redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

fs: common implementation of file type 

Many file systems use a copy&paste implementation
of dirent to on-disk file type conversions.

Create a common implementation to be used by file systems
with some useful conversion helpers to reduce open coded
file type conversions in file system code.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Signed-off-by: Jan Kara <jack@suse.cz>
hifive-unleashed-5.1
Phillip Potter 2019-01-21 00:54:27 +00:00 committed by Jan Kara
parent 49a57857ae
commit bbe7449e25
5 changed files with 184 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
MAINTAINERS
View File

@ -5881,6 +5881,7 @@ L: linux-fsdevel@vger.kernel.org
S: Maintained
F: fs/*
F: include/linux/fs.h
F: include/linux/fs_types.h
F: include/uapi/linux/fs.h
FINTEK F75375S HARDWARE MONITOR AND FAN CONTROLLER DRIVER

3
fs/Makefile
View File

@ -12,7 +12,8 @@ obj-y := open.o read_write.o file_table.o super.o \
attr.o bad_inode.o file.o filesystems.o namespace.o \
seq_file.o xattr.o libfs.o fs-writeback.o \
pnode.o splice.o sync.o utimes.o d_path.o \
stack.o fs_struct.o statfs.o fs_pin.o nsfs.o
stack.o fs_struct.o statfs.o fs_pin.o nsfs.o \
fs_types.o
ifeq ($(CONFIG_BLOCK),y)
obj-y += buffer.o block_dev.o direct-io.o mpage.o

105
fs/fs_types.c 100644
View File

@ -0,0 +1,105 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/fs.h>
#include <linux/export.h>
/*
* fs on-disk file type to dirent file type conversion
*/
static const unsigned char fs_dtype_by_ftype[FT_MAX] = {
[FT_UNKNOWN] = DT_UNKNOWN,
[FT_REG_FILE] = DT_REG,
[FT_DIR] = DT_DIR,
[FT_CHRDEV] = DT_CHR,
[FT_BLKDEV] = DT_BLK,
[FT_FIFO] = DT_FIFO,
[FT_SOCK] = DT_SOCK,
[FT_SYMLINK] = DT_LNK
};
/**
* fs_ftype_to_dtype() - fs on-disk file type to dirent type.
* @filetype: The on-disk file type to convert.
*
* This function converts the on-disk file type value (FT_*) to the directory
* entry type (DT_*).
*
* Context: Any context.
* Return:
* * DT_UNKNOWN - Unknown type
* * DT_FIFO - FIFO
* * DT_CHR - Character device
* * DT_DIR - Directory
* * DT_BLK - Block device
* * DT_REG - Regular file
* * DT_LNK - Symbolic link
* * DT_SOCK - Local-domain socket
*/
unsigned char fs_ftype_to_dtype(unsigned int filetype)
{
if (filetype >= FT_MAX)
return DT_UNKNOWN;
return fs_dtype_by_ftype[filetype];
}
EXPORT_SYMBOL_GPL(fs_ftype_to_dtype);
/*
* dirent file type to fs on-disk file type conversion
* Values not initialized explicitly are FT_UNKNOWN (0).
*/
static const unsigned char fs_ftype_by_dtype[DT_MAX] = {
[DT_REG] = FT_REG_FILE,
[DT_DIR] = FT_DIR,
[DT_LNK] = FT_SYMLINK,
[DT_CHR] = FT_CHRDEV,
[DT_BLK] = FT_BLKDEV,
[DT_FIFO] = FT_FIFO,
[DT_SOCK] = FT_SOCK,
};
/**
* fs_umode_to_ftype() - file mode to on-disk file type.
* @mode: The file mode to convert.
*
* This function converts the file mode value to the on-disk file type (FT_*).
*
* Context: Any context.
* Return:
* * FT_UNKNOWN - Unknown type
* * FT_REG_FILE - Regular file
* * FT_DIR - Directory
* * FT_CHRDEV - Character device
* * FT_BLKDEV - Block device
* * FT_FIFO - FIFO
* * FT_SOCK - Local-domain socket
* * FT_SYMLINK - Symbolic link
*/
unsigned char fs_umode_to_ftype(umode_t mode)
{
return fs_ftype_by_dtype[S_DT(mode)];
}
EXPORT_SYMBOL_GPL(fs_umode_to_ftype);
/**
* fs_umode_to_dtype() - file mode to dirent file type.
* @mode: The file mode to convert.
*
* This function converts the file mode value to the directory
* entry type (DT_*).
*
* Context: Any context.
* Return:
* * DT_UNKNOWN - Unknown type
* * DT_FIFO - FIFO
* * DT_CHR - Character device
* * DT_DIR - Directory
* * DT_BLK - Block device
* * DT_REG - Regular file
* * DT_LNK - Symbolic link
* * DT_SOCK - Local-domain socket
*/
unsigned char fs_umode_to_dtype(umode_t mode)
{
return fs_ftype_to_dtype(fs_umode_to_ftype(mode));
}
EXPORT_SYMBOL_GPL(fs_umode_to_dtype);

17
include/linux/fs.h
View File

@ -37,6 +37,7 @@
#include <linux/uuid.h>
#include <linux/errseq.h>
#include <linux/ioprio.h>
#include <linux/fs_types.h>
#include <asm/byteorder.h>
#include <uapi/linux/fs.h>
@ -1699,22 +1700,6 @@ int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
u64 phys, u64 len, u32 flags);
int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
/*
* File types
*
* NOTE! These match bits 12..15 of stat.st_mode
* (ie "(i_mode >> 12) & 15").
*/
#define DT_UNKNOWN 0
#define DT_FIFO 1
#define DT_CHR 2
#define DT_DIR 4
#define DT_BLK 6
#define DT_REG 8
#define DT_LNK 10
#define DT_SOCK 12
#define DT_WHT 14
/*
* This is the "filldir" function type, used by readdir() to let
* the kernel specify what kind of dirent layout it wants to have.

75
include/linux/fs_types.h 100644
View File

@ -0,0 +1,75 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_FS_TYPES_H
#define _LINUX_FS_TYPES_H
/*
* This is a header for the common implementation of dirent
* to fs on-disk file type conversion. Although the fs on-disk
* bits are specific to every file system, in practice, many
* file systems use the exact same on-disk format to describe
* the lower 3 file type bits that represent the 7 POSIX file
* types.
*
* It is important to note that the definitions in this
* header MUST NOT change. This would break both the
* userspace ABI and the on-disk format of filesystems
* using this code.
*
* All those file systems can use this generic code for the
* conversions.
*/
/*
* struct dirent file types
* exposed to user via getdents(2), readdir(3)
*
* These match bits 12..15 of stat.st_mode
* (ie "(i_mode >> 12) & 15").
*/
#define S_DT_SHIFT 12
#define S_DT(mode) (((mode) & S_IFMT) >> S_DT_SHIFT)
#define S_DT_MASK (S_IFMT >> S_DT_SHIFT)
/* these are defined by POSIX and also present in glibc's dirent.h */
#define DT_UNKNOWN 0
#define DT_FIFO 1
#define DT_CHR 2
#define DT_DIR 4
#define DT_BLK 6
#define DT_REG 8
#define DT_LNK 10
#define DT_SOCK 12
#define DT_WHT 14
#define DT_MAX (S_DT_MASK + 1) /* 16 */
/*
* fs on-disk file types.
* Only the low 3 bits are used for the POSIX file types.
* Other bits are reserved for fs private use.
* These definitions are shared and used by multiple filesystems,
* and MUST NOT change under any circumstances.
*
* Note that no fs currently stores the whiteout type on-disk,
* so whiteout dirents are exposed to user as DT_CHR.
*/
#define FT_UNKNOWN 0
#define FT_REG_FILE 1
#define FT_DIR 2
#define FT_CHRDEV 3
#define FT_BLKDEV 4
#define FT_FIFO 5
#define FT_SOCK 6
#define FT_SYMLINK 7
#define FT_MAX 8
/*
* declarations for helper functions, accompanying implementation
* is in fs/fs_types.c
*/
extern unsigned char fs_ftype_to_dtype(unsigned int filetype);
extern unsigned char fs_umode_to_ftype(umode_t mode);
extern unsigned char fs_umode_to_dtype(umode_t mode);
#endif