hw/9pfs: Add stat/readlink/statfs for proxy FS

Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
This commit is contained in:
M. Mohan Kumar 2011-12-14 13:58:45 +05:30 committed by Aneesh Kumar K.V
parent 39f8c32c3f
commit b178adc3e7
3 changed files with 414 additions and 8 deletions

View File

@ -25,6 +25,8 @@
#include <sys/fsuid.h>
#include <stdarg.h>
#include <stdbool.h>
#include <sys/vfs.h>
#include <sys/stat.h>
#include "qemu-common.h"
#include "virtio-9p-marshal.h"
#include "hw/9pfs/virtio-9p-proxy.h"
@ -285,6 +287,172 @@ static int setfsugid(int uid, int gid)
return 0;
}
/*
* send response in two parts
* 1) ProxyHeader
* 2) Response or error status
* This function should be called with marshaled response
* send_response constructs header part and error part only.
* send response sends {ProxyHeader,Response} if the request was success
* otherwise sends {ProxyHeader,error status}
*/
static int send_response(int sock, struct iovec *iovec, int size)
{
int retval;
ProxyHeader header;
/*
* If response size exceeds available iovec->iov_len,
* we return ENOBUFS
*/
if (size > PROXY_MAX_IO_SZ) {
size = -ENOBUFS;
}
if (size < 0) {
/*
* In case of error we would not have got the error encoded
* already so encode the error here.
*/
header.type = T_ERROR;
header.size = sizeof(size);
proxy_marshal(iovec, PROXY_HDR_SZ, "d", size);
} else {
header.type = T_SUCCESS;
header.size = size;
}
proxy_marshal(iovec, 0, "dd", header.type, header.size);
retval = socket_write(sock, iovec->iov_base, header.size + PROXY_HDR_SZ);
if (retval < 0) {
return retval;;
}
return 0;
}
static void stat_to_prstat(ProxyStat *pr_stat, struct stat *stat)
{
memset(pr_stat, 0, sizeof(*pr_stat));
pr_stat->st_dev = stat->st_dev;
pr_stat->st_ino = stat->st_ino;
pr_stat->st_nlink = stat->st_nlink;
pr_stat->st_mode = stat->st_mode;
pr_stat->st_uid = stat->st_uid;
pr_stat->st_gid = stat->st_gid;
pr_stat->st_rdev = stat->st_rdev;
pr_stat->st_size = stat->st_size;
pr_stat->st_blksize = stat->st_blksize;
pr_stat->st_blocks = stat->st_blocks;
pr_stat->st_atim_sec = stat->st_atim.tv_sec;
pr_stat->st_atim_nsec = stat->st_atim.tv_nsec;
pr_stat->st_mtim_sec = stat->st_mtim.tv_sec;
pr_stat->st_mtim_nsec = stat->st_mtim.tv_nsec;
pr_stat->st_ctim_sec = stat->st_ctim.tv_sec;
pr_stat->st_ctim_nsec = stat->st_ctim.tv_nsec;
}
static void statfs_to_prstatfs(ProxyStatFS *pr_stfs, struct statfs *stfs)
{
memset(pr_stfs, 0, sizeof(*pr_stfs));
pr_stfs->f_type = stfs->f_type;
pr_stfs->f_bsize = stfs->f_bsize;
pr_stfs->f_blocks = stfs->f_blocks;
pr_stfs->f_bfree = stfs->f_bfree;
pr_stfs->f_bavail = stfs->f_bavail;
pr_stfs->f_files = stfs->f_files;
pr_stfs->f_ffree = stfs->f_ffree;
pr_stfs->f_fsid[0] = stfs->f_fsid.__val[0];
pr_stfs->f_fsid[1] = stfs->f_fsid.__val[1];
pr_stfs->f_namelen = stfs->f_namelen;
pr_stfs->f_frsize = stfs->f_frsize;
}
/*
* Gets stat/statfs information and packs in out_iovec structure
* on success returns number of bytes packed in out_iovec struture
* otherwise returns -errno
*/
static int do_stat(int type, struct iovec *iovec, struct iovec *out_iovec)
{
int retval;
V9fsString path;
ProxyStat pr_stat;
ProxyStatFS pr_stfs;
struct stat st_buf;
struct statfs stfs_buf;
v9fs_string_init(&path);
retval = proxy_unmarshal(iovec, PROXY_HDR_SZ, "s", &path);
if (retval < 0) {
return retval;
}
switch (type) {
case T_LSTAT:
retval = lstat(path.data, &st_buf);
if (retval < 0) {
retval = -errno;
} else {
stat_to_prstat(&pr_stat, &st_buf);
retval = proxy_marshal(out_iovec, PROXY_HDR_SZ,
"qqqdddqqqqqqqqqq", pr_stat.st_dev,
pr_stat.st_ino, pr_stat.st_nlink,
pr_stat.st_mode, pr_stat.st_uid,
pr_stat.st_gid, pr_stat.st_rdev,
pr_stat.st_size, pr_stat.st_blksize,
pr_stat.st_blocks,
pr_stat.st_atim_sec, pr_stat.st_atim_nsec,
pr_stat.st_mtim_sec, pr_stat.st_mtim_nsec,
pr_stat.st_ctim_sec, pr_stat.st_ctim_nsec);
}
break;
case T_STATFS:
retval = statfs(path.data, &stfs_buf);
if (retval < 0) {
retval = -errno;
} else {
statfs_to_prstatfs(&pr_stfs, &stfs_buf);
retval = proxy_marshal(out_iovec, PROXY_HDR_SZ,
"qqqqqqqqqqq", pr_stfs.f_type,
pr_stfs.f_bsize, pr_stfs.f_blocks,
pr_stfs.f_bfree, pr_stfs.f_bavail,
pr_stfs.f_files, pr_stfs.f_ffree,
pr_stfs.f_fsid[0], pr_stfs.f_fsid[1],
pr_stfs.f_namelen, pr_stfs.f_frsize);
}
break;
}
v9fs_string_free(&path);
return retval;
}
static int do_readlink(struct iovec *iovec, struct iovec *out_iovec)
{
char *buffer;
int size, retval;
V9fsString target, path;
v9fs_string_init(&path);
retval = proxy_unmarshal(iovec, PROXY_HDR_SZ, "sd", &path, &size);
if (retval < 0) {
v9fs_string_free(&path);
return retval;
}
buffer = g_malloc(size);
v9fs_string_init(&target);
retval = readlink(path.data, buffer, size);
if (retval > 0) {
buffer[retval] = '\0';
v9fs_string_sprintf(&target, "%s", buffer);
retval = proxy_marshal(out_iovec, PROXY_HDR_SZ, "s", &target);
} else {
retval = -errno;
}
g_free(buffer);
v9fs_string_free(&target);
v9fs_string_free(&path);
return retval;
}
/*
* create other filesystem objects and send 0 on success
* return -errno on error
@ -435,6 +603,13 @@ static int process_reply(int sock, int type,
return -1;
}
break;
case T_LSTAT:
case T_STATFS:
case T_READLINK:
if (send_response(sock, out_iovec, retval) < 0) {
return -1;
}
break;
default:
return -1;
break;
@ -491,6 +666,13 @@ static int process_requests(int sock)
v9fs_string_free(&oldpath);
v9fs_string_free(&path);
break;
case T_LSTAT:
case T_STATFS:
retval = do_stat(header.type, &in_iovec, &out_iovec);
break;
case T_READLINK:
retval = do_readlink(&in_iovec, &out_iovec);
break;
default:
goto err_out;
break;

View File

@ -101,6 +101,148 @@ static ssize_t socket_read(int sockfd, void *buff, size_t size)
return total;
}
/* Converts proxy_statfs to VFS statfs structure */
static void prstatfs_to_statfs(struct statfs *stfs, ProxyStatFS *prstfs)
{
memset(stfs, 0, sizeof(*stfs));
stfs->f_type = prstfs->f_type;
stfs->f_bsize = prstfs->f_bsize;
stfs->f_blocks = prstfs->f_blocks;
stfs->f_bfree = prstfs->f_bfree;
stfs->f_bavail = prstfs->f_bavail;
stfs->f_files = prstfs->f_files;
stfs->f_ffree = prstfs->f_ffree;
stfs->f_fsid.__val[0] = prstfs->f_fsid[0] & 0xFFFFFFFFUL;
stfs->f_fsid.__val[1] = prstfs->f_fsid[1] >> 32 & 0xFFFFFFFFFUL;
stfs->f_namelen = prstfs->f_namelen;
stfs->f_frsize = prstfs->f_frsize;
}
/* Converts proxy_stat structure to VFS stat structure */
static void prstat_to_stat(struct stat *stbuf, ProxyStat *prstat)
{
memset(stbuf, 0, sizeof(*stbuf));
stbuf->st_dev = prstat->st_dev;
stbuf->st_ino = prstat->st_ino;
stbuf->st_nlink = prstat->st_nlink;
stbuf->st_mode = prstat->st_mode;
stbuf->st_uid = prstat->st_uid;
stbuf->st_gid = prstat->st_gid;
stbuf->st_rdev = prstat->st_rdev;
stbuf->st_size = prstat->st_size;
stbuf->st_blksize = prstat->st_blksize;
stbuf->st_blocks = prstat->st_blocks;
stbuf->st_atim.tv_sec = prstat->st_atim_sec;
stbuf->st_atim.tv_nsec = prstat->st_atim_nsec;
stbuf->st_mtime = prstat->st_mtim_sec;
stbuf->st_mtim.tv_nsec = prstat->st_mtim_nsec;
stbuf->st_ctime = prstat->st_ctim_sec;
stbuf->st_ctim.tv_nsec = prstat->st_ctim_nsec;
}
/*
* Response contains two parts
* {header, data}
* header.type == T_ERROR, data -> -errno
* header.type == T_SUCCESS, data -> response
* size of errno/response is given by header.size
* returns < 0, on transport error. response is
* valid only if status >= 0.
*/
static int v9fs_receive_response(V9fsProxy *proxy, int type,
int *status, void *response)
{
int retval;
ProxyHeader header;
struct iovec *reply = &proxy->in_iovec;
*status = 0;
reply->iov_len = 0;
retval = socket_read(proxy->sockfd, reply->iov_base, PROXY_HDR_SZ);
if (retval < 0) {
return retval;
}
reply->iov_len = PROXY_HDR_SZ;
proxy_unmarshal(reply, 0, "dd", &header.type, &header.size);
/*
* if response size > PROXY_MAX_IO_SZ, read the response but ignore it and
* return -ENOBUFS
*/
if (header.size > PROXY_MAX_IO_SZ) {
int count;
while (header.size > 0) {
count = MIN(PROXY_MAX_IO_SZ, header.size);
count = socket_read(proxy->sockfd, reply->iov_base, count);
if (count < 0) {
return count;
}
header.size -= count;
}
*status = -ENOBUFS;
return 0;
}
retval = socket_read(proxy->sockfd,
reply->iov_base + PROXY_HDR_SZ, header.size);
if (retval < 0) {
return retval;
}
reply->iov_len += header.size;
/* there was an error during processing request */
if (header.type == T_ERROR) {
int ret;
ret = proxy_unmarshal(reply, PROXY_HDR_SZ, "d", status);
if (ret < 0) {
*status = ret;
}
return 0;
}
switch (type) {
case T_LSTAT: {
ProxyStat prstat;
retval = proxy_unmarshal(reply, PROXY_HDR_SZ,
"qqqdddqqqqqqqqqq", &prstat.st_dev,
&prstat.st_ino, &prstat.st_nlink,
&prstat.st_mode, &prstat.st_uid,
&prstat.st_gid, &prstat.st_rdev,
&prstat.st_size, &prstat.st_blksize,
&prstat.st_blocks,
&prstat.st_atim_sec, &prstat.st_atim_nsec,
&prstat.st_mtim_sec, &prstat.st_mtim_nsec,
&prstat.st_ctim_sec, &prstat.st_ctim_nsec);
prstat_to_stat(response, &prstat);
break;
}
case T_STATFS: {
ProxyStatFS prstfs;
retval = proxy_unmarshal(reply, PROXY_HDR_SZ,
"qqqqqqqqqqq", &prstfs.f_type,
&prstfs.f_bsize, &prstfs.f_blocks,
&prstfs.f_bfree, &prstfs.f_bavail,
&prstfs.f_files, &prstfs.f_ffree,
&prstfs.f_fsid[0], &prstfs.f_fsid[1],
&prstfs.f_namelen, &prstfs.f_frsize);
prstatfs_to_statfs(response, &prstfs);
break;
}
case T_READLINK: {
V9fsString target;
v9fs_string_init(&target);
retval = proxy_unmarshal(reply, PROXY_HDR_SZ, "s", &target);
strcpy(response, target.data);
v9fs_string_free(&target);
break;
}
default:
return -1;
}
if (retval < 0) {
*status = retval;
}
return 0;
}
/*
* return < 0 on transport error.
* *status is valid only if return >= 0
@ -143,6 +285,7 @@ static int v9fs_request(V9fsProxy *proxy, int type,
{
dev_t rdev;
va_list ap;
int size = 0;
int retval = 0;
ProxyHeader header = { 0, 0};
int flags, mode, uid, gid;
@ -228,6 +371,31 @@ static int v9fs_request(V9fsProxy *proxy, int type,
header.type = T_LINK;
}
break;
case T_LSTAT:
path = va_arg(ap, V9fsString *);
retval = proxy_marshal(iovec, PROXY_HDR_SZ, "s", path);
if (retval > 0) {
header.size = retval;
header.type = T_LSTAT;
}
break;
case T_READLINK:
path = va_arg(ap, V9fsString *);
size = va_arg(ap, int);
retval = proxy_marshal(iovec, PROXY_HDR_SZ, "sd", path, size);
if (retval > 0) {
header.size = retval;
header.type = T_READLINK;
}
break;
case T_STATFS:
path = va_arg(ap, V9fsString *);
retval = proxy_marshal(iovec, PROXY_HDR_SZ, "s", path);
if (retval > 0) {
header.size = retval;
header.type = T_STATFS;
}
break;
default:
error_report("Invalid type %d\n", type);
retval = -EINVAL;
@ -267,6 +435,13 @@ static int v9fs_request(V9fsProxy *proxy, int type,
goto close_error;
}
break;
case T_LSTAT:
case T_READLINK:
case T_STATFS:
if (v9fs_receive_response(proxy, type, &retval, response) < 0) {
goto close_error;
}
break;
}
err_out:
@ -282,15 +457,26 @@ close_error:
static int proxy_lstat(FsContext *fs_ctx, V9fsPath *fs_path, struct stat *stbuf)
{
errno = EOPNOTSUPP;
return -1;
int retval;
retval = v9fs_request(fs_ctx->private, T_LSTAT, stbuf, "s", fs_path);
if (retval < 0) {
errno = -retval;
return -1;
}
return retval;
}
static ssize_t proxy_readlink(FsContext *fs_ctx, V9fsPath *fs_path,
char *buf, size_t bufsz)
{
errno = EOPNOTSUPP;
return -1;
int retval;
retval = v9fs_request(fs_ctx->private, T_READLINK, buf, "sd",
fs_path, bufsz);
if (retval < 0) {
errno = -retval;
return -1;
}
return strlen(buf);
}
static int proxy_close(FsContext *ctx, V9fsFidOpenState *fs)
@ -513,8 +699,7 @@ static int proxy_link(FsContext *ctx, V9fsPath *oldpath,
v9fs_string_init(&newpath);
v9fs_string_sprintf(&newpath, "%s/%s", dirpath->data, name);
retval = v9fs_request(ctx->private, T_LINK, NULL, "ss",
oldpath, &newpath);
retval = v9fs_request(ctx->private, T_LINK, NULL, "ss", oldpath, &newpath);
v9fs_string_free(&newpath);
if (retval < 0) {
errno = -retval;
@ -575,8 +760,13 @@ static int proxy_fsync(FsContext *ctx, int fid_type,
static int proxy_statfs(FsContext *s, V9fsPath *fs_path, struct statfs *stbuf)
{
errno = EOPNOTSUPP;
return -1;
int retval;
retval = v9fs_request(s->private, T_STATFS, stbuf, "s", fs_path);
if (retval < 0) {
errno = -retval;
return -1;
}
return retval;
}
static ssize_t proxy_lgetxattr(FsContext *ctx, V9fsPath *fs_path,

View File

@ -45,6 +45,40 @@ enum {
T_MKDIR,
T_SYMLINK,
T_LINK,
T_LSTAT,
T_READLINK,
T_STATFS,
};
typedef struct {
uint64_t st_dev;
uint64_t st_ino;
uint64_t st_nlink;
uint32_t st_mode;
uint32_t st_uid;
uint32_t st_gid;
uint64_t st_rdev;
uint64_t st_size;
uint64_t st_blksize;
uint64_t st_blocks;
uint64_t st_atim_sec;
uint64_t st_atim_nsec;
uint64_t st_mtim_sec;
uint64_t st_mtim_nsec;
uint64_t st_ctim_sec;
uint64_t st_ctim_nsec;
} ProxyStat;
typedef struct {
uint64_t f_type;
uint64_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 f_fsid[2];
uint64_t f_namelen;
uint64_t f_frsize;
} ProxyStatFS;
#endif