Changeset b38dfd8 in mainline

Timestamp:

2010-12-06T19:40:52Z (14 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

4006447

Parents:

bea023b9 (diff), c2f4b6b (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 from lp:~jakub/helenos/fs.

Location:

uspace

Files:

• lib/c/include/ipc/vfs.h (modified) (2 diffs)
• srv/fs/devfs/devfs.c (modified) (1 diff)
• srv/fs/fat/fat.c (modified) (1 diff)
• srv/fs/tmpfs/tmpfs.c (modified) (1 diff)
• srv/vfs/vfs.h (modified) (1 diff)
• srv/vfs/vfs_ops.c (modified) (3 diffs)
• srv/vfs/vfs_register.c (modified) (1 diff)

uspace/lib/c/include/ipc/vfs.h

@@ -36 +36 @@
 #define LIBC_IPC_VFS_H_
 
+#include <ipc/ipc.h>
 #include <sys/types.h>
-#include <ipc/ipc.h>
+#include <bool.h>
 
 #define FS_NAME_MAXLEN  20
@@ -55 +56 @@
         /** Unique identifier of the fs. */
         char name[FS_NAME_MAXLEN + 1];
+        bool concurrent_read_write;
+        bool write_retains_size;
 } vfs_info_t;
 

uspace/srv/fs/devfs/devfs.c

@@ -53 +53 @@
 static vfs_info_t devfs_vfs_info = {
         .name = NAME,
+        .concurrent_read_write = false,
+        .write_retains_size = false,
 };
 

uspace/srv/fs/fat/fat.c

@@ -52 +52 @@
 vfs_info_t fat_vfs_info = {
         .name = NAME,
+        .concurrent_read_write = false,
+        .write_retains_size = false,    
 };
 

uspace/srv/fs/tmpfs/tmpfs.c

@@ -57 +57 @@
 vfs_info_t tmpfs_vfs_info = {
         .name = NAME,
+        .concurrent_read_write = false,
+        .write_retains_size = false,
 };
 

uspace/srv/vfs/vfs.h

@@ -172 +172 @@
 
 extern fs_handle_t fs_name_to_handle(char *, bool);
+extern vfs_info_t *fs_handle_to_info(fs_handle_t);
 
 extern int vfs_lookup_internal(char *, int, vfs_lookup_res_t *,

uspace/srv/vfs/vfs_ops.c

@@ -781 +781 @@
 static void vfs_rdwr(ipc_callid_t rid, ipc_call_t *request, bool read)
 {
+        vfs_info_t *vi;
 
         /*
@@ -807 +808 @@
         fibril_mutex_lock(&file->lock);
 
+        vi = fs_handle_to_info(file->node->fs_handle);
+        assert(vi);
+
         /*
          * Lock the file's node so that no other client can read/write to it at
-         * the same time.
-         */
-        if (read)
+         * the same time unless the FS supports concurrent reads/writes and its
+         * write implementation does not modify the file size.
+         */
+        if (read || (vi->concurrent_read_write && vi->write_retains_size))
                 fibril_rwlock_read_lock(&file->node->contents_rwlock);
         else
@@ -857 +862 @@
         
         /* Unlock the VFS node. */
-        if (read)
+        if (read || (vi->concurrent_read_write && vi->write_retains_size))
                 fibril_rwlock_read_unlock(&file->node->contents_rwlock);
         else {

uspace/srv/vfs/vfs_register.c

@@ -333 +333 @@
 }
 
+/** Find the VFS info structure.
+ *
+ * @param handle        FS handle for which the VFS info structure is sought.
+ * @return              VFS info structure on success or NULL otherwise.
+ */
+vfs_info_t *fs_handle_to_info(fs_handle_t handle)
+{
+        vfs_info_t *info = NULL;
+        link_t *cur;
+
+        fibril_mutex_lock(&fs_head_lock);
+        for (cur = fs_head.next; cur != &fs_head; cur = cur->next) {
+                fs_info_t *fs = list_get_instance(cur, fs_info_t, fs_link);
+                if (fs->fs_handle == handle) { 
+                        info = &fs->vfs_info;
+                        break;
+                }
+        }
+        fibril_mutex_unlock(&fs_head_lock);
+
+        return info;
+}
+
 /**
  * @}