blob: 9e046f7acb51cf718d453ac43ee7747ba61460f3 [file] [log] [blame]
/*
* Virtio 9p backend
*
* Copyright IBM, Corp. 2010
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include <glib/gprintf.h>
#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 "coth.h"
#include "trace.h"
#include "migration/blocker.h"
#include "sysemu/qtest.h"
#include "qemu/xxhash.h"
#include <math.h>
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,
};
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 },
{ P9_DOTL_DIRECT, O_DIRECT },
{ P9_DOTL_LARGEFILE, O_LARGEFILE },
{ P9_DOTL_DIRECTORY, O_DIRECTORY },
{ P9_DOTL_NOFOLLOW, O_NOFOLLOW },
{ P9_DOTL_NOATIME, O_NOATIME },
{ 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);
/*
* Ignore direct disk access hint until the server supports it.
*/
flags &= ~O_DIRECT;
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 GCC_FMT_ATTR(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;
for (f = s->fid_list; f; f = f->next) {
BUG_ON(f->clunked);
if (f->fid == fid) {
/*
* 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;
for (f = s->fid_list; f; f = f->next) {
/* If fid is already there return NULL */
BUG_ON(f->clunked);
if (f->fid == fid) {
return NULL;
}
}
f = g_malloc0(sizeof(V9fsFidState));
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;
f->next = s->fid_list;
s->fid_list = f;
v9fs_readdir_init(&f->fs.dir);
v9fs_readdir_init(&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 **fidpp, *fidp;
for (fidpp = &s->fid_list; *fidpp; fidpp = &(*fidpp)->next) {
if ((*fidpp)->fid == fid) {
break;
}
}
if (*fidpp == NULL) {
return NULL;
}
fidp = *fidpp;
*fidpp = fidp->next;
fidp->clunked = 1;
return fidp;
}
void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu)
{
int reclaim_count = 0;
V9fsState *s = pdu->s;
V9fsFidState *f, *reclaim_list = NULL;
for (f = s->fid_list; f; f = f->next) {
/*
* 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++;
f->rclm_lst = reclaim_list;
reclaim_list = f;
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++;
f->rclm_lst = reclaim_list;
reclaim_list = f;
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 (reclaim_list) {
f = reclaim_list;
reclaim_list = f->rclm_lst;
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);
}
f->rclm_lst = NULL;
/*
* Now drop the fid reference, free it
* if clunked.
*/
put_fid(pdu, f);
}
}
static int coroutine_fn v9fs_mark_fids_unreclaim(V9fsPDU *pdu, V9fsPath *path)
{
int err;
V9fsState *s = pdu->s;
V9fsFidState *fidp, head_fid;
head_fid.next = s->fid_list;
for (fidp = s->fid_list; fidp; fidp = fidp->next) {
if (fidp->path.size != path->size) {
continue;
}
if (!memcmp(fidp->path.data, path->data, path->size)) {
/* Mark the fid non reclaimable. */
fidp->flags |= FID_NON_RECLAIMABLE;
/* reopen the file/dir if already closed */
err = v9fs_reopen_fid(pdu, fidp);
if (err < 0) {
return err;
}
/*
* Go back to head of fid list because
* the list could have got updated when
* switched to the worker thread
*/
if (err == 0) {
fidp = &head_fid;
}
}
}
return 0;
}
static void coroutine_fn virtfs_reset(V9fsPDU *pdu)
{
V9fsState *s = pdu->s;
V9fsFidState *fidp;
/* Free all fids */
while (s->fid_list) {
/* Get fid */
fidp = s->fid_list;
fidp->ref++;
/* Clunk fid */
s->fid_list = fidp->next;
fidp->clunked = 1;
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));
}
/**
* @brief 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.
*
* @b 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
/**
* @brief Exponential Golomb algorithm for arbitrary k (including k=0).
*
* The Exponential Golomb algorithm generates @b prefixes (@b 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 (@param n) starts with 1, not with zero.
*
* @param n - natural number (or index) of the prefix to be generated
* (1, 2, 3, ...)
* @param k - parameter k of Exp. Golomb algorithm to be used
* (see comment on EXP_GOLOMB_K macro for details about k)
*/
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)
};
}
/**
* @brief Converts a suffix into a prefix, or a prefix into a suffix.
*
* 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
};
}
/**
* @brief Generates suffix numbers with "suffix-free" property.
*
* 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.
*
* @param n - natural number (or index) of the suffix to be generated
* (1, 2, 3, ...)
*/
static VariLenAffix affixForIndex(uint64_t index)
{
VariLenAffix prefix;
prefix = expGolombEncode(index, EXP_GOLOMB_K);
return invertAffix(&prefix); /* convert prefix to suffix */
}
/* creative abuse of tb_hash_func7, which is based on xxhash */
static uint32_t qpp_hash(QppEntry e)
{
return qemu_xxhash7(e.ino_prefix, e.dev, 0, 0, 0);
}
static uint32_t qpf_hash(QpfEntry e)
{
return qemu_xxhash7(e.ino, e.dev, 0, 0, 0);
}
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_malloc0(sizeof(QpdEntry));
*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;
}
/**
* @brief 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_malloc0(sizeof(QppEntry));
*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;
}
/**
* @brief 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_malloc0(sizeof(QppEntry));
*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;
}
static int coroutine_fn fid_to_qid(V9fsPDU *pdu, V9fsFidState *fidp,
V9fsQID *qidp)
{
struct stat stbuf;
int err;
err = v9fs_co_lstat(pdu, &fidp->path, &stbuf);
if (err < 0) {
return err;
}
err = stat_to_qid(pdu, &stbuf, qidp);
if (err < 0) {
return err;
}
return 0;
}
static int coroutine_fn dirent_to_qid(V9fsPDU *pdu, V9fsFidState *fidp,
struct dirent *dent, V9fsQID *qidp)
{
struct stat stbuf;
V9fsPath path;
int err;
v9fs_path_init(&path);
err = v9fs_co_name_to_path(pdu, &fidp->path, dent->d_name, &path);
if (err < 0) {
goto out;
}
err = v9fs_co_lstat(pdu, &path, &stbuf);
if (err < 0) {
goto out;
}
err = stat_to_qid(pdu, &stbuf, qidp);
out:
v9fs_path_free(&path);
return err;
}
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;
}
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 */
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 = stbuf->st_rdev;
v9lstat->st_size = stbuf->st_size;
v9lstat->st_blksize = stbuf->st_blksize;
v9lstat->st_blocks = stbuf->st_blocks;
v9lstat->st_atime_sec = stbuf->st_atime;
v9lstat->st_atime_nsec = stbuf->st_atim.tv_nsec;
v9lstat->st_mtime_sec = stbuf->st_mtime;
v9lstat->st_mtime_nsec = stbuf->st_mtim.tv_nsec;
v9lstat->st_ctime_sec = stbuf->st_ctime;
v9lstat->st_ctime_nsec = stbuf->st_ctim.tv_nsec;
/* 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;
}
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;
Error *local_err = NULL;
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 = fid_to_qid(pdu, fidp, &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, &local_err);
if (local_err) {
error_free(local_err);
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_qid, &qid, sizeof(qid));
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 not_same_qid(const V9fsQID *qid1, const V9fsQID *qid2)
{
return
qid1->type != qid2->type ||
qid1->version != qid2->version ||
qid1->path != qid2->path;
}
static void coroutine_fn v9fs_walk(void *opaque)
{
int name_idx;
V9fsQID *qids = NULL;
int i, err = 0;
V9fsPath dpath, path;
uint16_t nwnames;
struct stat stbuf;
size_t offset = 7;
int32_t fid, newfid;
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 && nwnames <= P9_MAXWELEM) {
wnames = g_new0(V9fsString, nwnames);
qids = g_new0(V9fsQID, 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;
}
} else if (nwnames > P9_MAXWELEM) {
err = -EINVAL;
goto out_nofid;
}
fidp = get_fid(pdu, fid);
if (fidp == NULL) {
err = -ENOENT;
goto out_nofid;
}
v9fs_path_init(&dpath);
v9fs_path_init(&path);
err = fid_to_qid(pdu, fidp, &qid);
if (err < 0) {
goto out;
}
/*
* Both dpath and path initially poin to fidp.
* Needed to handle request with nwnames == 0
*/
v9fs_path_copy(&dpath, &fidp->path);
v9fs_path_copy(&path, &fidp->path);
for (name_idx = 0; name_idx < nwnames; name_idx++) {
if (not_same_qid(&pdu->s->root_qid, &qid) ||
strcmp("..", wnames[name_idx].data)) {
err = v9fs_co_name_to_path(pdu, &dpath, wnames[name_idx].data,
&path);
if (err < 0) {
goto out;
}
err = v9fs_co_lstat(pdu, &path, &stbuf);
if (err < 0) {
goto out;
}
err = stat_to_qid(pdu, &stbuf, &qid);
if (err < 0) {
goto out;
}
v9fs_path_copy(&dpath, &path);
}
memcpy(&qids[name_idx], &qid, sizeof(qid));
}
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);
}
err = v9fs_walk_marshal(pdu, nwnames, qids);
trace_v9fs_walk_return(pdu->tag, pdu->id, nwnames, 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);
if (nwnames && nwnames <= P9_MAXWELEM) {
for (name_idx = 0; name_idx < nwnames; name_idx++) {
v9fs_string_free(&wnames[name_idx]);
}
g_free(wnames);
g_free(qids);
}
}
static int32_t coroutine_fn get_iounit(V9fsPDU *pdu, V9fsPath *path)
{
struct statfs stbuf;
int32_t iounit = 0;
V9fsState *s = pdu->s;
/*
* iounit should be multiples of f_bsize (host filesystem block size
* and as well as less than (client msize - P9_IOHDRSZ))
*/
if (!v9fs_co_statfs(pdu, path, &stbuf)) {
if (stbuf.f_bsize) {
iounit = stbuf.f_bsize;
iounit *= (s->msize - P9_IOHDRSZ) / stbuf.f_bsize;
}
}
if (!iounit) {
iounit = s->msize - P9_IOHDRSZ;
}
return iounit;
}
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;
size_t alloc_size = *size + skip;
if (is_write) {
pdu->s->transport->init_out_iov_from_pdu(pdu, &iov, &niov, alloc_size);
} else {
pdu->s->transport->init_in_iov_from_pdu(pdu, &iov, &niov, &alloc_size);
}
if (alloc_size < skip) {
*size = 0;
} else {
*size = alloc_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;
size_t read_count;
QEMUIOVector qiov_full;
if (fidp->fs.xattr.len < off) {
read_count = 0;
} else if (fidp->fs.xattr.len - off < max_count) {
read_count = fidp->fs.xattr.len - off;
} else {
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 = dent->d_off;
}
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 (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;
size_t size = max_count;
v9fs_init_qiov_from_pdu(&qiov_full, pdu, offset + 4, &size, false);
qemu_iovec_init(&qiov, qiov_full.niov);
max_count = size;
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);
}
static size_t v9fs_readdir_data_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 int coroutine_fn v9fs_do_readdir(V9fsPDU *pdu, V9fsFidState *fidp,
int32_t max_count)
{
size_t size;
V9fsQID qid;
V9fsString name;
int len, err = 0;
int32_t count = 0;
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_readdir_lock(&fidp->fs.dir);
err = v9fs_co_readdir(pdu, fidp, &dent);
if (err || !dent) {
break;
}
v9fs_string_init(&name);
v9fs_string_sprintf(&name, "%s", dent->d_name);
if ((count + v9fs_readdir_data_size(&name)) > 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_string_free(&name);
return count;
}
if (pdu->s->ctx.export_flags & V9FS_REMAP_INODES) {
/*
* dirent_to_qid() implies expensive stat call for each entry,
* we must do that here though since inode remapping requires
* the device id, which in turn might be different for
* different entries; we cannot make any assumption to avoid
* that here.
*/
err = dirent_to_qid(pdu, fidp, dent, &qid);
if (err < 0) {
v9fs_readdir_unlock(&fidp->fs.dir);
v9fs_co_seekdir(pdu, fidp, saved_dir_pos);
v9fs_string_free(&name);
return err;
}
} 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 dirent_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;
}
/* 11 = 7 + 4 (7 = start offset, 4 = space for storing count) */
len = pdu_marshal(pdu, 11 + count, "Qqbs",
&qid, dent->d_off,
dent->d_type, &name);
v9fs_readdir_unlock(&fidp->fs.dir);
if (len < 0) {
v9fs_co_seekdir(pdu, fidp, saved_dir_pos);
v9fs_string_free(&name);
return len;
}
count += len;
v9fs_string_free(&name);
saved_dir_pos = dent->d_off;
}
v9fs_readdir_unlock(&fidp->fs.dir);
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 (initial_offset == 0) {
v9fs_co_rewinddir(pdu, fidp);
} else {
v9fs_co_seekdir(pdu, fidp, initial_offset);
}
count = v9fs_do_readdir(pdu, fidp, 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;
size_t size;
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;
size = count;
v9fs_init_qiov_from_pdu(&qiov_full, pdu, offset, &size, true);
count = size;
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 (