Changeset c577a9a in mainline for uspace/srv/vfs/vfs_ops.c

Timestamp:

2017-03-05T20:23:05Z (8 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

354b642

Parents:

1dff985

git-author:

Jiri Zarevucky <zarevucky.jiri@…> (2017-03-05 20:23:05)

git-committer:

Jakub Jermar <jakub@…> (2017-03-05 20:23:05)

Message:

Merge from lp:~zarevucky-jiri/helenos/vfs-2.5 revisions 1929-1930

File:

• uspace/srv/vfs/vfs_ops.c (modified) (25 diffs)

uspace/srv/vfs/vfs_ops.c

@@ -500 +500 @@
         vfs_node_t *node = vfs_node_get(&lr);
         
-        int fd = vfs_fd_alloc(false);
+        vfs_file_t *file;
+        int fd = vfs_fd_alloc(&file, false);
         if (fd < 0) {
                 vfs_node_put(node);
@@ -509 +510 @@
                 return;
         }
-        
-        vfs_file_t *file = vfs_file_get(fd);
         assert(file != NULL);
         
@@ -598 +597 @@
          * the same open file at a time.
          */
-        fibril_mutex_lock(&file->lock);
         async_exch_t *fs_exch = vfs_exchange_grab(file->node->fs_handle);
         
@@ -612 +610 @@
         sysarg_t rc;
         async_wait_for(msg, &rc);
-        
-        fibril_mutex_unlock(&file->lock);
         
         vfs_file_put(file);
@@ -702 +698 @@
                 return ENOENT;
         
-        /*
-         * Lock the open file structure so that no other thread can manipulate
-         * the same open file at a time.
-         */
-        fibril_mutex_lock(&file->lock);
-        
         if ((read && !file->open_read) || (!read && !file->open_write)) {
-                fibril_mutex_unlock(&file->lock);
+                vfs_file_put(file);
                 return EINVAL;
         }
@@ -770 +760 @@
         if (rc == EOK)
                 file->pos += bytes;
-        fibril_mutex_unlock(&file->lock);
         vfs_file_put(file);     
 
@@ -812 +801 @@
                 return;
         }
-        
-        fibril_mutex_lock(&file->lock);
         
         off64_t newoff;
@@ -820 +807 @@
                 if (off >= 0) {
                         file->pos = (aoff64_t) off;
-                        fibril_mutex_unlock(&file->lock);
                         vfs_file_put(file);
                         async_answer_1(rid, EOK, off);
@@ -828 +814 @@
         case SEEK_CUR:
                 if ((off >= 0) && (file->pos + off < file->pos)) {
-                        fibril_mutex_unlock(&file->lock);
                         vfs_file_put(file);
                         async_answer_0(rid, EOVERFLOW);
@@ -835 +820 @@
                 
                 if ((off < 0) && (file->pos < (aoff64_t) -off)) {
-                        fibril_mutex_unlock(&file->lock);
                         vfs_file_put(file);
                         async_answer_0(rid, EOVERFLOW);
@@ -844 +828 @@
                 newoff = (file->pos > OFF64_MAX) ? OFF64_MAX : file->pos;
                 
-                fibril_mutex_unlock(&file->lock);
                 vfs_file_put(file);
                 async_answer_2(rid, EOK, LOWER32(newoff),
@@ -855 +838 @@
                 if ((off >= 0) && (size + off < size)) {
                         fibril_rwlock_read_unlock(&file->node->contents_rwlock);
-                        fibril_mutex_unlock(&file->lock);
                         vfs_file_put(file);
                         async_answer_0(rid, EOVERFLOW);
@@ -863 +845 @@
                 if ((off < 0) && (size < (aoff64_t) -off)) {
                         fibril_rwlock_read_unlock(&file->node->contents_rwlock);
-                        fibril_mutex_unlock(&file->lock);
                         vfs_file_put(file);
                         async_answer_0(rid, EOVERFLOW);
@@ -873 +854 @@
                 
                 fibril_rwlock_read_unlock(&file->node->contents_rwlock);
-                fibril_mutex_unlock(&file->lock);
                 vfs_file_put(file);
                 async_answer_2(rid, EOK, LOWER32(newoff), UPPER32(newoff));
@@ -879 +859 @@
         }
         
-        fibril_mutex_unlock(&file->lock);
         vfs_file_put(file);
         async_answer_0(rid, EINVAL);
@@ -908 +887 @@
                 return;
         }
-        fibril_mutex_lock(&file->lock);
 
         fibril_rwlock_write_lock(&file->node->contents_rwlock);
@@ -917 +895 @@
         fibril_rwlock_write_unlock(&file->node->contents_rwlock);
 
-        fibril_mutex_unlock(&file->lock);
         vfs_file_put(file);
         async_answer_0(rid, (sysarg_t)rc);
@@ -932 +909 @@
                 return;
         }
+        assert(file->node);
 
         ipc_callid_t callid;
@@ -941 +919 @@
         }
 
-        fibril_mutex_lock(&file->lock);
-
         async_exch_t *exch = vfs_exchange_grab(file->node->fs_handle);
+        assert(exch);
         
         aid_t msg;
         msg = async_send_3(exch, VFS_OUT_STAT, file->node->service_id,
             file->node->index, true, NULL);
+        assert(msg);
         async_forward_fast(callid, exch, 0, 0, 0, IPC_FF_ROUTE_FROM_ME);
         
@@ -954 +932 @@
         async_wait_for(msg, &rc);
         
-        fibril_mutex_unlock(&file->lock);
         vfs_file_put(file);
         async_answer_0(rid, rc);
@@ -989 +966 @@
         int lflag = (wflag&WALK_DIRECTORY) ? L_DIRECTORY: 0;
 
-        if (parentfd >= 0) {
+        /* Files are retrieved in order of file descriptors, to prevent deadlock. */
+        if (parentfd >= 0 && parentfd < expectfd) {
                 parent = vfs_file_get(parentfd);
                 if (!parent) {
@@ -995 +973 @@
                         goto exit;
                 }
-                parent_node = parent->node;
         }
         
@@ -1004 +981 @@
                         goto exit;
                 }
-                
+        }
+        
+        if (parentfd >= 0 && parentfd >= expectfd) {
+                parent = vfs_file_get(parentfd);
+                if (!parent) {
+                        rc = ENOENT;
+                        goto exit;
+                }
+        }
+        
+        if (parent) {
+                parent_node = parent->node;
+        }
+        
+        if (expectfd >= 0) {
                 vfs_lookup_res_t lr;
                 rc = vfs_lookup_internal(parent_node, path, lflag, &lr);
@@ -1228 +1219 @@
         }
         
-        /*
-         * Lock the open file structure so that no other thread can manipulate
-         * the same open file at a time.
-         */
-        fibril_mutex_lock(&oldfile->lock);
-        
         /* Make sure newfd is closed. */
         (void) vfs_fd_free(newfd);
@@ -1239 +1224 @@
         /* Assign the old file to newfd. */
         int ret = vfs_fd_assign(oldfile, newfd);
-        fibril_mutex_unlock(&oldfile->lock);
         vfs_file_put(oldfile);