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 "qemu/osdep.h"
  16 #include "fsdev/qemu-fsdev.h"
  17 #include "qemu/thread.h"
  18 #include "qemu/coroutine.h"
  19 #include "coth.h"
  20
  21 int v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t st_mode,
  22                    V9fsStatDotl *v9stat)
  23 {
  24     int err = 0;
  25     V9fsState *s = pdu->s;
  26
  27     if (v9fs_request_cancelled(pdu)) {
  28         return -EINTR;
  29     }
  30     if (s->ctx.exops.get_st_gen) {
  31         v9fs_path_read_lock(s);
  32         v9fs_co_run_in_worker(
  33             {
  34                 err = s->ctx.exops.get_st_gen(&s->ctx, path, st_mode,
  35                                               &v9stat->st_gen);
  36                 if (err < 0) {
  37                     err = -errno;
  38                 }
  39             });
  40         v9fs_path_unlock(s);
  41     }
  42     return err;
  43 }
  44
  45 int v9fs_co_lstat(V9fsPDU *pdu, V9fsPath *path, struct stat *stbuf)
  46 {
  47     int err;
  48     V9fsState *s = pdu->s;
  49
  50     if (v9fs_request_cancelled(pdu)) {
  51         return -EINTR;
  52     }
  53     v9fs_path_read_lock(s);
  54     v9fs_co_run_in_worker(
  55         {
  56             err = s->ops->lstat(&s->ctx, path, stbuf);
  57             if (err < 0) {
  58                 err = -errno;
  59             }
  60         });
  61     v9fs_path_unlock(s);
  62     return err;
  63 }
  64
  65 int v9fs_co_fstat(V9fsPDU *pdu, V9fsFidState *fidp, struct stat *stbuf)
  66 {
  67     int err;
  68     V9fsState *s = pdu->s;
  69
  70     if (v9fs_request_cancelled(pdu)) {
  71         return -EINTR;
  72     }
  73     v9fs_co_run_in_worker(
  74         {
  75             err = s->ops->fstat(&s->ctx, fidp->fid_type, &fidp->fs, stbuf);
  76             if (err < 0) {
  77                 err = -errno;
  78             }
  79         });
  80     /*
  81      * Some FS driver (local:mapped-file) can't support fetching attributes
  82      * using file descriptor. Use Path name in that case.
  83      */
  84     if (err == -EOPNOTSUPP) {
  85         err = v9fs_co_lstat(pdu, &fidp->path, stbuf);
  86         if (err == -ENOENT) {
  87             /*
  88              * fstat on an unlinked file. Work with partial results
  89              * returned from s->ops->fstat
  90              */
  91             err = 0;
  92         }
  93     }
  94     return err;
  95 }
  96
  97 int v9fs_co_open(V9fsPDU *pdu, V9fsFidState *fidp, int flags)
  98 {
  99     int err;
 100     V9fsState *s = pdu->s;
 101
 102     if (v9fs_request_cancelled(pdu)) {
 103         return -EINTR;
 104     }
 105     v9fs_path_read_lock(s);
 106     v9fs_co_run_in_worker(
 107         {
 108             err = s->ops->open(&s->ctx, &fidp->path, flags, &fidp->fs);
 109             if (err == -1) {
 110                 err = -errno;
 111             } else {
 112                 err = 0;
 113             }
 114         });
 115     v9fs_path_unlock(s);
 116     if (!err) {
 117         total_open_fd++;
 118         if (total_open_fd > open_fd_hw) {
 119             v9fs_reclaim_fd(pdu);
 120         }
 121     }
 122     return err;
 123 }
 124
 125 int v9fs_co_open2(V9fsPDU *pdu, V9fsFidState *fidp, V9fsString *name, gid_t gid,
 126                   int flags, int mode, struct stat *stbuf)
 127 {
 128     int err;
 129     FsCred cred;
 130     V9fsPath path;
 131     V9fsState *s = pdu->s;
 132
 133     if (v9fs_request_cancelled(pdu)) {
 134         return -EINTR;
 135     }
 136     cred_init(&cred);
 137     cred.fc_mode = mode & 07777;
 138     cred.fc_uid = fidp->uid;
 139     cred.fc_gid = gid;
 140     /*
 141      * Hold the directory fid lock so that directory path name
 142      * don't change. Read lock is fine because this fid cannot
 143      * be used by any other operation.
 144      */
 145     v9fs_path_read_lock(s);
 146     v9fs_co_run_in_worker(
 147         {
 148             err = s->ops->open2(&s->ctx, &fidp->path,
 149                                 name->data, flags, &cred, &fidp->fs);
 150             if (err < 0) {
 151                 err = -errno;
 152             } else {
 153                 v9fs_path_init(&path);
 154                 err = v9fs_name_to_path(s, &fidp->path, name->data, &path);
 155                 if (!err) {
 156                     err = s->ops->lstat(&s->ctx, &path, stbuf);
 157                     if (err < 0) {
 158                         err = -errno;
 159                         s->ops->close(&s->ctx, &fidp->fs);
 160                     } else {
 161                         v9fs_path_copy(&fidp->path, &path);
 162                     }
 163                 } else {
 164                     s->ops->close(&s->ctx, &fidp->fs);
 165                 }
 166                 v9fs_path_free(&path);
 167             }
 168         });
 169     v9fs_path_unlock(s);
 170     if (!err) {
 171         total_open_fd++;
 172         if (total_open_fd > open_fd_hw) {
 173             v9fs_reclaim_fd(pdu);
 174         }
 175     }
 176     return err;
 177 }
 178
 179 int v9fs_co_close(V9fsPDU *pdu, V9fsFidOpenState *fs)
 180 {
 181     int err;
 182     V9fsState *s = pdu->s;
 183
 184     if (v9fs_request_cancelled(pdu)) {
 185         return -EINTR;
 186     }
 187     v9fs_co_run_in_worker(
 188         {
 189             err = s->ops->close(&s->ctx, fs);
 190             if (err < 0) {
 191                 err = -errno;
 192             }
 193         });
 194     if (!err) {
 195         total_open_fd--;
 196     }
 197     return err;
 198 }
 199
 200 int v9fs_co_fsync(V9fsPDU *pdu, V9fsFidState *fidp, int datasync)
 201 {
 202     int err;
 203     V9fsState *s = pdu->s;
 204
 205     if (v9fs_request_cancelled(pdu)) {
 206         return -EINTR;
 207     }
 208     v9fs_co_run_in_worker(
 209         {
 210             err = s->ops->fsync(&s->ctx, fidp->fid_type, &fidp->fs, datasync);
 211             if (err < 0) {
 212                 err = -errno;
 213             }
 214         });
 215     return err;
 216 }
 217
 218 int v9fs_co_link(V9fsPDU *pdu, V9fsFidState *oldfid,
 219                  V9fsFidState *newdirfid, V9fsString *name)
 220 {
 221     int err;
 222     V9fsState *s = pdu->s;
 223
 224     if (v9fs_request_cancelled(pdu)) {
 225         return -EINTR;
 226     }
 227     v9fs_path_read_lock(s);
 228     v9fs_co_run_in_worker(
 229         {
 230             err = s->ops->link(&s->ctx, &oldfid->path,
 231                                &newdirfid->path, name->data);
 232             if (err < 0) {
 233                 err = -errno;
 234             }
 235         });
 236     v9fs_path_unlock(s);
 237     return err;
 238 }
 239
 240 int v9fs_co_pwritev(V9fsPDU *pdu, V9fsFidState *fidp,
 241                     struct iovec *iov, int iovcnt, int64_t offset)
 242 {
 243     int err;
 244     V9fsState *s = pdu->s;
 245
 246     if (v9fs_request_cancelled(pdu)) {
 247         return -EINTR;
 248     }
 249     v9fs_co_run_in_worker(
 250         {
 251             err = s->ops->pwritev(&s->ctx, &fidp->fs, iov, iovcnt, offset);
 252             if (err < 0) {
 253                 err = -errno;
 254             }
 255         });
 256     return err;
 257 }
 258
 259 int v9fs_co_preadv(V9fsPDU *pdu, V9fsFidState *fidp,
 260                    struct iovec *iov, int iovcnt, int64_t offset)
 261 {
 262     int err;
 263     V9fsState *s = pdu->s;
 264
 265     if (v9fs_request_cancelled(pdu)) {
 266         return -EINTR;
 267     }
 268     v9fs_co_run_in_worker(
 269         {
 270             err = s->ops->preadv(&s->ctx, &fidp->fs, iov, iovcnt, offset);
 271             if (err < 0) {
 272                 err = -errno;
 273             }
 274         });
 275     return err;
 276 }