This is an automated email from the ASF dual-hosted git repository.
gnutt pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git
commit 7980673b590c3ac5893afe59510a45bbea1c7984
Author: Xiang Xiao <xiaoxi...@xiaomi.com>
AuthorDate: Sun May 3 01:25:16 2020 +0800
fs/vfs: Add nx_seek function
Signed-off-by: Xiang Xiao <xiaoxi...@xiaomi.com>
---
fs/vfs/fs_lseek.c | 75 +++++++++++++++++++++++++++++++--------------------
include/nuttx/fs/fs.h | 18 +++++++++++++
2 files changed, 64 insertions(+), 29 deletions(-)
diff --git a/fs/vfs/fs_lseek.c b/fs/vfs/fs_lseek.c
index 9322851..3500144 100644
--- a/fs/vfs/fs_lseek.c
+++ b/fs/vfs/fs_lseek.c
@@ -122,6 +122,40 @@ off_t file_seek(FAR struct file *filep, off_t offset, int
whence)
}
/****************************************************************************
+ * Name: nx_seek
+ *
+ * Description:
+ * nx_seek() function repositions the offset of the open file associated
+ * with the file descriptor fd to the argument 'offset' according to the
+ * directive 'whence'. nx_seek() is an internal OS function. It is
+ * functionally equivalent to lseek() except that:
+ *
+ * - It does not modify the errno variable, and
+ * - It is not a cancellation point.
+ *
+ ****************************************************************************/
+
+off_t nx_seek(int fd, off_t offset, int whence)
+{
+ FAR struct file *filep;
+ int ret;
+
+ /* Get the file structure corresponding to the file descriptor. */
+
+ ret = fs_getfilep(fd, &filep);
+ if (ret < 0)
+ {
+ return ret;
+ }
+
+ DEBUGASSERT(filep != NULL);
+
+ /* Then let file_seek do the real work */
+
+ return file_seek(filep, offset, whence);
+}
+
+/****************************************************************************
* Name: lseek
*
* Description:
@@ -136,10 +170,11 @@ off_t file_seek(FAR struct file *filep, off_t offset, int
whence)
* SEEK_END
* The offset is set to the size of the file plus offset bytes.
*
- * The lseek() function allows the file offset to be set beyond the end of the
- * file (but this does not change the size of the file). If data is later
written
- * at this point, subsequent reads of the data in the gap (a "hole") return
null
- * bytes ('\0') until data is actually written into the gap.
+ * The lseek() function allows the file offset to be set beyond the end of
+ * the file (but this does not change the size of the file). If data is
+ * later written at this point, subsequent reads of the data in the gap (a
+ * "hole") return null bytes ('\0') until data is actually written into the
+ * gap.
*
* Input Parameters:
* fd File descriptor of device
@@ -147,12 +182,12 @@ off_t file_seek(FAR struct file *filep, off_t offset, int
whence)
* whence Defines how to use offset
*
* Returned Value:
- * The resulting offset on success. -1 on failure withi errno set properly:
+ * The resulting offset on success. -1 on failure withi errno set properly:
*
* EBADF fd is not an open file descriptor.
* EINVAL whence is not one of SEEK_SET, SEEK_CUR, SEEK_END; or the
- * resulting file offset would be negative, or beyond the end of a
- * seekable device.
+ * resulting file offset would be negative, or beyond the end of
+ * a seekable device.
* EOVERFLOW The resulting file offset cannot be represented in an off_t.
* ESPIPE fd is associated with a pipe, socket, or FIFO.
*
@@ -160,34 +195,16 @@ off_t file_seek(FAR struct file *filep, off_t offset, int
whence)
off_t lseek(int fd, off_t offset, int whence)
{
- FAR struct file *filep;
off_t newpos;
- int errcode;
- int ret;
-
- /* Get the file structure corresponding to the file descriptor. */
- ret = fs_getfilep(fd, &filep);
- if (ret < 0)
- {
- errcode = -ret;
- goto errout;
- }
+ /* Let nx_seek do the real work */
- DEBUGASSERT(filep != NULL);
-
- /* Then let file_seek do the real work */
-
- newpos = file_seek(filep, offset, whence);
+ newpos = nx_seek(fd, offset, whence);
if (newpos < 0)
{
- errcode = (int)-newpos;
- goto errout;
+ set_errno(-newpos);
+ return ERROR;
}
return newpos;
-
-errout:
- set_errno(errcode);
- return (off_t)ERROR;
}
diff --git a/include/nuttx/fs/fs.h b/include/nuttx/fs/fs.h
index 3758db4..4640424 100644
--- a/include/nuttx/fs/fs.h
+++ b/include/nuttx/fs/fs.h
@@ -79,6 +79,7 @@
# endif
# define _NX_READ(f,b,s) nx_read(f,b,s)
# define _NX_WRITE(f,b,s) nx_write(f,b,s)
+# define _NX_SEEK(f,o,w) nx_seek(f,o,w)
# define _NX_GETERRNO(r) (-(r))
# define _NX_SETERRNO(r) set_errno(-(r))
# define _NX_GETERRVAL(r) (r)
@@ -90,6 +91,7 @@
# endif
# define _NX_READ(f,b,s) read(f,b,s)
# define _NX_WRITE(f,b,s) write(f,b,s)
+# define _NX_SEEK(f,o,w) lseek(f,o,w)
# define _NX_GETERRNO(r) errno
# define _NX_SETERRNO(r)
# define _NX_GETERRVAL(r) (-errno)
@@ -1161,6 +1163,22 @@ ssize_t file_pwrite(FAR struct file *filep, FAR const
void *buf,
off_t file_seek(FAR struct file *filep, off_t offset, int whence);
/****************************************************************************
+ * Name: nx_seek
+ *
+ * Description:
+ * nx_seek() function repositions the offset of the open file associated
+ * with the file descriptor fd to the argument 'offset' according to the
+ * directive 'whence'. nx_seek() is an internal OS function. It is
+ * functionally equivalent to lseek() except that:
+ *
+ * - It does not modify the errno variable, and
+ * - It is not a cancellation point.
+ *
+ ****************************************************************************/
+
+off_t nx_seek(int fd, off_t offset, int whence);
+
+/****************************************************************************
* Name: file_fsync
*
* Description:
