(nuttx) branch master updated: fs/vfs: Return the length that the file system gives from readlink().

[acassis]

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acassis pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/nuttx.git


The following commit(s) were added to refs/heads/master by this push:
     new 40d9ef45feb fs/vfs: Return the length that the file system gives from 
readlink().
40d9ef45feb is described below

commit 40d9ef45feb9e793bed51d9499ec6147df04013b
Author: Marco Casaroli <marco.casar...@gmail.com>
AuthorDate: Sun Oct 11 19:38:52 2026 +0200

    fs/vfs: Return the length that the file system gives from readlink().
    
    readlink() of a path in a mounted file system returned strlen() of the
    buffer.  The readlink method of a file system, like readlink(), returns
    the number of bytes it placed and does not add a null byte, so
    strlen() read past the target into old buffer contents.  readlink() now
    returns the length that the file system gives.
    
    Assisted-by: Claude Code:claude-opus-5-5
    Signed-off-by: Marco Casaroli <marco.casar...@gmail.com>
---
 fs/vfs/fs_readlink.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/fs/vfs/fs_readlink.c b/fs/vfs/fs_readlink.c
index 51f09ad18cc..2c613995c85 100644
--- a/fs/vfs/fs_readlink.c
+++ b/fs/vfs/fs_readlink.c
@@ -26,6 +26,7 @@
 
 #include <nuttx/config.h>
 
+#include <sys/param.h>
 #include <sys/types.h>
 #include <stdbool.h>
 #include <string.h>
@@ -71,6 +72,7 @@ ssize_t readlink(FAR const char *path, FAR char *buf, size_t 
bufsize)
 {
   struct inode_search_s desc;
   FAR struct inode *node;
+  ssize_t nread;
   int ret;
 
   DEBUGASSERT(path != NULL && buf != NULL && bufsize > 0);
@@ -102,9 +104,11 @@ ssize_t readlink(FAR const char *path, FAR char *buf, 
size_t bufsize)
     {
       if (node->u.i_mops && node->u.i_mops->readlink)
         {
-          ret = node->u.i_mops->readlink(node, desc.relpath, buf, bufsize);
-          if (ret < 0)
+          nread = node->u.i_mops->readlink(node, desc.relpath, buf,
+                                           bufsize);
+          if (nread < 0)
             {
+              ret = nread;
               goto errout_with_inode;
             }
         }
@@ -137,14 +141,15 @@ ssize_t readlink(FAR const char *path, FAR char *buf, 
size_t bufsize)
 
       /* Copy the link target path to the user-provided buffer. */
 
-      strlcpy(buf, node->u.i_link, bufsize);
+      nread = strlcpy(buf, node->u.i_link, bufsize);
+      nread = MIN(nread, bufsize);
     }
 
   /* Release our reference on the inode and return the length */
 
   inode_release(node);
   inode_search_release(&desc);
-  return strlen(buf);
+  return nread;
 
 errout_with_inode:
   inode_release(node);