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 <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
David Howells 2015-01-29 12:02:27 +00:00 committed by Al Viro
parent 155e35d4da
commit e7f7d2253c
1 changed files with 18 additions and 6 deletions

View File

@ -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)