[FIX][DFSv2][ELMFAT]修复多线程环境下lseek返回值概率性被篡改的问题

AngryProton · AngryProton · commit 83b28c3cca2b · 2025-12-24T22:52:04.000+08:00
diff --git a/components/dfs/dfs_v2/filesystems/elmfat/dfs_elm.c b/components/dfs/dfs_v2/filesystems/elmfat/dfs_elm.c
@@ -629,7 +629,7 @@ int dfs_elm_flush(struct dfs_file *file)
 off_t dfs_elm_lseek(struct dfs_file *file, off_t offset, int wherece)
 {
     FRESULT result = FR_OK;
-
+    off_t pos = 0;
     switch (wherece)
     {
     case SEEK_SET:
@@ -656,11 +656,12 @@ off_t dfs_elm_lseek(struct dfs_file *file, off_t offset, int wherece)
         RT_ASSERT(fd != RT_NULL);
         rt_mutex_take(&file->vnode->lock, RT_WAITING_FOREVER);
         result = f_lseek(fd, offset);
+        pos = fd->fptr;
         rt_mutex_release(&file->vnode->lock);
         if (result == FR_OK)
         {
             /* return current position */
-            return fd->fptr;
+            return pos;
         }
     }
     else if (file->vnode->type == FT_DIRECTORY)

Original file line number	Diff line number	Diff line change
`@@ -629,7 +629,7 @@ int dfs_elm_flush(struct dfs_file *file)`
`629`	`629`	`off_t dfs_elm_lseek(struct dfs_file *file, off_t offset, int wherece)`
`630`	`630`	`{`
`631`	`631`	`FRESULT result = FR_OK;`
`632`		`-`
	`632`	`+ off_t pos = 0;`
`633`	`633`	`switch (wherece)`
`634`	`634`	`{`
`635`	`635`	`case SEEK_SET:`
`@@ -656,11 +656,12 @@ off_t dfs_elm_lseek(struct dfs_file *file, off_t offset, int wherece)`
`656`	`656`	`RT_ASSERT(fd != RT_NULL);`
`657`	`657`	`rt_mutex_take(&file->vnode->lock, RT_WAITING_FOREVER);`
`658`	`658`	`result = f_lseek(fd, offset);`
	`659`	`+ pos = fd->fptr;`
`659`	`660`	`rt_mutex_release(&file->vnode->lock);`
`660`	`661`	`if (result == FR_OK)`
`661`	`662`	`{`
`662`	`663`	`/* return current position */`
`663`		`- return fd->fptr;`
	`664`	`+ return pos;`
`664`	`665`	`}`
`665`	`666`	`}`
`666`	`667`	`else if (file->vnode->type == FT_DIRECTORY)`