From: Valerie Aurora <vaurora@xxxxxxxxxx> Define the fallthru dcache flag and file system op. Mask out the DCACHE_FALLTHRU flag on dentry creation. Actual users and changes to lookup come in later patches. Signed-off-by: Valerie Aurora <vaurora@xxxxxxxxxx> Signed-off-by: Valerie Aurora <valerie.aurora@xxxxxxxxx> --- Documentation/filesystems/vfs.txt | 6 ++++++ fs/dcache.c | 2 +- include/linux/dcache.h | 7 +++++++ include/linux/fs.h | 2 ++ 4 files changed, 16 insertions(+), 1 deletions(-) diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 05c73b1..ecfc4f9 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -320,6 +320,7 @@ struct inode_operations { int (*rmdir) (struct inode *,struct dentry *); int (*mknod) (struct inode *,struct dentry *,int,dev_t); int (*whiteout) (struct inode *, struct dentry *, struct dentry *); + int (*fallthru) (struct inode *, struct dentry *); int (*rename) (struct inode *, struct dentry *, struct inode *, struct dentry *); int (*readlink) (struct dentry *, char __user *,int); @@ -390,6 +391,11 @@ otherwise noted. second is the dentry for the whiteout itself. This method must unlink() or rmdir() the original entry if it exists. + fallthru: called by the readdir(2) system call on a layered file + system. Only required if you want to support fallthrus. + Fallthrus are place-holders for directory entries visible from + a lower level file system. + rename: called by the rename(2) system call to rename the object to have the parent and name given by the second inode and dentry. diff --git a/fs/dcache.c b/fs/dcache.c index 9358dbc..5a0e3f5 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -994,7 +994,7 @@ EXPORT_SYMBOL(d_alloc_name); static void __d_instantiate(struct dentry *dentry, struct inode *inode) { if (inode) { - dentry->d_flags &= ~DCACHE_WHITEOUT; + dentry->d_flags &= ~(DCACHE_WHITEOUT|DCACHE_FALLTHRU); list_add(&dentry->d_alias, &inode->i_dentry); } dentry->d_inode = inode; diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 6e66b76..19ddb8c 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -190,6 +190,8 @@ d_iput: no no no yes #define DCACHE_WHITEOUT 0x0200 /* Stop lookup in a unioned file system */ +#define DCACHE_FALLTHRU 0x0400 /* Continue lookup below an opaque dir */ + extern spinlock_t dcache_lock; extern seqlock_t rename_lock; @@ -381,6 +383,11 @@ static inline int d_is_whiteout(struct dentry *dentry) return (dentry->d_flags & DCACHE_WHITEOUT); } +static inline int d_is_fallthru(struct dentry *dentry) +{ + return (dentry->d_flags & DCACHE_FALLTHRU); +} + static inline struct dentry *dget_parent(struct dentry *dentry) { struct dentry *ret; diff --git a/include/linux/fs.h b/include/linux/fs.h index 9d6e72f..92d248b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -209,6 +209,7 @@ struct inodes_stat_t { #define MS_I_VERSION (1<<23) /* Update inode I_version field */ #define MS_STRICTATIME (1<<24) /* Always perform atime updates */ #define MS_WHITEOUT (1<<25) /* FS supports whiteout filetype */ +#define MS_FALLTHRU (1<<26) /* FS supports fallthru filetype */ #define MS_BORN (1<<29) #define MS_ACTIVE (1<<30) #define MS_NOUSER (1<<31) @@ -1525,6 +1526,7 @@ struct inode_operations { int (*rmdir) (struct inode *,struct dentry *); int (*mknod) (struct inode *,struct dentry *,int,dev_t); int (*whiteout) (struct inode *, struct dentry *, struct dentry *); + int (*fallthru) (struct inode *, struct dentry *); int (*rename) (struct inode *, struct dentry *, struct inode *, struct dentry *); int (*readlink) (struct dentry *, char __user *,int); -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html