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fc78d5ee76
qemu-e2k/hw/9pfs/9p.c
Keno Fischer fc78d5ee76 9pfs: Correctly handle cancelled requests 
# Background

I was investigating spurious non-deterministic EINTR returns from
various 9p file system operations in a Linux guest served from the
qemu 9p server.

 ## EINTR, ERESTARTSYS and the linux kernel

When a signal arrives that the Linux kernel needs to deliver to user-space
while a given thread is blocked (in the 9p case waiting for a reply to its
request in 9p_client_rpc -> wait_event_interruptible), it asks whatever
driver is currently running to abort its current operation (in the 9p case
causing the submission of a TFLUSH message) and return to user space.
In these situations, the error message reported is generally ERESTARTSYS.
If the userspace processes specified SA_RESTART, this means that the
system call will get restarted upon completion of the signal handler
delivery (assuming the signal handler doesn't modify the process state
in complicated ways not relevant here). If SA_RESTART is not specified,
ERESTARTSYS gets translated to EINTR and user space is expected to handle
the restart itself.

 ## The 9p TFLUSH command

The 9p TFLUSH commands requests that the server abort an ongoing operation.
The man page [1] specifies:

```
If it recognizes oldtag as the tag of a pending transaction, it should
abort any pending response and discard that tag.
[...]
When the client sends a Tflush, it must wait to receive the corresponding
Rflush before reusing oldtag for subsequent messages. If a response to the
flushed request is received before the Rflush, the client must honor the
response as if it had not been flushed, since the completed request may
signify a state change in the server
```

In particular, this means that the server must not send a reply with the
orignal tag in response to the cancellation request, because the client is
obligated to interpret such a reply as a coincidental reply to the original
request.

 # The bug

When qemu receives a TFlush request, it sets the `cancelled` flag on the
relevant pdu. This flag is periodically checked, e.g. in
`v9fs_co_name_to_path`, and if set, the operation is aborted and the error
is set to EINTR. However, the server then violates the spec, by returning
to the client an Rerror response, rather than discarding the message
entirely. As a result, the client is required to assume that said Rerror
response is a result of the original request, not a result of the
cancellation and thus passes the EINTR error back to user space.
This is not the worst thing it could do, however as discussed above, the
correct error code would have been ERESTARTSYS, such that user space
programs with SA_RESTART set get correctly restarted upon completion of
the signal handler.
Instead, such programs get spurious EINTR results that they were not
expecting to handle.

It should be noted that there are plenty of user space programs that do not
set SA_RESTART and do not correctly handle EINTR either. However, that is
then a userspace bug. It should also be noted that this bug has been
mitigated by a recent commit to the Linux kernel [2], which essentially
prevents the kernel from sending Tflush requests unless the process is about
to die (in which case the process likely doesn't care about the response).
Nevertheless, for older kernels and to comply with the spec, I believe this
change is beneficial.

 # Implementation

The fix is fairly simple, just skipping notification of a reply if
the pdu was previously cancelled. We do however, also notify the transport
layer that we're doing this, so it can clean up any resources it may be
holding. I also added a new trace event to distinguish
operations that caused an error reply from those that were cancelled.

One complication is that we only omit sending the message on EINTR errors in
order to avoid confusing the rest of the code (which may assume that a
client knows about a fid if it sucessfully passed it off to pud_complete
without checking for cancellation status). This does mean that if the server
acts upon the cancellation flag, it always needs to set err to EINTR. I
believe this is true of the current code.

[1] https://9fans.github.io/plan9port/man/man9/flush.html
[2] https://github.com/torvalds/linux/commit/9523feac272ccad2ad8186ba4fcc891

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
[groug, send a zero-sized reply instead of detaching the buffer]
Signed-off-by: Greg Kurz <groug@kaod.org>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2018-02-01 21:21:27 +01:00

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/*
* 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/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"
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 *lhs, V9fsPath *rhs)
{
v9fs_path_free(lhs);
lhs->data = g_malloc(rhs->size);
memcpy(lhs->data, rhs->data, rhs->size);
lhs->size = rhs->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)
/* This is the algorithm from ufs in spfs */
static void stat_to_qid(const struct stat *stbuf, V9fsQID *qidp)
{
size_t size;
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;
}
}
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;
}
stat_to_qid(&stbuf, qidp);
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;
}
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 == -1 &&
stat->qid.version == -1 &&
stat->qid.path == -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));
stat_to_qid(stbuf, &v9stat->qid);
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 void stat_to_v9stat_dotl(V9fsState *s, 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;
stat_to_qid(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");
}
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;
V9fsState *s = pdu->s;
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;
}
stat_to_v9stat_dotl(s, &stbuf, &v9stat_dotl);
/* 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;
}
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;
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_malloc0(sizeof(wnames[0]) * nwnames);
qids = g_malloc0(sizeof(qids[0]) * 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;
}
stat_to_qid(&stbuf, &qid);
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_copy(&fidp->path, &path);
} 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)) {
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;
}
stat_to_qid(&stbuf, &qid);
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);
stat_to_qid(&stbuf, &qid);
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 = 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;
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);
}
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;
}
/*
* 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
*/
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;
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);
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) {
err = -ENOSPC;
goto out;
}
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;
}
out:
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;
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_copy(&fidp->path, &path);
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_copy(&fidp->path, &path);
} 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_copy(&fidp->path, &path);
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_copy(&fidp->path, &path);
} 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_copy(&fidp->path, &path);
} 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_copy(&fidp->path, &path);
} 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);
stat_to_qid(&stbuf, &qid);
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;
}
stat_to_qid(&stbuf, &qid);
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;
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;
}
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, flags);
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;
v9fs_path_init(&new_path);
if (newdirfid != -1) {
dirfidp = get_fid(pdu, newdirfid);
if (dirfidp == NULL) {
err = -ENOENT;
goto out_nofid;
}
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
*/
for (tfidp = s->fid_list; tfidp; tfidp = tfidp->next) {
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);
out_nofid:
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;
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
*/
for (tfidp = s->fid_list; tfidp; tfidp = tfidp->next) {
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;
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) {
err = v9fs_complete_rename(pdu, fidp, -1, &v9stat.name);
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;
fsid_val = (unsigned int) stbuf->f_fsid.__val[0] |
(unsigned long long)stbuf->f_fsid.__val[1] << 32;
f_namelen = stbuf->f_namelen;
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;
}
stat_to_qid(&stbuf, &qid);
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;
}
stat_to_qid(&stbuf, &qid);
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;
if (size) {
xattr_fidp->fs.xattr.value = g_malloc0(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;
if (size) {
xattr_fidp->fs.xattr.value = g_malloc0(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);
}
static void coroutine_fn v9fs_xattrcreate(void *opaque)
{
int flags;
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 (size > 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 = flags;
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)
{
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->fid_list = 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->ctx.fst = &fse->fst;
fsdev_throttle_init(s->ctx.fst);
v9fs_path_free(&path);
rc = 0;
out:
if (rc) {
if (s->ops && s->ops->cleanup && s->ctx.private) {
s->ops->cleanup(&s->ctx);
}
g_free(s->tag);
g_free(s->ctx.fs_root);
v9fs_path_free(&path);
}
return rc;
}
void v9fs_device_unrealize_common(V9fsState *s, Error **errp)
{
if (s->ops->cleanup) {
s->ops->cleanup(&s->ctx);
}
fsdev_throttle_cleanup(s->ctx.fst);
g_free(s->tag);
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;
}
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