[PATCH 13/38] fallthru: Basic fallthru definitions
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From: Valerie Aurora on 6 Aug 2010 18:50 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(a)redhat.com> --- 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 964e0fc..bbaefa9 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 79b9f6a..249d077 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -992,7 +992,7 @@ 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 7d650a2..0904716 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; @@ -379,6 +381,11 @@ 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 1dbe156..71ee74e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -210,6 +210,7 @@ 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_ACTIVE (1<<30) #define MS_NOUSER (1<<31) @@ -1534,6 +1535,7 @@ 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); -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |