lkml.org 
[lkml]   [2018]   [Oct]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[RFC][PATCH v2 04/10] ext2: use common file type conversion
Deduplicate the ext2 file type conversion implementation.

Original patch by Amir Goldstein.

v2:
- Rebased against Linux 4.19 by Phillip Potter
- This version does not remove EXT2_FT_x enum from fs/ext2/ext2.h,
as these values are now used in compile-time checks added by
Phillip Potter to make sure they remain the same as FT_x values

v1:
- Initial implementation

Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
---
fs/ext2/dir.c | 51 ++++++++++++++++++++++-----------------------------
1 file changed, 22 insertions(+), 29 deletions(-)

diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index 3b8114def693..420d4b9e8980 100644
--- 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 +312,24 @@ 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];
+ /*
+ * compile-time asserts that generic FT_x types
+ * still match EXT2_FT_x types - no need to list
+ * for other functions as well as build will
+ * fail either way
+ */
+ BUILD_BUG_ON(EXT2_FT_UNKNOWN != FT_UNKNOWN);
+ BUILD_BUG_ON(EXT2_FT_REG_FILE != FT_REG_FILE);
+ BUILD_BUG_ON(EXT2_FT_DIR != FT_DIR);
+ BUILD_BUG_ON(EXT2_FT_CHRDEV != FT_CHRDEV);
+ BUILD_BUG_ON(EXT2_FT_BLKDEV != FT_BLKDEV);
+ BUILD_BUG_ON(EXT2_FT_FIFO != FT_FIFO);
+ BUILD_BUG_ON(EXT2_FT_SOCK != FT_SOCK);
+ BUILD_BUG_ON(EXT2_FT_SYMLINK != FT_SYMLINK);
+ BUILD_BUG_ON(EXT2_FT_MAX != FT_MAX);
+
+ if (has_filetype)
+ d_type = fs_dtype(de->file_type);

if (!dir_emit(ctx, de->name, de->name_len,
le32_to_cpu(de->inode),
--
2.17.2
\
 
 \ /
  Last update: 2018-10-23 23:20    [W:0.043 / U:2.468 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site