hw/9pfs/cofile.c

   1
   2 /*
   3  * Virtio 9p backend
   4  *
   5  * Copyright IBM, Corp. 2011
   6  *
   7  * Authors:
   8  *  Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2.  See
  11  * the COPYING file in the top-level directory.
  12  *
  13  */
  14
  15 #include "fsdev/qemu-fsdev.h"
  16 #include "qemu-thread.h"
  17 #include "qemu-coroutine.h"
  18 #include "virtio-9p-coth.h"
  19
  20 int v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t st_mode,
  21                    V9fsStatDotl *v9stat)
  22 {
  23     int err = 0;
  24     V9fsState *s = pdu->s;
  25
  26     if (v9fs_request_cancelled(pdu)) {
  27         return -EINTR;
  28     }
  29     if (s->ctx.exops.get_st_gen) {
  30         v9fs_path_read_lock(s);
  31         v9fs_co_run_in_worker(
  32             {
  33                 err = s->ctx.exops.get_st_gen(&s->ctx, path, st_mode,
  34                                               &v9stat->st_gen);
  35                 if (err < 0) {
  36                     err = -errno;
  37                 }
  38             });
  39         v9fs_path_unlock(s);
  40     }
  41     return err;
  42 }
  43
  44 int v9fs_co_lstat(V9fsPDU *pdu, V9fsPath *path, struct stat *stbuf)
  45 {
  46     int err;
  47     V9fsState *s = pdu->s;
  48
  49     if (v9fs_request_cancelled(pdu)) {
  50         return -EINTR;
  51     }
  52     v9fs_path_read_lock(s);
  53     v9fs_co_run_in_worker(
  54         {
  55             err = s->ops->lstat(&s->ctx, path, stbuf);
  56             if (err < 0) {
  57                 err = -errno;
  58             }
  59         });
  60     v9fs_path_unlock(s);
  61     return err;
  62 }
  63
  64 int v9fs_co_fstat(V9fsPDU *pdu, int fd, struct stat *stbuf)
  65 {
  66     int err;
  67     V9fsState *s = pdu->s;
  68
  69     if (v9fs_request_cancelled(pdu)) {
  70         return -EINTR;
  71     }
  72     v9fs_co_run_in_worker(
  73         {
  74             err = s->ops->fstat(&s->ctx, fd, stbuf);
  75             if (err < 0) {
  76                 err = -errno;
  77             }
  78         });
  79     return err;
  80 }
  81
  82 int v9fs_co_open(V9fsPDU *pdu, V9fsFidState *fidp, int flags)
  83 {
  84     int err;
  85     V9fsState *s = pdu->s;
  86
  87     if (v9fs_request_cancelled(pdu)) {
  88         return -EINTR;
  89     }
  90     v9fs_path_read_lock(s);
  91     v9fs_co_run_in_worker(
  92         {
  93             fidp->fs.fd = s->ops->open(&s->ctx, &fidp->path, flags);
  94             if (fidp->fs.fd == -1) {
  95                 err = -errno;
  96             } else {
  97                 err = 0;
  98             }
  99         });
 100     v9fs_path_unlock(s);
 101     if (!err) {
 102         total_open_fd++;
 103         if (total_open_fd > open_fd_hw) {
 104             v9fs_reclaim_fd(pdu);
 105         }
 106     }
 107     return err;
 108 }
 109
 110 int v9fs_co_open2(V9fsPDU *pdu, V9fsFidState *fidp, V9fsString *name, gid_t gid,
 111                   int flags, int mode, struct stat *stbuf)
 112 {
 113     int err;
 114     FsCred cred;
 115     V9fsPath path;
 116     V9fsState *s = pdu->s;
 117
 118     if (v9fs_request_cancelled(pdu)) {
 119         return -EINTR;
 120     }
 121     cred_init(&cred);
 122     cred.fc_mode = mode & 07777;
 123     cred.fc_uid = fidp->uid;
 124     cred.fc_gid = gid;
 125     /*
 126      * Hold the directory fid lock so that directory path name
 127      * don't change. Read lock is fine because this fid cannot
 128      * be used by any other operation.
 129      */
 130     v9fs_path_read_lock(s);
 131     v9fs_co_run_in_worker(
 132         {
 133             fidp->fs.fd = s->ops->open2(&s->ctx, &fidp->path,
 134                                         name->data, flags, &cred);
 135             if (fidp->fs.fd == -1) {
 136                 err = -errno;
 137             } else {
 138                 v9fs_path_init(&path);
 139                 err = v9fs_name_to_path(s, &fidp->path, name->data, &path);
 140                 if (!err) {
 141                     err = s->ops->lstat(&s->ctx, &path, stbuf);
 142                     if (err < 0) {
 143                         err = -errno;
 144                         s->ops->close(&s->ctx, fidp->fs.fd);
 145                     } else {
 146                         v9fs_path_copy(&fidp->path, &path);
 147                     }
 148                 } else {
 149                     s->ops->close(&s->ctx, fidp->fs.fd);
 150                 }
 151                 v9fs_path_free(&path);
 152             }
 153         });
 154     v9fs_path_unlock(s);
 155     if (!err) {
 156         total_open_fd++;
 157         if (total_open_fd > open_fd_hw) {
 158             v9fs_reclaim_fd(pdu);
 159         }
 160     }
 161     return err;
 162 }
 163
 164 int v9fs_co_close(V9fsPDU *pdu, int fd)
 165 {
 166     int err;
 167     V9fsState *s = pdu->s;
 168
 169     if (v9fs_request_cancelled(pdu)) {
 170         return -EINTR;
 171     }
 172     v9fs_co_run_in_worker(
 173         {
 174             err = s->ops->close(&s->ctx, fd);
 175             if (err < 0) {
 176                 err = -errno;
 177             }
 178         });
 179     if (!err) {
 180         total_open_fd--;
 181     }
 182     return err;
 183 }
 184
 185 int v9fs_co_fsync(V9fsPDU *pdu, V9fsFidState *fidp, int datasync)
 186 {
 187     int fd, err;
 188     V9fsState *s = pdu->s;
 189
 190     if (v9fs_request_cancelled(pdu)) {
 191         return -EINTR;
 192     }
 193     fd = fidp->fs.fd;
 194     v9fs_co_run_in_worker(
 195         {
 196             err = s->ops->fsync(&s->ctx, fd, datasync);
 197             if (err < 0) {
 198                 err = -errno;
 199             }
 200         });
 201     return err;
 202 }
 203
 204 int v9fs_co_link(V9fsPDU *pdu, V9fsFidState *oldfid,
 205                  V9fsFidState *newdirfid, V9fsString *name)
 206 {
 207     int err;
 208     V9fsState *s = pdu->s;
 209
 210     if (v9fs_request_cancelled(pdu)) {
 211         return -EINTR;
 212     }
 213     v9fs_path_read_lock(s);
 214     v9fs_co_run_in_worker(
 215         {
 216             err = s->ops->link(&s->ctx, &oldfid->path,
 217                                &newdirfid->path, name->data);
 218             if (err < 0) {
 219                 err = -errno;
 220             }
 221         });
 222     v9fs_path_unlock(s);
 223     return err;
 224 }
 225
 226 int v9fs_co_pwritev(V9fsPDU *pdu, V9fsFidState *fidp,
 227                     struct iovec *iov, int iovcnt, int64_t offset)
 228 {
 229     int fd, err;
 230     V9fsState *s = pdu->s;
 231
 232     if (v9fs_request_cancelled(pdu)) {
 233         return -EINTR;
 234     }
 235     fd = fidp->fs.fd;
 236     v9fs_co_run_in_worker(
 237         {
 238             err = s->ops->pwritev(&s->ctx, fd, iov, iovcnt, offset);
 239             if (err < 0) {
 240                 err = -errno;
 241             }
 242         });
 243     return err;
 244 }
 245
 246 int v9fs_co_preadv(V9fsPDU *pdu, V9fsFidState *fidp,
 247                    struct iovec *iov, int iovcnt, int64_t offset)
 248 {
 249     int fd, err;
 250     V9fsState *s = pdu->s;
 251
 252     if (v9fs_request_cancelled(pdu)) {
 253         return -EINTR;
 254     }
 255     fd = fidp->fs.fd;
 256     v9fs_co_run_in_worker(
 257         {
 258             err = s->ops->preadv(&s->ctx, fd, iov, iovcnt, offset);
 259             if (err < 0) {
 260                 err = -errno;
 261             }
 262         });
 263     return err;
 264 }