unsigned int niov; if (is_write) { pdu->s->transport->init_out_iov_from_pdu(pdu, &iov, &niov, size + skip); } else { pdu->s->transport->init_in_iov_from_pdu(pdu, &iov, &niov, size + skip); } qemu_iovec_init_external(&elem, iov, niov); qemu_iovec_init(qiov, niov); qemu_iovec_concat(qiov, &elem, skip, size); } static int v9fs_xattr_read(V9fsState *s, V9fsPDU *pdu, V9fsFidState *fidp, uint64_t off, uint32_t max_count) { ssize_t err; size_t offset = 7; uint64_t read_count; QEMUIOVector qiov_full; if (fidp->fs.xattr.len < off) { read_count = 0; } else { read_count = fidp->fs.xattr.len - off; } if (read_count > max_count) { read_count = max_count; } err = pdu_marshal(pdu, offset, "d", read_count); if (err < 0) { return err; } offset += err; v9fs_init_qiov_from_pdu(&qiov_full, pdu, offset, read_count, false); err = v9fs_pack(qiov_full.iov, qiov_full.niov, 0, ((char *)fidp->fs.xattr.value) + off, read_count); qemu_iovec_destroy(&qiov_full); if (err < 0) { return err; } offset += err; return offset; } static int coroutine_fn v9fs_do_readdir_with_stat(V9fsPDU *pdu, V9fsFidState *fidp, uint32_t max_count) { V9fsPath path; V9fsStat v9stat; int len, err = 0; int32_t count = 0; struct stat stbuf; off_t saved_dir_pos; struct dirent *dent; /* save the directory position */ saved_dir_pos = v9fs_co_telldir(pdu, fidp); if (saved_dir_pos < 0) { return saved_dir_pos; } while (1) { v9fs_path_init(&path); v9fs_readdir_lock(&fidp->fs.dir); err = v9fs_co_readdir(pdu, fidp, &dent); if (err || !dent) { break; } err = v9fs_co_name_to_path(pdu, &fidp->path, dent->d_name, &path); if (err < 0) { break; } err = v9fs_co_lstat(pdu, &path, &stbuf); if (err < 0) { break; } err = stat_to_v9stat(pdu, &path, dent->d_name, &stbuf, &v9stat); if (err < 0) { break; } if ((count + v9stat.size + 2) > max_count) { v9fs_readdir_unlock(&fidp->fs.dir); /* Ran out of buffer. Set dir back to old position and return */ v9fs_co_seekdir(pdu, fidp, saved_dir_pos); v9fs_stat_free(&v9stat); v9fs_path_free(&path); return count; } /* 11 = 7 + 4 (7 = start offset, 4 = space for storing count) */ len = pdu_marshal(pdu, 11 + count, "S", &v9stat); v9fs_readdir_unlock(&fidp->fs.dir); if (len < 0) { v9fs_co_seekdir(pdu, fidp, saved_dir_pos); v9fs_stat_free(&v9stat); v9fs_path_free(&path); return len; } count += len; v9fs_stat_free(&v9stat); v9fs_path_free(&path); saved_dir_pos = qemu_dirent_off(dent); } v9fs_readdir_unlock(&fidp->fs.dir); v9fs_path_free(&path); if (err < 0) { return err; } return count; } static void coroutine_fn v9fs_read(void *opaque) { int32_t fid; uint64_t off; ssize_t err = 0; int32_t count = 0; size_t offset = 7; uint32_t max_count; V9fsFidState *fidp; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; err = pdu_unmarshal(pdu, offset, "dqd", &fid, &off, &max_count); if (err < 0) { goto out_nofid; } trace_v9fs_read(pdu->tag, pdu->id, fid, off, max_count); fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -EINVAL; goto out_nofid; } if (fidp->fid_type == P9_FID_DIR) { if (s->proto_version != V9FS_PROTO_2000U) { warn_report_once( "9p: bad client: T_read request on directory only expected " "with 9P2000.u protocol version" ); err = -EOPNOTSUPP; goto out; } if (off == 0) { v9fs_co_rewinddir(pdu, fidp); } count = v9fs_do_readdir_with_stat(pdu, fidp, max_count); if (count < 0) { err = count; goto out; } err = pdu_marshal(pdu, offset, "d", count); if (err < 0) { goto out; } err += offset + count; } else if (fidp->fid_type == P9_FID_FILE) { QEMUIOVector qiov_full; QEMUIOVector qiov; int32_t len; v9fs_init_qiov_from_pdu(&qiov_full, pdu, offset + 4, max_count, false); qemu_iovec_init(&qiov, qiov_full.niov); do { qemu_iovec_reset(&qiov); qemu_iovec_concat(&qiov, &qiov_full, count, qiov_full.size - count); if (0) { print_sg(qiov.iov, qiov.niov); } /* Loop in case of EINTR */ do { len = v9fs_co_preadv(pdu, fidp, qiov.iov, qiov.niov, off); if (len >= 0) { off += len; count += len; } } while (len == -EINTR && !pdu->cancelled); if (len < 0) { /* IO error return the error */ err = len; goto out_free_iovec; } } while (count < max_count && len > 0); err = pdu_marshal(pdu, offset, "d", count); if (err < 0) { goto out_free_iovec; } err += offset + count; out_free_iovec: qemu_iovec_destroy(&qiov); qemu_iovec_destroy(&qiov_full); } else if (fidp->fid_type == P9_FID_XATTR) { err = v9fs_xattr_read(s, pdu, fidp, off, max_count); } else { err = -EINVAL; } trace_v9fs_read_return(pdu->tag, pdu->id, count, err); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); } /** * v9fs_readdir_response_size() - Returns size required in Rreaddir response * for the passed dirent @name. * * @name: directory entry's name (i.e. file name, directory name) * Return: required size in bytes */ size_t v9fs_readdir_response_size(V9fsString *name) { /* * Size of each dirent on the wire: size of qid (13) + size of offset (8) * size of type (1) + size of name.size (2) + strlen(name.data) */ return 24 + v9fs_string_size(name); } static void v9fs_free_dirents(struct V9fsDirEnt *e) { struct V9fsDirEnt *next = NULL; for (; e; e = next) { next = e->next; g_free(e->dent); g_free(e->st); g_free(e); } } static int coroutine_fn v9fs_do_readdir(V9fsPDU *pdu, V9fsFidState *fidp, off_t offset, int32_t max_count) { size_t size; V9fsQID qid; V9fsString name; int len, err = 0; int32_t count = 0; off_t off; struct dirent *dent; struct stat *st; struct V9fsDirEnt *entries = NULL; /* * inode remapping requires the device id, which in turn might be * different for different directory entries, so if inode remapping is * enabled we have to make a full stat for each directory entry */ const bool dostat = pdu->s->ctx.export_flags & V9FS_REMAP_INODES; /* * Fetch all required directory entries altogether on a background IO * thread from fs driver. We don't want to do that for each entry * individually, because hopping between threads (this main IO thread * and background IO driver thread) would sum up to huge latencies. */ count = v9fs_co_readdir_many(pdu, fidp, &entries, offset, max_count, dostat); if (count < 0) { err = count; count = 0; goto out; } count = 0; for (struct V9fsDirEnt *e = entries; e; e = e->next) { dent = e->dent; if (pdu->s->ctx.export_flags & V9FS_REMAP_INODES) { st = e->st; /* e->st should never be NULL, but just to be sure */ if (!st) { err = -1; break; } /* remap inode */ err = stat_to_qid(pdu, st, &qid); if (err < 0) { break; } } else { /* * Fill up just the path field of qid because the client uses * only that. To fill the entire qid structure we will have * to stat each dirent found, which is expensive. For the * latter reason we don't call stat_to_qid() here. Only drawback * is that no multi-device export detection of stat_to_qid() * would be done and provided as error to the user here. But * user would get that error anyway when accessing those * files/dirs through other ways. */ size = MIN(sizeof(dent->d_ino), sizeof(qid.path)); memcpy(&qid.path, &dent->d_ino, size); /* Fill the other fields with dummy values */ qid.type = 0; qid.version = 0; } off = qemu_dirent_off(dent); v9fs_string_init(&name); v9fs_string_sprintf(&name, "%s", dent->d_name); /* 11 = 7 + 4 (7 = start offset, 4 = space for storing count) */ len = pdu_marshal(pdu, 11 + count, "Qqbs", &qid, off, dent->d_type, &name); v9fs_string_free(&name); if (len < 0) { err = len; break; } count += len; } out: v9fs_free_dirents(entries); if (err < 0) { return err; } return count; } static void coroutine_fn v9fs_readdir(void *opaque) { int32_t fid; V9fsFidState *fidp; ssize_t retval = 0; size_t offset = 7; uint64_t initial_offset; int32_t count; uint32_t max_count; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; retval = pdu_unmarshal(pdu, offset, "dqd", &fid, &initial_offset, &max_count); if (retval < 0) { goto out_nofid; } trace_v9fs_readdir(pdu->tag, pdu->id, fid, initial_offset, max_count); /* Enough space for a R_readdir header: size[4] Rreaddir tag[2] count[4] */ if (max_count > s->msize - 11) { max_count = s->msize - 11; warn_report_once( "9p: bad client: T_readdir with count > msize - 11" ); } fidp = get_fid(pdu, fid); if (fidp == NULL) { retval = -EINVAL; goto out_nofid; } if (!fidp->fs.dir.stream) { retval = -EINVAL; goto out; } if (s->proto_version != V9FS_PROTO_2000L) { warn_report_once( "9p: bad client: T_readdir request only expected with 9P2000.L " "protocol version" ); retval = -EOPNOTSUPP; goto out; } count = v9fs_do_readdir(pdu, fidp, (off_t) initial_offset, max_count); if (count < 0) { retval = count; goto out; } retval = pdu_marshal(pdu, offset, "d", count); if (retval < 0) { goto out; } retval += count + offset; trace_v9fs_readdir_return(pdu->tag, pdu->id, count, retval); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, retval); } static int v9fs_xattr_write(V9fsState *s, V9fsPDU *pdu, V9fsFidState *fidp, uint64_t off, uint32_t count, struct iovec *sg, int cnt) { int i, to_copy; ssize_t err = 0; uint64_t write_count; size_t offset = 7; if (fidp->fs.xattr.len < off) { return -ENOSPC; } write_count = fidp->fs.xattr.len - off; if (write_count > count) { write_count = count; } err = pdu_marshal(pdu, offset, "d", write_count); if (err < 0) { return err; } err += offset; fidp->fs.xattr.copied_len += write_count; /* * Now copy the content from sg list */ for (i = 0; i < cnt; i++) { if (write_count > sg[i].iov_len) { to_copy = sg[i].iov_len; } else { to_copy = write_count; } memcpy((char *)fidp->fs.xattr.value + off, sg[i].iov_base, to_copy); /* updating vs->off since we are not using below */ off += to_copy; write_count -= to_copy; } return err; } static void coroutine_fn v9fs_write(void *opaque) { ssize_t err; int32_t fid; uint64_t off; uint32_t count; int32_t len = 0; int32_t total = 0; size_t offset = 7; V9fsFidState *fidp; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; QEMUIOVector qiov_full; QEMUIOVector qiov; err = pdu_unmarshal(pdu, offset, "dqd", &fid, &off, &count); if (err < 0) { pdu_complete(pdu, err); return; } offset += err; v9fs_init_qiov_from_pdu(&qiov_full, pdu, offset, count, true); trace_v9fs_write(pdu->tag, pdu->id, fid, off, count, qiov_full.niov); fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -EINVAL; goto out_nofid; } if (fidp->fid_type == P9_FID_FILE) { if (fidp->fs.fd == -1) { err = -EINVAL; goto out; } } else if (fidp->fid_type == P9_FID_XATTR) { /* * setxattr operation */ err = v9fs_xattr_write(s, pdu, fidp, off, count, qiov_full.iov, qiov_full.niov); goto out; } else { err = -EINVAL; goto out; } qemu_iovec_init(&qiov, qiov_full.niov); do { qemu_iovec_reset(&qiov); qemu_iovec_concat(&qiov, &qiov_full, total, qiov_full.size - total); if (0) { print_sg(qiov.iov, qiov.niov); } /* Loop in case of EINTR */ do { len = v9fs_co_pwritev(pdu, fidp, qiov.iov, qiov.niov, off); if (len >= 0) { off += len; total += len; } } while (len == -EINTR && !pdu->cancelled); if (len < 0) { /* IO error return the error */ err = len; goto out_qiov; } } while (total < count && len > 0); offset = 7; err = pdu_marshal(pdu, offset, "d", total); if (err < 0) { goto out_qiov; } err += offset; trace_v9fs_write_return(pdu->tag, pdu->id, total, err); out_qiov: qemu_iovec_destroy(&qiov); out: put_fid(pdu, fidp); out_nofid: qemu_iovec_destroy(&qiov_full); pdu_complete(pdu, err); } static void coroutine_fn v9fs_create(void *opaque) { int32_t fid; int err = 0; size_t offset = 7; V9fsFidState *fidp; V9fsQID qid; int32_t perm; int8_t mode; V9fsPath path; struct stat stbuf; V9fsString name; V9fsString extension; int iounit; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; v9fs_path_init(&path); v9fs_string_init(&name); v9fs_string_init(&extension); err = pdu_unmarshal(pdu, offset, "dsdbs", &fid, &name, &perm, &mode, &extension); if (err < 0) { goto out_nofid; } trace_v9fs_create(pdu->tag, pdu->id, fid, name.data, perm, mode); if (name_is_illegal(name.data)) { err = -ENOENT; goto out_nofid; } if (!strcmp(".", name.data) || !strcmp("..", name.data)) { err = -EEXIST; goto out_nofid; } fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -EINVAL; goto out_nofid; } if (fidp->fid_type != P9_FID_NONE) { err = -EINVAL; goto out; } if (perm & P9_STAT_MODE_DIR) { err = v9fs_co_mkdir(pdu, fidp, &name, perm & 0777, fidp->uid, -1, &stbuf); if (err < 0) { goto out; } err = v9fs_co_name_to_path(pdu, &fidp->path, name.data, &path); if (err < 0) { goto out; } v9fs_path_write_lock(s); v9fs_path_copy(&fidp->path, &path); v9fs_path_unlock(s); err = v9fs_co_opendir(pdu, fidp); if (err < 0) { goto out; } fidp->fid_type = P9_FID_DIR; } else if (perm & P9_STAT_MODE_SYMLINK) { err = v9fs_co_symlink(pdu, fidp, &name, extension.data, -1 , &stbuf); if (err < 0) { goto out; } err = v9fs_co_name_to_path(pdu, &fidp->path, name.data, &path); if (err < 0) { goto out; } v9fs_path_write_lock(s); v9fs_path_copy(&fidp->path, &path); v9fs_path_unlock(s); } else if (perm & P9_STAT_MODE_LINK) { int32_t ofid = atoi(extension.data); V9fsFidState *ofidp = get_fid(pdu, ofid); if (ofidp == NULL) { err = -EINVAL; goto out; } err = v9fs_co_link(pdu, ofidp, fidp, &name); put_fid(pdu, ofidp); if (err < 0) { goto out; } err = v9fs_co_name_to_path(pdu, &fidp->path, name.data, &path); if (err < 0) { fidp->fid_type = P9_FID_NONE; goto out; } v9fs_path_write_lock(s); v9fs_path_copy(&fidp->path, &path); v9fs_path_unlock(s); err = v9fs_co_lstat(pdu, &fidp->path, &stbuf); if (err < 0) { fidp->fid_type = P9_FID_NONE; goto out; } } else if (perm & P9_STAT_MODE_DEVICE) { char ctype; uint32_t major, minor; mode_t nmode = 0; if (sscanf(extension.data, "%c %u %u", &ctype, &major, &minor) != 3) { err = -errno; goto out; } switch (ctype) { case 'c': nmode = S_IFCHR; break; case 'b': nmode = S_IFBLK; break; default: err = -EIO; goto out; } nmode |= perm & 0777; err = v9fs_co_mknod(pdu, fidp, &name, fidp->uid, -1, makedev(major, minor), nmode, &stbuf); if (err < 0) { goto out; } err = v9fs_co_name_to_path(pdu, &fidp->path, name.data, &path); if (err < 0) { goto out; } v9fs_path_write_lock(s); v9fs_path_copy(&fidp->path, &path); v9fs_path_unlock(s); } else if (perm & P9_STAT_MODE_NAMED_PIPE) { err = v9fs_co_mknod(pdu, fidp, &name, fidp->uid, -1, 0, S_IFIFO | (perm & 0777), &stbuf); if (err < 0) { goto out; } err = v9fs_co_name_to_path(pdu, &fidp->path, name.data, &path); if (err < 0) { goto out; } v9fs_path_write_lock(s); v9fs_path_copy(&fidp->path, &path); v9fs_path_unlock(s); } else if (perm & P9_STAT_MODE_SOCKET) { err = v9fs_co_mknod(pdu, fidp, &name, fidp->uid, -1, 0, S_IFSOCK | (perm & 0777), &stbuf); if (err < 0) { goto out; } err = v9fs_co_name_to_path(pdu, &fidp->path, name.data, &path); if (err < 0) { goto out; } v9fs_path_write_lock(s); v9fs_path_copy(&fidp->path, &path); v9fs_path_unlock(s); } else { err = v9fs_co_open2(pdu, fidp, &name, -1, omode_to_uflags(mode) | O_CREAT, perm, &stbuf); if (err < 0) { goto out; } fidp->fid_type = P9_FID_FILE; fidp->open_flags = omode_to_uflags(mode); if (fidp->open_flags & O_EXCL) { /* * We let the host file system do O_EXCL check * We should not reclaim such fd */ fidp->flags |= FID_NON_RECLAIMABLE; } } iounit = get_iounit(pdu, &fidp->path); err = stat_to_qid(pdu, &stbuf, &qid); if (err < 0) { goto out; } err = pdu_marshal(pdu, offset, "Qd", &qid, iounit); if (err < 0) { goto out; } err += offset; trace_v9fs_create_return(pdu->tag, pdu->id, qid.type, qid.version, qid.path, iounit); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); v9fs_string_free(&name); v9fs_string_free(&extension); v9fs_path_free(&path); } static void coroutine_fn v9fs_symlink(void *opaque) { V9fsPDU *pdu = opaque; V9fsString name; V9fsString symname; V9fsFidState *dfidp; V9fsQID qid; struct stat stbuf; int32_t dfid; int err = 0; gid_t gid; size_t offset = 7; v9fs_string_init(&name); v9fs_string_init(&symname); err = pdu_unmarshal(pdu, offset, "dssd", &dfid, &name, &symname, &gid); if (err < 0) { goto out_nofid; } trace_v9fs_symlink(pdu->tag, pdu->id, dfid, name.data, symname.data, gid); if (name_is_illegal(name.data)) { err = -ENOENT; goto out_nofid; } if (!strcmp(".", name.data) || !strcmp("..", name.data)) { err = -EEXIST; goto out_nofid; } dfidp = get_fid(pdu, dfid); if (dfidp == NULL) { err = -EINVAL; goto out_nofid; } err = v9fs_co_symlink(pdu, dfidp, &name, symname.data, gid, &stbuf); if (err < 0) { goto out; } err = stat_to_qid(pdu, &stbuf, &qid); if (err < 0) { goto out; } err = pdu_marshal(pdu, offset, "Q", &qid); if (err < 0) { goto out; } err += offset; trace_v9fs_symlink_return(pdu->tag, pdu->id, qid.type, qid.version, qid.path); out: put_fid(pdu, dfidp); out_nofid: pdu_complete(pdu, err); v9fs_string_free(&name); v9fs_string_free(&symname); } static void coroutine_fn v9fs_flush(void *opaque) { ssize_t err; int16_t tag; size_t offset = 7; V9fsPDU *cancel_pdu = NULL; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; err = pdu_unmarshal(pdu, offset, "w", &tag); if (err < 0) { pdu_complete(pdu, err); return; } trace_v9fs_flush(pdu->tag, pdu->id, tag); if (pdu->tag == tag) { warn_report("the guest sent a self-referencing 9P flush request"); } else { QLIST_FOREACH(cancel_pdu, &s->active_list, next) { if (cancel_pdu->tag == tag) { break; } } } if (cancel_pdu) { cancel_pdu->cancelled = 1; /* * Wait for pdu to complete. */ qemu_co_queue_wait(&cancel_pdu->complete, NULL); if (!qemu_co_queue_next(&cancel_pdu->complete)) { cancel_pdu->cancelled = 0; pdu_free(cancel_pdu); } } pdu_complete(pdu, 7); } static void coroutine_fn v9fs_link(void *opaque) { V9fsPDU *pdu = opaque; int32_t dfid, oldfid; V9fsFidState *dfidp, *oldfidp; V9fsString name; size_t offset = 7; int err = 0; v9fs_string_init(&name); err = pdu_unmarshal(pdu, offset, "dds", &dfid, &oldfid, &name); if (err < 0) { goto out_nofid; } trace_v9fs_link(pdu->tag, pdu->id, dfid, oldfid, name.data); if (name_is_illegal(name.data)) { err = -ENOENT; goto out_nofid; } if (!strcmp(".", name.data) || !strcmp("..", name.data)) { err = -EEXIST; goto out_nofid; } dfidp = get_fid(pdu, dfid); if (dfidp == NULL) { err = -ENOENT; goto out_nofid; } oldfidp = get_fid(pdu, oldfid); if (oldfidp == NULL) { err = -ENOENT; goto out; } err = v9fs_co_link(pdu, oldfidp, dfidp, &name); if (!err) { err = offset; } put_fid(pdu, oldfidp); out: put_fid(pdu, dfidp); out_nofid: v9fs_string_free(&name); pdu_complete(pdu, err); } /* Only works with path name based fid */ static void coroutine_fn v9fs_remove(void *opaque) { int32_t fid; int err = 0; size_t offset = 7; V9fsFidState *fidp; V9fsPDU *pdu = opaque; err = pdu_unmarshal(pdu, offset, "d", &fid); if (err < 0) { goto out_nofid; } trace_v9fs_remove(pdu->tag, pdu->id, fid); fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -EINVAL; goto out_nofid; } /* if fs driver is not path based, return EOPNOTSUPP */ if (!(pdu->s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT)) { err = -EOPNOTSUPP; goto out_err; } /* * IF the file is unlinked, we cannot reopen * the file later. So don't reclaim fd */ err = v9fs_mark_fids_unreclaim(pdu, &fidp->path); if (err < 0) { goto out_err; } err = v9fs_co_remove(pdu, &fidp->path); if (!err) { err = offset; } out_err: /* For TREMOVE we need to clunk the fid even on failed remove */ clunk_fid(pdu->s, fidp->fid); put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); } static void coroutine_fn v9fs_unlinkat(void *opaque) { int err = 0; V9fsString name; int32_t dfid, flags, rflags = 0; size_t offset = 7; V9fsPath path; V9fsFidState *dfidp; V9fsPDU *pdu = opaque; v9fs_string_init(&name); err = pdu_unmarshal(pdu, offset, "dsd", &dfid, &name, &flags); if (err < 0) { goto out_nofid; } if (name_is_illegal(name.data)) { err = -ENOENT; goto out_nofid; } if (!strcmp(".", name.data)) { err = -EINVAL; goto out_nofid; } if (!strcmp("..", name.data)) { err = -ENOTEMPTY; goto out_nofid; } if (flags & ~P9_DOTL_AT_REMOVEDIR) { err = -EINVAL; goto out_nofid; } if (flags & P9_DOTL_AT_REMOVEDIR) { rflags |= AT_REMOVEDIR; } dfidp = get_fid(pdu, dfid); if (dfidp == NULL) { err = -EINVAL; goto out_nofid; } /* * IF the file is unlinked, we cannot reopen * the file later. So don't reclaim fd */ v9fs_path_init(&path); err = v9fs_co_name_to_path(pdu, &dfidp->path, name.data, &path); if (err < 0) { goto out_err; } err = v9fs_mark_fids_unreclaim(pdu, &path); if (err < 0) { goto out_err; } err = v9fs_co_unlinkat(pdu, &dfidp->path, &name, rflags); if (!err) { err = offset; } out_err: put_fid(pdu, dfidp); v9fs_path_free(&path); out_nofid: pdu_complete(pdu, err); v9fs_string_free(&name); } /* Only works with path name based fid */ static int coroutine_fn v9fs_complete_rename(V9fsPDU *pdu, V9fsFidState *fidp, int32_t newdirfid, V9fsString *name) { int err = 0; V9fsPath new_path; V9fsFidState *tfidp; V9fsState *s = pdu->s; V9fsFidState *dirfidp = NULL; GHashTableIter iter; gpointer fid; v9fs_path_init(&new_path); if (newdirfid != -1) { dirfidp = get_fid(pdu, newdirfid); if (dirfidp == NULL) { return -ENOENT; } if (fidp->fid_type != P9_FID_NONE) { err = -EINVAL; goto out; } err = v9fs_co_name_to_path(pdu, &dirfidp->path, name->data, &new_path); if (err < 0) { goto out; } } else { char *dir_name = g_path_get_dirname(fidp->path.data); V9fsPath dir_path; v9fs_path_init(&dir_path); v9fs_path_sprintf(&dir_path, "%s", dir_name); g_free(dir_name); err = v9fs_co_name_to_path(pdu, &dir_path, name->data, &new_path); v9fs_path_free(&dir_path); if (err < 0) { goto out; } } err = v9fs_co_rename(pdu, &fidp->path, &new_path); if (err < 0) { goto out; } /* * Fixup fid's pointing to the old name to * start pointing to the new name */ g_hash_table_iter_init(&iter, s->fids); while (g_hash_table_iter_next(&iter, &fid, (gpointer *) &tfidp)) { if (v9fs_path_is_ancestor(&fidp->path, &tfidp->path)) { /* replace the name */ v9fs_fix_path(&tfidp->path, &new_path, strlen(fidp->path.data)); } } out: if (dirfidp) { put_fid(pdu, dirfidp); } v9fs_path_free(&new_path); return err; } /* Only works with path name based fid */ static void coroutine_fn v9fs_rename(void *opaque) { int32_t fid; ssize_t err = 0; size_t offset = 7; V9fsString name; int32_t newdirfid; V9fsFidState *fidp; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; v9fs_string_init(&name); err = pdu_unmarshal(pdu, offset, "dds", &fid, &newdirfid, &name); if (err < 0) { goto out_nofid; } if (name_is_illegal(name.data)) { err = -ENOENT; goto out_nofid; } if (!strcmp(".", name.data) || !strcmp("..", name.data)) { err = -EISDIR; goto out_nofid; } fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -ENOENT; goto out_nofid; } if (fidp->fid_type != P9_FID_NONE) { err = -EINVAL; goto out; } /* if fs driver is not path based, return EOPNOTSUPP */ if (!(pdu->s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT)) { err = -EOPNOTSUPP; goto out; } v9fs_path_write_lock(s); err = v9fs_complete_rename(pdu, fidp, newdirfid, &name); v9fs_path_unlock(s); if (!err) { err = offset; } out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); v9fs_string_free(&name); } static int coroutine_fn v9fs_fix_fid_paths(V9fsPDU *pdu, V9fsPath *olddir, V9fsString *old_name, V9fsPath *newdir, V9fsString *new_name) { V9fsFidState *tfidp; V9fsPath oldpath, newpath; V9fsState *s = pdu->s; int err; GHashTableIter iter; gpointer fid; v9fs_path_init(&oldpath); v9fs_path_init(&newpath); err = v9fs_co_name_to_path(pdu, olddir, old_name->data, &oldpath); if (err < 0) { goto out; } err = v9fs_co_name_to_path(pdu, newdir, new_name->data, &newpath); if (err < 0) { goto out; } /* * Fixup fid's pointing to the old name to * start pointing to the new name */ g_hash_table_iter_init(&iter, s->fids); while (g_hash_table_iter_next(&iter, &fid, (gpointer *) &tfidp)) { if (v9fs_path_is_ancestor(&oldpath, &tfidp->path)) { /* replace the name */ v9fs_fix_path(&tfidp->path, &newpath, strlen(oldpath.data)); } } out: v9fs_path_free(&oldpath); v9fs_path_free(&newpath); return err; } static int coroutine_fn v9fs_complete_renameat(V9fsPDU *pdu, int32_t olddirfid, V9fsString *old_name, int32_t newdirfid, V9fsString *new_name) { int err = 0; V9fsState *s = pdu->s; V9fsFidState *newdirfidp = NULL, *olddirfidp = NULL; olddirfidp = get_fid(pdu, olddirfid); if (olddirfidp == NULL) { err = -ENOENT; goto out; } if (newdirfid != -1) { newdirfidp = get_fid(pdu, newdirfid); if (newdirfidp == NULL) { err = -ENOENT; goto out; } } else { newdirfidp = get_fid(pdu, olddirfid); } err = v9fs_co_renameat(pdu, &olddirfidp->path, old_name, &newdirfidp->path, new_name); if (err < 0) { goto out; } if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) { /* Only for path based fid we need to do the below fixup */ err = v9fs_fix_fid_paths(pdu, &olddirfidp->path, old_name, &newdirfidp->path, new_name); } out: if (olddirfidp) { put_fid(pdu, olddirfidp); } if (newdirfidp) { put_fid(pdu, newdirfidp); } return err; } static void coroutine_fn v9fs_renameat(void *opaque) { ssize_t err = 0; size_t offset = 7; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; int32_t olddirfid, newdirfid; V9fsString old_name, new_name; v9fs_string_init(&old_name); v9fs_string_init(&new_name); err = pdu_unmarshal(pdu, offset, "dsds", &olddirfid, &old_name, &newdirfid, &new_name); if (err < 0) { goto out_err; } if (name_is_illegal(old_name.data) || name_is_illegal(new_name.data)) { err = -ENOENT; goto out_err; } if (!strcmp(".", old_name.data) || !strcmp("..", old_name.data) || !strcmp(".", new_name.data) || !strcmp("..", new_name.data)) { err = -EISDIR; goto out_err; } v9fs_path_write_lock(s); err = v9fs_complete_renameat(pdu, olddirfid, &old_name, newdirfid, &new_name); v9fs_path_unlock(s); if (!err) { err = offset; } out_err: pdu_complete(pdu, err); v9fs_string_free(&old_name); v9fs_string_free(&new_name); } static void coroutine_fn v9fs_wstat(void *opaque) { int32_t fid; int err = 0; int16_t unused; V9fsStat v9stat; size_t offset = 7; struct stat stbuf; V9fsFidState *fidp; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; v9fs_stat_init(&v9stat); err = pdu_unmarshal(pdu, offset, "dwS", &fid, &unused, &v9stat); if (err < 0) { goto out_nofid; } trace_v9fs_wstat(pdu->tag, pdu->id, fid, v9stat.mode, v9stat.atime, v9stat.mtime); fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -EINVAL; goto out_nofid; } /* do we need to sync the file? */ if (donttouch_stat(&v9stat)) { err = v9fs_co_fsync(pdu, fidp, 0); goto out; } if (v9stat.mode != -1) { uint32_t v9_mode; err = v9fs_co_lstat(pdu, &fidp->path, &stbuf); if (err < 0) { goto out; } v9_mode = stat_to_v9mode(&stbuf); if ((v9stat.mode & P9_STAT_MODE_TYPE_BITS) != (v9_mode & P9_STAT_MODE_TYPE_BITS)) { /* Attempting to change the type */ err = -EIO; goto out; } err = v9fs_co_chmod(pdu, &fidp->path, v9mode_to_mode(v9stat.mode, &v9stat.extension)); if (err < 0) { goto out; } } if (v9stat.mtime != -1 || v9stat.atime != -1) { struct timespec times[2]; if (v9stat.atime != -1) { times[0].tv_sec = v9stat.atime; times[0].tv_nsec = 0; } else { times[0].tv_nsec = UTIME_OMIT; } if (v9stat.mtime != -1) { times[1].tv_sec = v9stat.mtime; times[1].tv_nsec = 0; } else { times[1].tv_nsec = UTIME_OMIT; } err = v9fs_co_utimensat(pdu, &fidp->path, times); if (err < 0) { goto out; } } if (v9stat.n_gid != -1 || v9stat.n_uid != -1) { err = v9fs_co_chown(pdu, &fidp->path, v9stat.n_uid, v9stat.n_gid); if (err < 0) { goto out; } } if (v9stat.name.size != 0) { v9fs_path_write_lock(s); err = v9fs_complete_rename(pdu, fidp, -1, &v9stat.name); v9fs_path_unlock(s); if (err < 0) { goto out; } } if (v9stat.length != -1) { err = v9fs_co_truncate(pdu, &fidp->path, v9stat.length); if (err < 0) { goto out; } } err = offset; out: put_fid(pdu, fidp); out_nofid: v9fs_stat_free(&v9stat); pdu_complete(pdu, err); } static int v9fs_fill_statfs(V9fsState *s, V9fsPDU *pdu, struct statfs *stbuf) { uint32_t f_type; uint32_t f_bsize; uint64_t f_blocks; uint64_t f_bfree; uint64_t f_bavail; uint64_t f_files; uint64_t f_ffree; uint64_t fsid_val; uint32_t f_namelen; size_t offset = 7; int32_t bsize_factor; /* * compute bsize factor based on host file system block size * and client msize */ bsize_factor = (s->msize - P9_IOHDRSZ) / stbuf->f_bsize; if (!bsize_factor) { bsize_factor = 1; } f_type = stbuf->f_type; f_bsize = stbuf->f_bsize; f_bsize *= bsize_factor; /* * f_bsize is adjusted(multiplied) by bsize factor, so we need to * adjust(divide) the number of blocks, free blocks and available * blocks by bsize factor */ f_blocks = stbuf->f_blocks / bsize_factor; f_bfree = stbuf->f_bfree / bsize_factor; f_bavail = stbuf->f_bavail / bsize_factor; f_files = stbuf->f_files; f_ffree = stbuf->f_ffree; #ifdef CONFIG_DARWIN fsid_val = (unsigned int)stbuf->f_fsid.val[0] | (unsigned long long)stbuf->f_fsid.val[1] << 32; f_namelen = NAME_MAX; #else fsid_val = (unsigned int) stbuf->f_fsid.__val[0] | (unsigned long long)stbuf->f_fsid.__val[1] << 32; f_namelen = stbuf->f_namelen; #endif return pdu_marshal(pdu, offset, "ddqqqqqqd", f_type, f_bsize, f_blocks, f_bfree, f_bavail, f_files, f_ffree, fsid_val, f_namelen); } static void coroutine_fn v9fs_statfs(void *opaque) { int32_t fid; ssize_t retval = 0; size_t offset = 7; V9fsFidState *fidp; struct statfs stbuf; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; retval = pdu_unmarshal(pdu, offset, "d", &fid); if (retval < 0) { goto out_nofid; } fidp = get_fid(pdu, fid); if (fidp == NULL) { retval = -ENOENT; goto out_nofid; } retval = v9fs_co_statfs(pdu, &fidp->path, &stbuf); if (retval < 0) { goto out; } retval = v9fs_fill_statfs(s, pdu, &stbuf); if (retval < 0) { goto out; } retval += offset; out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, retval); } static void coroutine_fn v9fs_mknod(void *opaque) { int mode; gid_t gid; int32_t fid; V9fsQID qid; int err = 0; int major, minor; size_t offset = 7; V9fsString name; struct stat stbuf; V9fsFidState *fidp; V9fsPDU *pdu = opaque; v9fs_string_init(&name); err = pdu_unmarshal(pdu, offset, "dsdddd", &fid, &name, &mode, &major, &minor, &gid); if (err < 0) { goto out_nofid; } trace_v9fs_mknod(pdu->tag, pdu->id, fid, mode, major, minor); if (name_is_illegal(name.data)) { err = -ENOENT; goto out_nofid; } if (!strcmp(".", name.data) || !strcmp("..", name.data)) { err = -EEXIST; goto out_nofid; } fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -ENOENT; goto out_nofid; } err = v9fs_co_mknod(pdu, fidp, &name, fidp->uid, gid, makedev(major, minor), mode, &stbuf); if (err < 0) { goto out; } err = stat_to_qid(pdu, &stbuf, &qid); if (err < 0) { goto out; } err = pdu_marshal(pdu, offset, "Q", &qid); if (err < 0) { goto out; } err += offset; trace_v9fs_mknod_return(pdu->tag, pdu->id, qid.type, qid.version, qid.path); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); v9fs_string_free(&name); } /* * Implement posix byte range locking code * Server side handling of locking code is very simple, because 9p server in * QEMU can handle only one client. And most of the lock handling * (like conflict, merging) etc is done by the VFS layer itself, so no need to * do any thing in * qemu 9p server side lock code path. * So when a TLOCK request comes, always return success */ static void coroutine_fn v9fs_lock(void *opaque) { V9fsFlock flock; size_t offset = 7; struct stat stbuf; V9fsFidState *fidp; int32_t fid, err = 0; V9fsPDU *pdu = opaque; v9fs_string_init(&flock.client_id); err = pdu_unmarshal(pdu, offset, "dbdqqds", &fid, &flock.type, &flock.flags, &flock.start, &flock.length, &flock.proc_id, &flock.client_id); if (err < 0) { goto out_nofid; } trace_v9fs_lock(pdu->tag, pdu->id, fid, flock.type, flock.start, flock.length); /* We support only block flag now (that too ignored currently) */ if (flock.flags & ~P9_LOCK_FLAGS_BLOCK) { err = -EINVAL; goto out_nofid; } fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -ENOENT; goto out_nofid; } err = v9fs_co_fstat(pdu, fidp, &stbuf); if (err < 0) { goto out; } err = pdu_marshal(pdu, offset, "b", P9_LOCK_SUCCESS); if (err < 0) { goto out; } err += offset; trace_v9fs_lock_return(pdu->tag, pdu->id, P9_LOCK_SUCCESS); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); v9fs_string_free(&flock.client_id); } /* * When a TGETLOCK request comes, always return success because all lock * handling is done by client's VFS layer. */ static void coroutine_fn v9fs_getlock(void *opaque) { size_t offset = 7; struct stat stbuf; V9fsFidState *fidp; V9fsGetlock glock; int32_t fid, err = 0; V9fsPDU *pdu = opaque; v9fs_string_init(&glock.client_id); err = pdu_unmarshal(pdu, offset, "dbqqds", &fid, &glock.type, &glock.start, &glock.length, &glock.proc_id, &glock.client_id); if (err < 0) { goto out_nofid; } trace_v9fs_getlock(pdu->tag, pdu->id, fid, glock.type, glock.start, glock.length); fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -ENOENT; goto out_nofid; } err = v9fs_co_fstat(pdu, fidp, &stbuf); if (err < 0) { goto out; } glock.type = P9_LOCK_TYPE_UNLCK; err = pdu_marshal(pdu, offset, "bqqds", glock.type, glock.start, glock.length, glock.proc_id, &glock.client_id); if (err < 0) { goto out; } err += offset; trace_v9fs_getlock_return(pdu->tag, pdu->id, glock.type, glock.start, glock.length, glock.proc_id); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); v9fs_string_free(&glock.client_id); } static void coroutine_fn v9fs_mkdir(void *opaque) { V9fsPDU *pdu = opaque; size_t offset = 7; int32_t fid; struct stat stbuf; V9fsQID qid; V9fsString name; V9fsFidState *fidp; gid_t gid; int mode; int err = 0; v9fs_string_init(&name); err = pdu_unmarshal(pdu, offset, "dsdd", &fid, &name, &mode, &gid); if (err < 0) { goto out_nofid; } trace_v9fs_mkdir(pdu->tag, pdu->id, fid, name.data, mode, gid); if (name_is_illegal(name.data)) { err = -ENOENT; goto out_nofid; } if (!strcmp(".", name.data) || !strcmp("..", name.data)) { err = -EEXIST; goto out_nofid; } fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -ENOENT; goto out_nofid; } err = v9fs_co_mkdir(pdu, fidp, &name, mode, fidp->uid, gid, &stbuf); if (err < 0) { goto out; } err = stat_to_qid(pdu, &stbuf, &qid); if (err < 0) { goto out; } err = pdu_marshal(pdu, offset, "Q", &qid); if (err < 0) { goto out; } err += offset; trace_v9fs_mkdir_return(pdu->tag, pdu->id, qid.type, qid.version, qid.path, err); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); v9fs_string_free(&name); } static void coroutine_fn v9fs_xattrwalk(void *opaque) { int64_t size; V9fsString name; ssize_t err = 0; size_t offset = 7; int32_t fid, newfid; V9fsFidState *file_fidp; V9fsFidState *xattr_fidp = NULL; V9fsPDU *pdu = opaque; V9fsState *s = pdu->s; v9fs_string_init(&name); err = pdu_unmarshal(pdu, offset, "dds", &fid, &newfid, &name); if (err < 0) { goto out_nofid; } trace_v9fs_xattrwalk(pdu->tag, pdu->id, fid, newfid, name.data); file_fidp = get_fid(pdu, fid); if (file_fidp == NULL) { err = -ENOENT; goto out_nofid; } xattr_fidp = alloc_fid(s, newfid); if (xattr_fidp == NULL) { err = -EINVAL; goto out; } v9fs_path_copy(&xattr_fidp->path, &file_fidp->path); if (!v9fs_string_size(&name)) { /* * listxattr request. Get the size first */ size = v9fs_co_llistxattr(pdu, &xattr_fidp->path, NULL, 0); if (size < 0) { err = size; clunk_fid(s, xattr_fidp->fid); goto out; } /* * Read the xattr value */ xattr_fidp->fs.xattr.len = size; xattr_fidp->fid_type = P9_FID_XATTR; xattr_fidp->fs.xattr.xattrwalk_fid = true; xattr_fidp->fs.xattr.value = g_malloc0(size); if (size) { err = v9fs_co_llistxattr(pdu, &xattr_fidp->path, xattr_fidp->fs.xattr.value, xattr_fidp->fs.xattr.len); if (err < 0) { clunk_fid(s, xattr_fidp->fid); goto out; } } err = pdu_marshal(pdu, offset, "q", size); if (err < 0) { goto out; } err += offset; } else { /* * specific xattr fid. We check for xattr * presence also collect the xattr size */ size = v9fs_co_lgetxattr(pdu, &xattr_fidp->path, &name, NULL, 0); if (size < 0) { err = size; clunk_fid(s, xattr_fidp->fid); goto out; } /* * Read the xattr value */ xattr_fidp->fs.xattr.len = size; xattr_fidp->fid_type = P9_FID_XATTR; xattr_fidp->fs.xattr.xattrwalk_fid = true; xattr_fidp->fs.xattr.value = g_malloc0(size); if (size) { err = v9fs_co_lgetxattr(pdu, &xattr_fidp->path, &name, xattr_fidp->fs.xattr.value, xattr_fidp->fs.xattr.len); if (err < 0) { clunk_fid(s, xattr_fidp->fid); goto out; } } err = pdu_marshal(pdu, offset, "q", size); if (err < 0) { goto out; } err += offset; } trace_v9fs_xattrwalk_return(pdu->tag, pdu->id, size); out: put_fid(pdu, file_fidp); if (xattr_fidp) { put_fid(pdu, xattr_fidp); } out_nofid: pdu_complete(pdu, err); v9fs_string_free(&name); } #if defined(CONFIG_LINUX) /* Currently, only Linux has XATTR_SIZE_MAX */ #define P9_XATTR_SIZE_MAX XATTR_SIZE_MAX #elif defined(CONFIG_DARWIN) /* * Darwin doesn't seem to define a maximum xattr size in its user * space header, so manually configure it across platforms as 64k. * * Having no limit at all can lead to QEMU crashing during large g_malloc() * calls. Because QEMU does not currently support macOS guests, the below * preliminary solution only works due to its being a reflection of the limit of * Linux guests. */ #define P9_XATTR_SIZE_MAX 65536 #else #error Missing definition for P9_XATTR_SIZE_MAX for this host system #endif static void coroutine_fn v9fs_xattrcreate(void *opaque) { int flags, rflags = 0; int32_t fid; uint64_t size; ssize_t err = 0; V9fsString name; size_t offset = 7; V9fsFidState *file_fidp; V9fsFidState *xattr_fidp; V9fsPDU *pdu = opaque; v9fs_string_init(&name); err = pdu_unmarshal(pdu, offset, "dsqd", &fid, &name, &size, &flags); if (err < 0) { goto out_nofid; } trace_v9fs_xattrcreate(pdu->tag, pdu->id, fid, name.data, size, flags); if (flags & ~(P9_XATTR_CREATE | P9_XATTR_REPLACE)) { err = -EINVAL; goto out_nofid; } if (flags & P9_XATTR_CREATE) { rflags |= XATTR_CREATE; } if (flags & P9_XATTR_REPLACE) { rflags |= XATTR_REPLACE; } if (size > P9_XATTR_SIZE_MAX) { err = -E2BIG; goto out_nofid; } file_fidp = get_fid(pdu, fid); if (file_fidp == NULL) { err = -EINVAL; goto out_nofid; } if (file_fidp->fid_type != P9_FID_NONE) { err = -EINVAL; goto out_put_fid; } /* Make the file fid point to xattr */ xattr_fidp = file_fidp; xattr_fidp->fid_type = P9_FID_XATTR; xattr_fidp->fs.xattr.copied_len = 0; xattr_fidp->fs.xattr.xattrwalk_fid = false; xattr_fidp->fs.xattr.len = size; xattr_fidp->fs.xattr.flags = rflags; v9fs_string_init(&xattr_fidp->fs.xattr.name); v9fs_string_copy(&xattr_fidp->fs.xattr.name, &name); xattr_fidp->fs.xattr.value = g_malloc0(size); err = offset; out_put_fid: put_fid(pdu, file_fidp); out_nofid: pdu_complete(pdu, err); v9fs_string_free(&name); } static void coroutine_fn v9fs_readlink(void *opaque) { V9fsPDU *pdu = opaque; size_t offset = 7; V9fsString target; int32_t fid; int err = 0; V9fsFidState *fidp; err = pdu_unmarshal(pdu, offset, "d", &fid); if (err < 0) { goto out_nofid; } trace_v9fs_readlink(pdu->tag, pdu->id, fid); fidp = get_fid(pdu, fid); if (fidp == NULL) { err = -ENOENT; goto out_nofid; } v9fs_string_init(&target); err = v9fs_co_readlink(pdu, &fidp->path, &target); if (err < 0) { goto out; } err = pdu_marshal(pdu, offset, "s", &target); if (err < 0) { v9fs_string_free(&target); goto out; } err += offset; trace_v9fs_readlink_return(pdu->tag, pdu->id, target.data); v9fs_string_free(&target); out: put_fid(pdu, fidp); out_nofid: pdu_complete(pdu, err); } static CoroutineEntry *pdu_co_handlers[] = { [P9_TREADDIR] = v9fs_readdir, [P9_TSTATFS] = v9fs_statfs, [P9_TGETATTR] = v9fs_getattr, [P9_TSETATTR] = v9fs_setattr, [P9_TXATTRWALK] = v9fs_xattrwalk, [P9_TXATTRCREATE] = v9fs_xattrcreate, [P9_TMKNOD] = v9fs_mknod, [P9_TRENAME] = v9fs_rename, [P9_TLOCK] = v9fs_lock, [P9_TGETLOCK] = v9fs_getlock, [P9_TRENAMEAT] = v9fs_renameat, [P9_TREADLINK] = v9fs_readlink, [P9_TUNLINKAT] = v9fs_unlinkat, [P9_TMKDIR] = v9fs_mkdir, [P9_TVERSION] = v9fs_version, [P9_TLOPEN] = v9fs_open, [P9_TATTACH] = v9fs_attach, [P9_TSTAT] = v9fs_stat, [P9_TWALK] = v9fs_walk, [P9_TCLUNK] = v9fs_clunk, [P9_TFSYNC] = v9fs_fsync, [P9_TOPEN] = v9fs_open, [P9_TREAD] = v9fs_read, #if 0 [P9_TAUTH] = v9fs_auth, #endif [P9_TFLUSH] = v9fs_flush, [P9_TLINK] = v9fs_link, [P9_TSYMLINK] = v9fs_symlink, [P9_TCREATE] = v9fs_create, [P9_TLCREATE] = v9fs_lcreate, [P9_TWRITE] = v9fs_write, [P9_TWSTAT] = v9fs_wstat, [P9_TREMOVE] = v9fs_remove, }; static void coroutine_fn v9fs_op_not_supp(void *opaque) { V9fsPDU *pdu = opaque; pdu_complete(pdu, -EOPNOTSUPP); } static void coroutine_fn v9fs_fs_ro(void *opaque) { V9fsPDU *pdu = opaque; pdu_complete(pdu, -EROFS); } static inline bool is_read_only_op(V9fsPDU *pdu) { switch (pdu->id) { case P9_TREADDIR: case P9_TSTATFS: case P9_TGETATTR: case P9_TXATTRWALK: case P9_TLOCK: case P9_TGETLOCK: case P9_TREADLINK: case P9_TVERSION: case P9_TLOPEN: case P9_TATTACH: case P9_TSTAT: case P9_TWALK: case P9_TCLUNK: case P9_TFSYNC: case P9_TOPEN: case P9_TREAD: case P9_TAUTH: case P9_TFLUSH: return 1; default: return 0; } } void pdu_submit(V9fsPDU *pdu, P9MsgHeader *hdr) { Coroutine *co; CoroutineEntry *handler; V9fsState *s = pdu->s; pdu->size = le32_to_cpu(hdr->size_le); pdu->id = hdr->id; pdu->tag = le16_to_cpu(hdr->tag_le); if (pdu->id >= ARRAY_SIZE(pdu_co_handlers) || (pdu_co_handlers[pdu->id] == NULL)) { handler = v9fs_op_not_supp; } else if (is_ro_export(&s->ctx) && !is_read_only_op(pdu)) { handler = v9fs_fs_ro; } else { handler = pdu_co_handlers[pdu->id]; } qemu_co_queue_init(&pdu->complete); co = qemu_coroutine_create(handler, pdu); qemu_coroutine_enter(co); } /* Returns 0 on success, 1 on failure. */ int v9fs_device_realize_common(V9fsState *s, const V9fsTransport *t, Error **errp) { ERRP_GUARD(); int i, len; struct stat stat; FsDriverEntry *fse; V9fsPath path; int rc = 1; assert(!s->transport); s->transport = t; /* initialize pdu allocator */ QLIST_INIT(&s->free_list); QLIST_INIT(&s->active_list); for (i = 0; i < MAX_REQ; i++) { QLIST_INSERT_HEAD(&s->free_list, &s->pdus[i], next); s->pdus[i].s = s; s->pdus[i].idx = i; } v9fs_path_init(&path); fse = get_fsdev_fsentry(s->fsconf.fsdev_id); if (!fse) { /* We don't have a fsdev identified by fsdev_id */ error_setg(errp, "9pfs device couldn't find fsdev with the " "id = %s", s->fsconf.fsdev_id ? s->fsconf.fsdev_id : "NULL"); goto out; } if (!s->fsconf.tag) { /* we haven't specified a mount_tag */ error_setg(errp, "fsdev with id %s needs mount_tag arguments", s->fsconf.fsdev_id); goto out; } s->ctx.export_flags = fse->export_flags; s->ctx.fs_root = g_strdup(fse->path); s->ctx.exops.get_st_gen = NULL; len = strlen(s->fsconf.tag); if (len > MAX_TAG_LEN - 1) { error_setg(errp, "mount tag '%s' (%d bytes) is longer than " "maximum (%d bytes)", s->fsconf.tag, len, MAX_TAG_LEN - 1); goto out; } s->tag = g_strdup(s->fsconf.tag); s->ctx.uid = -1; s->ops = fse->ops; s->ctx.fmode = fse->fmode; s->ctx.dmode = fse->dmode; s->fids = g_hash_table_new(NULL, NULL); qemu_co_rwlock_init(&s->rename_lock); if (s->ops->init(&s->ctx, errp) < 0) { error_prepend(errp, "cannot initialize fsdev '%s': ", s->fsconf.fsdev_id); goto out; } /* * Check details of export path, We need to use fs driver * call back to do that. Since we are in the init path, we don't * use co-routines here. */ if (s->ops->name_to_path(&s->ctx, NULL, "/", &path) < 0) { error_setg(errp, "error in converting name to path %s", strerror(errno)); goto out; } if (s->ops->lstat(&s->ctx, &path, &stat)) { error_setg(errp, "share path %s does not exist", fse->path); goto out; } else if (!S_ISDIR(stat.st_mode)) { error_setg(errp, "share path %s is not a directory", fse->path); goto out; } s->dev_id = stat.st_dev; /* init inode remapping : */ /* hash table for variable length inode suffixes */ qpd_table_init(&s->qpd_table); /* hash table for slow/full inode remapping (most users won't need it) */ qpf_table_init(&s->qpf_table); /* hash table for quick inode remapping */ qpp_table_init(&s->qpp_table); s->qp_ndevices = 0; s->qp_affix_next = 1; /* reserve 0 to detect overflow */ s->qp_fullpath_next = 1; s->ctx.fst = &fse->fst; fsdev_throttle_init(s->ctx.fst); rc = 0; out: if (rc) { v9fs_device_unrealize_common(s); } v9fs_path_free(&path); return rc; } void v9fs_device_unrealize_common(V9fsState *s) { if (s->ops && s->ops->cleanup) { s->ops->cleanup(&s->ctx); } if (s->ctx.fst) { fsdev_throttle_cleanup(s->ctx.fst); } if (s->fids) { g_hash_table_destroy(s->fids); s->fids = NULL; } g_free(s->tag); qp_table_destroy(&s->qpd_table); qp_table_destroy(&s->qpp_table); qp_table_destroy(&s->qpf_table); g_free(s->ctx.fs_root); } typedef struct VirtfsCoResetData { V9fsPDU pdu; bool done; } VirtfsCoResetData; static void coroutine_fn virtfs_co_reset(void *opaque) { VirtfsCoResetData *data = opaque; virtfs_reset(&data->pdu); data->done = true; } void v9fs_reset(V9fsState *s) { VirtfsCoResetData data = { .pdu = { .s = s }, .done = false }; Coroutine *co; while (!QLIST_EMPTY(&s->active_list)) { aio_poll(qemu_get_aio_context(), true); } co = qemu_coroutine_create(virtfs_co_reset, &data); qemu_coroutine_enter(co); while (!data.done) { aio_poll(qemu_get_aio_context(), true); } } static void __attribute__((__constructor__)) v9fs_set_fd_limit(void) { struct rlimit rlim; if (getrlimit(RLIMIT_NOFILE, &rlim) < 0) { error_report("Failed to get the resource limit"); exit(1); } open_fd_hw = rlim.rlim_cur - MIN(400, rlim.rlim_cur / 3); open_fd_rc = rlim.rlim_cur / 2; }