From e7f7d2253c05143ed76ddc5e11f4cf0a9b814a27 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 29 Jan 2015 12:02:27 +0000 Subject: [PATCH] VFS: Add a whiteout dentry type Add DCACHE_WHITEOUT_TYPE and provide a d_is_whiteout() accessor function. A d_is_miss() accessor is also added for ordinary cache misses and d_is_negative() is modified to indicate either an ordinary miss or an enforced miss (whiteout). Signed-off-by: David Howells Signed-off-by: Al Viro --- include/linux/dcache.h | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 047c0db5763f..98d2a948a08e 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -215,11 +215,12 @@ struct dentry_operations { #define DCACHE_LRU_LIST 0x00080000 #define DCACHE_ENTRY_TYPE 0x00700000 -#define DCACHE_MISS_TYPE 0x00000000 /* Negative dentry */ -#define DCACHE_DIRECTORY_TYPE 0x00100000 /* Normal directory */ -#define DCACHE_AUTODIR_TYPE 0x00200000 /* Lookupless directory (presumed automount) */ -#define DCACHE_SYMLINK_TYPE 0x00300000 /* Symlink */ -#define DCACHE_FILE_TYPE 0x00400000 /* Other file type */ +#define DCACHE_MISS_TYPE 0x00000000 /* Negative dentry (maybe fallthru to nowhere) */ +#define DCACHE_WHITEOUT_TYPE 0x00100000 /* Whiteout dentry (stop pathwalk) */ +#define DCACHE_DIRECTORY_TYPE 0x00200000 /* Normal directory */ +#define DCACHE_AUTODIR_TYPE 0x00300000 /* Lookupless directory (presumed automount) */ +#define DCACHE_SYMLINK_TYPE 0x00400000 /* Symlink (or fallthru to such) */ +#define DCACHE_FILE_TYPE 0x00500000 /* Other file type (or fallthru to such) */ #define DCACHE_MAY_FREE 0x00800000 @@ -423,6 +424,16 @@ static inline unsigned __d_entry_type(const struct dentry *dentry) return dentry->d_flags & DCACHE_ENTRY_TYPE; } +static inline bool d_is_miss(const struct dentry *dentry) +{ + return __d_entry_type(dentry) == DCACHE_MISS_TYPE; +} + +static inline bool d_is_whiteout(const struct dentry *dentry) +{ + return __d_entry_type(dentry) == DCACHE_WHITEOUT_TYPE; +} + static inline bool d_can_lookup(const struct dentry *dentry) { return __d_entry_type(dentry) == DCACHE_DIRECTORY_TYPE; @@ -450,7 +461,8 @@ static inline bool d_is_file(const struct dentry *dentry) static inline bool d_is_negative(const struct dentry *dentry) { - return __d_entry_type(dentry) == DCACHE_MISS_TYPE; + // TODO: check d_is_whiteout(dentry) also. + return d_is_miss(dentry); } static inline bool d_is_positive(const struct dentry *dentry) -- 2.34.1