whiterose

linux unikernel
Log | Files | Refs | README | LICENSE | git clone https://git.ne02ptzero.me/git/whiterose

commit b39a07a5e073ba783cd86b60c77044587ddbf8a1
parent f90d64483ebd394958841f67f8794ab203b319a7
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Thu,  7 Mar 2019 08:23:17 -0800

Merge tag 'dtype_for_v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull dtype handling cleanups from Jan Kara:
 "A reworked dtype cleanup patches based on your feedback to the
  previous version of these.

  Again the series includes only the generic code and ext2 cleanup as a
  sample. The plan is to push cleanups for other filesystems separately
  through respective trees once the generic code lands to reduce the
  number of conflicts"

* tag 'dtype_for_v5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  ext2: use common file type conversion
  fs: common implementation of file type

Diffstat:
MMAINTAINERS | 1+
Mfs/Makefile | 3++-
Mfs/ext2/dir.c | 35++++++-----------------------------
Mfs/ext2/ext2.h | 16----------------
Afs/fs_types.c | 105+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Minclude/linux/fs.h | 17+----------------
Ainclude/linux/fs_types.h | 75+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
7 files changed, 190 insertions(+), 62 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS @@ -5947,6 +5947,7 @@ 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 diff --git a/fs/Makefile b/fs/Makefile @@ -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 diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c @@ -252,33 +252,10 @@ ext2_validate_entry(char *base, unsigned offset, unsigned mask) return (char *)p - base; } -static unsigned char ext2_filetype_table[EXT2_FT_MAX] = { - [EXT2_FT_UNKNOWN] = DT_UNKNOWN, - [EXT2_FT_REG_FILE] = DT_REG, - [EXT2_FT_DIR] = DT_DIR, - [EXT2_FT_CHRDEV] = DT_CHR, - [EXT2_FT_BLKDEV] = DT_BLK, - [EXT2_FT_FIFO] = DT_FIFO, - [EXT2_FT_SOCK] = DT_SOCK, - [EXT2_FT_SYMLINK] = DT_LNK, -}; - -#define S_SHIFT 12 -static unsigned char ext2_type_by_mode[S_IFMT >> S_SHIFT] = { - [S_IFREG >> S_SHIFT] = EXT2_FT_REG_FILE, - [S_IFDIR >> S_SHIFT] = EXT2_FT_DIR, - [S_IFCHR >> S_SHIFT] = EXT2_FT_CHRDEV, - [S_IFBLK >> S_SHIFT] = EXT2_FT_BLKDEV, - [S_IFIFO >> S_SHIFT] = EXT2_FT_FIFO, - [S_IFSOCK >> S_SHIFT] = EXT2_FT_SOCK, - [S_IFLNK >> S_SHIFT] = EXT2_FT_SYMLINK, -}; - static inline void ext2_set_de_type(ext2_dirent *de, struct inode *inode) { - umode_t mode = inode->i_mode; if (EXT2_HAS_INCOMPAT_FEATURE(inode->i_sb, EXT2_FEATURE_INCOMPAT_FILETYPE)) - de->file_type = ext2_type_by_mode[(mode & S_IFMT)>>S_SHIFT]; + de->file_type = fs_umode_to_ftype(inode->i_mode); else de->file_type = 0; } @@ -293,14 +270,14 @@ ext2_readdir(struct file *file, struct dir_context *ctx) unsigned long n = pos >> PAGE_SHIFT; unsigned long npages = dir_pages(inode); unsigned chunk_mask = ~(ext2_chunk_size(inode)-1); - unsigned char *types = NULL; bool need_revalidate = !inode_eq_iversion(inode, file->f_version); + bool has_filetype; if (pos > inode->i_size - EXT2_DIR_REC_LEN(1)) return 0; - if (EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE)) - types = ext2_filetype_table; + has_filetype = + EXT2_HAS_INCOMPAT_FEATURE(sb, EXT2_FEATURE_INCOMPAT_FILETYPE); for ( ; n < npages; n++, offset = 0) { char *kaddr, *limit; @@ -335,8 +312,8 @@ ext2_readdir(struct file *file, struct dir_context *ctx) if (de->inode) { unsigned char d_type = DT_UNKNOWN; - if (types && de->file_type < EXT2_FT_MAX) - d_type = types[de->file_type]; + if (has_filetype) + d_type = fs_ftype_to_dtype(de->file_type); if (!dir_emit(ctx, de->name, de->name_len, le32_to_cpu(de->inode), diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h @@ -604,22 +604,6 @@ struct ext2_dir_entry_2 { }; /* - * Ext2 directory file types. Only the low 3 bits are used. The - * other bits are reserved for now. - */ -enum { - EXT2_FT_UNKNOWN = 0, - EXT2_FT_REG_FILE = 1, - EXT2_FT_DIR = 2, - EXT2_FT_CHRDEV = 3, - EXT2_FT_BLKDEV = 4, - EXT2_FT_FIFO = 5, - EXT2_FT_SOCK = 6, - EXT2_FT_SYMLINK = 7, - EXT2_FT_MAX -}; - -/* * EXT2_DIR_PAD defines the directory entries boundaries * * NOTE: It must be a multiple of 4 diff --git a/fs/fs_types.c b/fs/fs_types.c @@ -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); diff --git a/include/linux/fs.h b/include/linux/fs.h @@ -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> @@ -1707,22 +1708,6 @@ int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical, 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. * This allows the kernel to read directories into kernel space or diff --git a/include/linux/fs_types.h b/include/linux/fs_types.h @@ -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