diff --git a/fs/vfs/fs_lseek.c b/fs/vfs/fs_lseek.c index 93228510b2..35001440b3 100644 --- a/fs/vfs/fs_lseek.c +++ b/fs/vfs/fs_lseek.c @@ -121,6 +121,40 @@ off_t file_seek(FAR struct file *filep, off_t offset, int whence) return filep->f_pos; } +/**************************************************************************** + * 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 * @@ -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. */ + /* Let nx_seek do the real work */ - ret = fs_getfilep(fd, &filep); - if (ret < 0) - { - errcode = -ret; - goto errout; - } - - 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 3758db421c..4640424e81 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) @@ -1160,6 +1162,22 @@ 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 *