Changeset ff381a7 in mainline for uspace/lib/c/generic/vfs/vfs.c

Timestamp:

2015-11-02T20:54:19Z (8 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

d8513177

Parents:

3feeab2 (diff), 5265eea4 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge mainline changes.

File:

• uspace/lib/c/generic/vfs/vfs.c (modified) (40 diffs)

uspace/lib/c/generic/vfs/vfs.c

@@ -75 +75 @@
         
         while (vfs_sess == NULL)
-                vfs_sess = service_connect_blocking(EXCHANGE_PARALLEL, SERVICE_VFS,
-                    0, 0);
+                vfs_sess = service_connect_blocking(SERVICE_VFS, INTERFACE_VFS,
+                    0);
         
         fibril_mutex_unlock(&vfs_mutex);
@@ -93 +93 @@
 }
 
-char *absolutize(const char *path, size_t *retlen)
+char *vfs_absolutize(const char *path, size_t *retlen)
 {
         char *ncwd_path;
@@ -101 +101 @@
         size_t size = str_size(path);
         if (*path != '/') {
-                if (!cwd_path) {
+                if (cwd_path == NULL) {
                         fibril_mutex_unlock(&cwd_mutex);
                         return NULL;
                 }
                 ncwd_path_nc = malloc(cwd_size + 1 + size + 1);
-                if (!ncwd_path_nc) {
+                if (ncwd_path_nc == NULL) {
                         fibril_mutex_unlock(&cwd_mutex);
                         return NULL;
@@ -115 +115 @@
         } else {
                 ncwd_path_nc = malloc(size + 1);
-                if (!ncwd_path_nc) {
+                if (ncwd_path_nc == NULL) {
                         fibril_mutex_unlock(&cwd_mutex);
                         return NULL;
@@ -123 +123 @@
         str_append(ncwd_path_nc, cwd_size + 1 + size + 1, path);
         ncwd_path = canonify(ncwd_path_nc, retlen);
-        if (!ncwd_path) {
+        if (ncwd_path == NULL) {
                 fibril_mutex_unlock(&cwd_mutex);
                 free(ncwd_path_nc);
@@ -135 +135 @@
         ncwd_path = str_dup(ncwd_path);
         free(ncwd_path_nc);
-        if (!ncwd_path) {
+        if (ncwd_path == NULL) {
                 fibril_mutex_unlock(&cwd_mutex);
                 return NULL;
@@ -143 +143 @@
 }
 
-int mount(const char *fs_name, const char *mp, const char *fqsn,
+int vfs_mount(const char *fs_name, const char *mp, const char *fqsn,
     const char *opts, unsigned int flags, unsigned int instance)
 {
@@ -171 +171 @@
         
         size_t mpa_size;
-        char *mpa = absolutize(mp, &mpa_size);
-        if (!mpa) {
+        char *mpa = vfs_absolutize(mp, &mpa_size);
+        if (mpa == NULL) {
                 if (null_id != -1)
                         loc_null_destroy(null_id);
@@ -255 +255 @@
 }
 
-int unmount(const char *mp)
+int vfs_unmount(const char *mp)
 {
         sysarg_t rc;
@@ -263 +263 @@
         char *mpa;
         
-        mpa = absolutize(mp, &mpa_size);
-        if (!mpa)
+        mpa = vfs_absolutize(mp, &mpa_size);
+        if (mpa == NULL)
                 return ENOMEM;
         
@@ -289 +289 @@
 }
 
-static int open_internal(const char *abs, size_t abs_size, int lflag, int oflag)
+/** Open file (internal).
+ *
+ * @param abs Absolute path to file
+ * @param abs_size Size of @a abs string
+ * @param lflag L_xxx flags
+ * @param oflag O_xxx flags
+ * @param fd Place to store new file descriptor
+ *
+ * @return EOK on success, non-zero error code on error
+ */
+static int open_internal(const char *abs, size_t abs_size, int lflag, int oflag,
+    int *fd)
 {
         async_exch_t *exch = vfs_exchange_begin();
@@ -315 +326 @@
             return (int) rc;
         
-        return (int) IPC_GET_ARG1(answer);
-}
-
+        *fd = (int) IPC_GET_ARG1(answer);
+        return EOK;
+}
+
+/** Open file.
+ *
+ * @param path File path
+ * @param oflag O_xxx flags
+ * @param mode File mode (only with O_CREAT)
+ *
+ * @return Nonnegative file descriptor on success. On error -1 is returned
+ *         and errno is set.
+ */
 int open(const char *path, int oflag, ...)
 {
         size_t abs_size;
-        char *abs = absolutize(path, &abs_size);
-        if (!abs)
-                return ENOMEM;
-        
-        int ret = open_internal(abs, abs_size, L_FILE, oflag);
+        char *abs = vfs_absolutize(path, &abs_size);
+        int fd = -1;
+        
+        if (abs == NULL) {
+                errno = ENOMEM;
+                return -1;
+        }
+        
+        int rc = open_internal(abs, abs_size, L_FILE, oflag, &fd);
         free(abs);
         
-        return ret;
-}
-
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
+        
+        return fd;
+}
+
+/** Close file.
+ *
+ * @param fildes File descriptor
+ * @return Zero on success. On error -1 is returned and errno is set.
+ */
 int close(int fildes)
 {
@@ -339 +374 @@
         vfs_exchange_end(exch);
         
-        return (int) rc;
-}
-
-ssize_t read(int fildes, void *buf, size_t nbyte)
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
+        
+        return 0;
+}
+
+/** Read bytes from file.
+ *
+ * Read up to @a nbyte bytes from file. The actual number of bytes read
+ * may be lower, but greater than zero if there are any bytes available.
+ * If there are no bytes available for reading, then the function will
+ * return success with zero bytes read.
+ *
+ * @param fildes File descriptor
+ * @param buf Buffer
+ * @param nbyte Maximum number of bytes to read
+ * @param nread Place to store actual number of bytes read (0 or more)
+ *
+ * @return EOK on success, non-zero error code on error.
+ */
+static int _read_short(int fildes, void *buf, size_t nbyte, ssize_t *nread)
 {
         sysarg_t rc;
@@ -357 +411 @@
         if (rc != EOK) {
                 vfs_exchange_end(exch);
-
+                
                 sysarg_t rc_orig;
                 async_wait_for(req, &rc_orig);
-
+                
                 if (rc_orig == EOK)
-                        return (ssize_t) rc;
+                        return rc;
                 else
-                        return (ssize_t) rc_orig;
-        }
+                        return rc_orig;
+        }
+        
         vfs_exchange_end(exch);
         async_wait_for(req, &rc);
-        if (rc == EOK)
-                return (ssize_t) IPC_GET_ARG1(answer);
-        else
+        
+        if (rc != EOK)
                 return rc;
-}
-
-ssize_t write(int fildes, const void *buf, size_t nbyte) 
+        
+        *nread = (ssize_t) IPC_GET_ARG1(answer);
+        return EOK;
+}
+
+/** Write bytes to file.
+ *
+ * Write up to @a nbyte bytes from file. The actual number of bytes written
+ * may be lower, but greater than zero.
+ *
+ * @param fildes File descriptor
+ * @param buf Buffer
+ * @param nbyte Maximum number of bytes to write
+ * @param nread Place to store actual number of bytes written (0 or more)
+ *
+ * @return EOK on success, non-zero error code on error.
+ */
+static int _write_short(int fildes, const void *buf, size_t nbyte,
+    ssize_t *nwritten)
 {
         sysarg_t rc;
@@ -389 +459 @@
         if (rc != EOK) {
                 vfs_exchange_end(exch);
-
+                
                 sysarg_t rc_orig;
                 async_wait_for(req, &rc_orig);
-
+                
                 if (rc_orig == EOK)
-                        return (ssize_t) rc;
+                        return rc;
                 else
-                        return (ssize_t) rc_orig;
-        }
+                        return rc_orig;
+        }
+        
         vfs_exchange_end(exch);
         async_wait_for(req, &rc);
-        if (rc == EOK)
-                return (ssize_t) IPC_GET_ARG1(answer);
-        else
-                return -1;
-}
-
-/** Read entire buffer.
- *
- * In face of short reads this function continues reading until either
- * the entire buffer is read or no more data is available (at end of file).
+        
+        if (rc != EOK)
+                return rc;
+        
+        *nwritten = (ssize_t) IPC_GET_ARG1(answer);
+        return EOK;
+}
+
+/** Read data.
+ *
+ * Read up to @a nbytes bytes from file if available. This function always reads
+ * all the available bytes up to @a nbytes.
  *
  * @param fildes        File descriptor
@@ -415 +488 @@
  * @param nbytes        Number of bytes to read
  *
- * @return              On success, positive number of bytes read.
- *                      On failure, negative error code from read().
- */
-ssize_t read_all(int fildes, void *buf, size_t nbyte)
+ * @return              On success, nonnegative number of bytes read.
+ *                      On failure, -1 and sets errno.
+ */
+ssize_t read(int fildes, void *buf, size_t nbyte)
 {
         ssize_t cnt = 0;
         size_t nread = 0;
         uint8_t *bp = (uint8_t *) buf;
-
+        int rc;
+        
         do {
                 bp += cnt;
                 nread += cnt;
-                cnt = read(fildes, bp, nbyte - nread);
-        } while (cnt > 0 && (nbyte - nread - cnt) > 0);
-
-        if (cnt < 0)
-                return cnt;
-
+                rc = _read_short(fildes, bp, nbyte - nread, &cnt);
+        } while (rc == EOK && cnt > 0 && (nbyte - nread - cnt) > 0);
+        
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
+        
         return nread + cnt;
 }
 
-/** Write entire buffer.
+/** Write data.
  *
  * This function fails if it cannot write exactly @a len bytes to the file.
@@ -444 +520 @@
  * @param nbytes        Number of bytes to write
  *
- * @return              EOK on error, return value from write() if writing
- *                      failed.
- */
-ssize_t write_all(int fildes, const void *buf, size_t nbyte)
+ * @return              On success, nonnegative number of bytes written.
+ *                      On failure, -1 and sets errno.
+ */
+ssize_t write(int fildes, const void *buf, size_t nbyte)
 {
         ssize_t cnt = 0;
         ssize_t nwritten = 0;
         const uint8_t *bp = (uint8_t *) buf;
+        int rc;
 
         do {
                 bp += cnt;
                 nwritten += cnt;
-                cnt = write(fildes, bp, nbyte - nwritten);
-        } while (cnt > 0 && ((ssize_t )nbyte - nwritten - cnt) > 0);
-
-        if (cnt < 0)
-                return cnt;
-
-        if ((ssize_t)nbyte - nwritten - cnt > 0)
-                return EIO;
+                rc = _write_short(fildes, bp, nbyte - nwritten, &cnt);
+        } while (rc == EOK && ((ssize_t )nbyte - nwritten - cnt) > 0);
+
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
 
         return nbyte;
 }
 
+/** Synchronize file.
+ *
+ * @param fildes File descriptor
+ * @return 0 on success. On error returns -1 and sets errno.
+ */
 int fsync(int fildes)
 {
@@ -474 +555 @@
         vfs_exchange_end(exch);
         
-        return (int) rc;
-}
-
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
+        
+        return 0;
+}
+
+/** Seek to a position.
+ *
+ * @param fildes File descriptor
+ * @param offset Offset
+ * @param whence SEEK_SET, SEEK_CUR or SEEK_END
+ *
+ * @return On success the nonnegative offset from start of file. On error
+ *         returns (off64_t)-1 and sets errno.
+ */
 off64_t lseek(int fildes, off64_t offset, int whence)
 {
@@ -489 +584 @@
         vfs_exchange_end(exch);
         
-        if (rc != EOK)
+        if (rc != EOK) {
+                errno = rc;
                 return (off64_t) -1;
+        }
         
         return (off64_t) MERGE_LOUP32(newoff_lo, newoff_hi);
 }
 
+/** Truncate file to a specified length.
+ *
+ * Truncate file so that its size is exactly @a length
+ *
+ * @param fildes File descriptor
+ * @param length Length
+ *
+ * @return 0 on success, -1 on error and sets errno.
+ */
 int ftruncate(int fildes, aoff64_t length)
 {
@@ -504 +610 @@
         vfs_exchange_end(exch);
         
-        return (int) rc;
-}
-
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
+        
+        return 0;
+}
+
+/** Get file status.
+ *
+ * @param fildes File descriptor
+ * @param stat Place to store file information
+ *
+ * @return 0 on success, -1 on error and sets errno.
+ */
 int fstat(int fildes, struct stat *stat)
 {
@@ -518 +636 @@
         if (rc != EOK) {
                 vfs_exchange_end(exch);
-
+                
                 sysarg_t rc_orig;
                 async_wait_for(req, &rc_orig);
-
-                if (rc_orig == EOK)
-                        return (ssize_t) rc;
-                else
-                        return (ssize_t) rc_orig;
-        }
+                
+                if (rc_orig != EOK)
+                        rc = rc_orig;
+                if (rc != EOK) {
+                        errno = rc;
+                        return -1;
+                }
+                
+                return 0;
+        }
+        
         vfs_exchange_end(exch);
         async_wait_for(req, &rc);
-
-        return rc;
-}
-
+        
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
+        
+        return 0;
+}
+
+/** Get file status.
+ *
+ * @param path Path to file
+ * @param stat Place to store file information
+ *
+ * @return 0 on success, -1 on error and sets errno.
+ */
 int stat(const char *path, struct stat *stat)
 {
@@ -540 +675 @@
         
         size_t pa_size;
-        char *pa = absolutize(path, &pa_size);
-        if (!pa)
-                return ENOMEM;
+        char *pa = vfs_absolutize(path, &pa_size);
+        if (pa == NULL) {
+                errno = ENOMEM;
+                return -1;
+        }
         
         async_exch_t *exch = vfs_exchange_begin();
@@ -552 +689 @@
                 free(pa);
                 async_wait_for(req, &rc_orig);
+                if (rc_orig != EOK)
+                        rc = rc_orig;
+                if (rc != EOK) {
+                        errno = rc;
+                        return -1;
+                }
+        }
+        rc = async_data_read_start(exch, stat, sizeof(struct stat));
+        if (rc != EOK) {
+                vfs_exchange_end(exch);
+                free(pa);
+                async_wait_for(req, &rc_orig);
+                if (rc_orig != EOK)
+                        rc = rc_orig;
+                if (rc != EOK) {
+                        errno = rc;
+                        return -1;
+                }
+        }
+        vfs_exchange_end(exch);
+        free(pa);
+        async_wait_for(req, &rc);
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
+        return 0;
+}
+
+/** Open directory.
+ *
+ * @param dirname Directory pathname
+ *
+ * @return Non-NULL pointer on success. On error returns @c NULL and sets errno.
+ */
+DIR *opendir(const char *dirname)
+{
+        DIR *dirp = malloc(sizeof(DIR));
+        int fd = -1;
+        
+        if (dirp == NULL) {
+                errno = ENOMEM;
+                return NULL;
+        }
+        
+        size_t abs_size;
+        char *abs = vfs_absolutize(dirname, &abs_size);
+        if (abs == NULL) {
+                free(dirp);
+                errno = ENOMEM;
+                return NULL;
+        }
+        
+        int rc = open_internal(abs, abs_size, L_DIRECTORY, 0, &fd);
+        free(abs);
+        
+        if (rc != EOK) {
+                free(dirp);
+                errno = rc;
+                return NULL;
+        }
+        
+        dirp->fd = fd;
+        return dirp;
+}
+
+/** Read directory entry.
+ *
+ * @param dirp Open directory
+ * @return Non-NULL pointer to directory entry on success. On error returns
+ *         @c NULL and sets errno.
+ */
+struct dirent *readdir(DIR *dirp)
+{
+        int rc;
+        ssize_t len;
+        
+        rc = _read_short(dirp->fd, &dirp->res.d_name[0], NAME_MAX + 1, &len);
+        if (rc != EOK) {
+                errno = rc;
+                return NULL;
+        }
+        
+        (void) len;
+        return &dirp->res;
+}
+
+/** Rewind directory position to the beginning.
+ *
+ * @param dirp Open directory
+ */
+void rewinddir(DIR *dirp)
+{
+        (void) lseek(dirp->fd, 0, SEEK_SET);
+}
+
+/** Close directory.
+ *
+ * @param dirp Open directory
+ * @return 0 on success. On error returns -1 and sets errno.
+ */
+int closedir(DIR *dirp)
+{
+        int rc;
+        
+        rc = close(dirp->fd);
+        free(dirp);
+
+        /* On error errno was set by close() */
+        return rc;
+}
+
+/** Create directory.
+ *
+ * @param path Path
+ * @param mode File mode
+ * @return 0 on success. On error returns -1 and sets errno.
+ */
+int mkdir(const char *path, mode_t mode)
+{
+        sysarg_t rc;
+        aid_t req;
+        
+        size_t pa_size;
+        char *pa = vfs_absolutize(path, &pa_size);
+        if (pa == NULL) {
+                errno = ENOMEM;
+                return -1;
+        }
+        
+        async_exch_t *exch = vfs_exchange_begin();
+        
+        req = async_send_1(exch, VFS_IN_MKDIR, mode, NULL);
+        rc = async_data_write_start(exch, pa, pa_size);
+        if (rc != EOK) {
+                vfs_exchange_end(exch);
+                free(pa);
+                
+                sysarg_t rc_orig;
+                async_wait_for(req, &rc_orig);
+                
+                if (rc_orig != EOK)
+                        rc = rc_orig;
+                
+                if (rc != EOK) {
+                        errno = rc;
+                        return -1;
+                }
+                
+                return 0;
+        }
+        
+        vfs_exchange_end(exch);
+        free(pa);
+        async_wait_for(req, &rc);
+        
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
+        
+        return 0;
+}
+
+/** Unlink a file or directory.
+ *
+ * @param path Path to file or empty directory
+ * @param lflag L_xxx flag (L_NONE, L_FILE or L_DIRECTORY)
+ * @return EOK on success, non-zero error code on error
+ */
+static int _unlink(const char *path, int lflag)
+{
+        sysarg_t rc;
+        aid_t req;
+        
+        size_t pa_size;
+        char *pa = vfs_absolutize(path, &pa_size);
+        if (pa == NULL)
+                return ENOMEM;
+        
+        async_exch_t *exch = vfs_exchange_begin();
+        
+        req = async_send_1(exch, VFS_IN_UNLINK, lflag, NULL);
+        rc = async_data_write_start(exch, pa, pa_size);
+        if (rc != EOK) {
+                vfs_exchange_end(exch);
+                free(pa);
+
+                sysarg_t rc_orig;
+                async_wait_for(req, &rc_orig);
+
                 if (rc_orig == EOK)
                         return (int) rc;
@@ -557 +885 @@
                         return (int) rc_orig;
         }
-        rc = async_data_read_start(exch, stat, sizeof(struct stat));
-        if (rc != EOK) {
-                vfs_exchange_end(exch);
-                free(pa);
-                async_wait_for(req, &rc_orig);
-                if (rc_orig == EOK)
-                        return (int) rc;
-                else
-                        return (int) rc_orig;
-        }
         vfs_exchange_end(exch);
         free(pa);
@@ -573 +891 @@
 }
 
-DIR *opendir(const char *dirname)
-{
-        DIR *dirp = malloc(sizeof(DIR));
-        if (!dirp)
-                return NULL;
-        
-        size_t abs_size;
-        char *abs = absolutize(dirname, &abs_size);
-        if (!abs) {
-                free(dirp);
-                return NULL;
-        }
-        
-        int ret = open_internal(abs, abs_size, L_DIRECTORY, 0);
-        free(abs);
-        
-        if (ret < 0) {
-                free(dirp);
-                return NULL;
-        }
-        
-        dirp->fd = ret;
-        return dirp;
-}
-
-struct dirent *readdir(DIR *dirp)
-{
-        ssize_t len = read(dirp->fd, &dirp->res.d_name[0], NAME_MAX + 1);
-        if (len <= 0)
-                return NULL;
-        return &dirp->res;
-}
-
-void rewinddir(DIR *dirp)
-{
-        (void) lseek(dirp->fd, 0, SEEK_SET);
-}
-
-int closedir(DIR *dirp)
-{
-        (void) close(dirp->fd);
-        free(dirp);
+/** Unlink file or directory.
+ *
+ * @param path Path
+ * @return EOk on success, error code on error
+ */
+int unlink(const char *path)
+{
+        int rc;
+
+        rc = _unlink(path, L_NONE);
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
+
         return 0;
 }
 
-int mkdir(const char *path, mode_t mode)
-{
-        sysarg_t rc;
-        aid_t req;
-        
-        size_t pa_size;
-        char *pa = absolutize(path, &pa_size);
-        if (!pa)
-                return ENOMEM;
-        
-        async_exch_t *exch = vfs_exchange_begin();
-        
-        req = async_send_1(exch, VFS_IN_MKDIR, mode, NULL);
-        rc = async_data_write_start(exch, pa, pa_size);
-        if (rc != EOK) {
-                vfs_exchange_end(exch);
-                free(pa);
-
-                sysarg_t rc_orig;
-                async_wait_for(req, &rc_orig);
-
-                if (rc_orig == EOK)
-                        return (int) rc;
-                else
-                        return (int) rc_orig;
-        }
-        vfs_exchange_end(exch);
-        free(pa);
-        async_wait_for(req, &rc);
-        return rc;
-}
-
-static int _unlink(const char *path, int lflag)
-{
-        sysarg_t rc;
-        aid_t req;
-        
-        size_t pa_size;
-        char *pa = absolutize(path, &pa_size);
-        if (!pa)
-                return ENOMEM;
-        
-        async_exch_t *exch = vfs_exchange_begin();
-        
-        req = async_send_1(exch, VFS_IN_UNLINK, lflag, NULL);
-        rc = async_data_write_start(exch, pa, pa_size);
-        if (rc != EOK) {
-                vfs_exchange_end(exch);
-                free(pa);
-
-                sysarg_t rc_orig;
-                async_wait_for(req, &rc_orig);
-
-                if (rc_orig == EOK)
-                        return (int) rc;
-                else
-                        return (int) rc_orig;
-        }
-        vfs_exchange_end(exch);
-        free(pa);
-        async_wait_for(req, &rc);
-        return rc;
-}
-
-int unlink(const char *path)
-{
-        return _unlink(path, L_NONE);
-}
-
+/** Remove empty directory.
+ *
+ * @param path Path
+ * @return 0 on success. On error returns -1 and sets errno.
+ */
 int rmdir(const char *path)
 {
-        return _unlink(path, L_DIRECTORY);
-}
-
+        int rc;
+
+        rc = _unlink(path, L_DIRECTORY);
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
+
+        return 0;
+}
+
+/** Rename directory entry.
+ *
+ * @param old Old name
+ * @param new New name
+ *
+ * @return 0 on success. On error returns -1 and sets errno.
+ */
 int rename(const char *old, const char *new)
 {
@@ -699 +941 @@
         
         size_t olda_size;
-        char *olda = absolutize(old, &olda_size);
-        if (!olda)
-                return ENOMEM;
+        char *olda = vfs_absolutize(old, &olda_size);
+        if (olda == NULL) {
+                errno = ENOMEM;
+                return -1;
+        }
 
         size_t newa_size;
-        char *newa = absolutize(new, &newa_size);
-        if (!newa) {
+        char *newa = vfs_absolutize(new, &newa_size);
+        if (newa == NULL) {
                 free(olda);
-                return ENOMEM;
+                errno = ENOMEM;
+                return -1;
         }
         
@@ -719 +964 @@
                 free(newa);
                 async_wait_for(req, &rc_orig);
-                if (rc_orig == EOK)
-                        return (int) rc;
-                else
-                        return (int) rc_orig;
+                if (rc_orig != EOK)
+                        rc = rc_orig;
+                if (rc != EOK) {
+                        errno = rc;
+                        return -1;
+                }
+                return 0;
         }
         rc = async_data_write_start(exch, newa, newa_size);
@@ -730 +978 @@
                 free(newa);
                 async_wait_for(req, &rc_orig);
-                if (rc_orig == EOK)
-                        return (int) rc;
-                else
-                        return (int) rc_orig;
+                if (rc_orig != EOK)
+                        rc = rc_orig;
+                if (rc != EOK) {
+                        errno = rc;
+                        return -1;
+                }
+                return 0;
         }
         vfs_exchange_end(exch);
@@ -739 +990 @@
         free(newa);
         async_wait_for(req, &rc);
-        return rc;
-}
-
+
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
+
+        return 0;
+}
+
+/** Remove directory entry.
+ *
+ * @param path Path
+ * @return 0 on success. On error returns -1 and sets errno.
+ */
 int remove(const char *path)
 {
@@ -747 +1009 @@
 }
 
+/** Change working directory.
+ *
+ * @param path Path
+ * @return 0 on success. On error returns -1 and sets errno.
+ */
 int chdir(const char *path)
 {
         size_t abs_size;
-        char *abs = absolutize(path, &abs_size);
-        if (!abs)
-                return ENOMEM;
-        
-        int fd = open_internal(abs, abs_size, L_DIRECTORY, O_DESC);
-        
-        if (fd < 0) {
+        char *abs = vfs_absolutize(path, &abs_size);
+        int fd = -1;
+        
+        if (abs == NULL) {
+                errno = ENOMEM;
+                return -1;
+        }
+        
+        int rc = open_internal(abs, abs_size, L_DIRECTORY, O_DESC, &fd);
+        
+        if (rc != EOK) {
                 free(abs);
-                return ENOENT;
+                errno = rc;
+                return -1;
         }
         
@@ -765 +1037 @@
         if (cwd_fd >= 0)
                 close(cwd_fd);
-        
         
         if (cwd_path)
@@ -775 +1046 @@
         
         fibril_mutex_unlock(&cwd_mutex);
-        return EOK;
-}
-
+        return 0;
+}
+
+/** Get current working directory path.
+ *
+ * @param buf Buffer
+ * @param size Size of @a buf
+ * @return On success returns @a buf. On failure returns @c NULL and sets errno.
+ */
 char *getcwd(char *buf, size_t size)
 {
-        if (size == 0)
+        if (size == 0) {
+                errno = EINVAL;
                 return NULL;
+        }
         
         fibril_mutex_lock(&cwd_mutex);
@@ -787 +1066 @@
         if ((cwd_size == 0) || (size < cwd_size + 1)) {
                 fibril_mutex_unlock(&cwd_mutex);
+                errno = ERANGE;
                 return NULL;
         }
@@ -796 +1076 @@
 }
 
-async_sess_t *fd_session(exch_mgmt_t mgmt, int fildes)
+/** Open session to service represented by a special file.
+ *
+ * Given that the file referred to by @a fildes represents a service,
+ * open a session to that service.
+ *
+ * @param fildes File descriptor
+ * @param iface Interface to connect to (XXX Should be automatic)
+ * @return On success returns session pointer. On error returns @c NULL.
+ */
+async_sess_t *vfs_fd_session(int fildes, iface_t iface)
 {
         struct stat stat;
         int rc = fstat(fildes, &stat);
-        if (rc != 0) {
-                errno = rc;
+        if (rc != 0)
                 return NULL;
-        }
-        
-        if (!stat.service) {
-                errno = ENOENT;
+        
+        if (stat.service == 0)
                 return NULL;
-        }
-        
-        return loc_service_connect(mgmt, stat.service, 0);
-}
-
+        
+        return loc_service_connect(stat.service, iface, 0);
+}
+
+/** Duplicate open file.
+ *
+ * Duplicate open file under a new file descriptor.
+ *
+ * @param oldfd Old file descriptor
+ * @param newfd New file descriptor
+ * @return 0 on success. On error -1 is returned and errno is set
+ */
 int dup2(int oldfd, int newfd)
 {
@@ -823 +1116 @@
         
         if (rc == EOK)
-                return (int) ret;
-        
-        return (int) rc;
-}
-
-int fd_wait(void)
+                rc = ret;
+        
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
+        
+        return 0;
+}
+
+int vfs_fd_wait(void)
 {
         async_exch_t *exch = vfs_exchange_begin();
@@ -843 +1141 @@
 }
 
-int get_mtab_list(list_t *mtab_list)
+int vfs_get_mtab_list(list_t *mtab_list)
 {
         sysarg_t rc;
@@ -863 +1161 @@
 
                 mtab_ent = malloc(sizeof(mtab_ent_t));
-                if (!mtab_ent) {
+                if (mtab_ent == NULL) {
                         rc = ENOMEM;
                         goto exit;
@@ -904 +1202 @@
 }
 
+/** Get filesystem statistics.
+ *
+ * @param path Mount point path
+ * @param st Buffer for storing information
+ * @return 0 on success. On error -1 is returned and errno is set.
+ */
 int statfs(const char *path, struct statfs *st)
 {
@@ -910 +1214 @@
         size_t pa_size;
 
-        char *pa = absolutize(path, &pa_size);
-        if (!pa)
-                return ENOMEM;
+        char *pa = vfs_absolutize(path, &pa_size);
+        if (pa == NULL) {
+                errno = ENOMEM;
+                return -1;
+        }
 
         async_exch_t *exch = vfs_exchange_begin();
@@ -927 +1233 @@
         free(pa);
         async_wait_for(req, &rc_orig);
-        return (int) (rc_orig != EOK ? rc_orig : rc);
+        rc = (rc_orig != EOK ? rc_orig : rc);
+
+        if (rc != EOK) {
+                errno = rc;
+                return -1;
+        }
+
+        return 0;
 }