diff options
| -rw-r--r-- | fs/dcache.c | 5 | ||||
| -rw-r--r-- | fs/overlayfs/super.c | 33 | ||||
| -rw-r--r-- | include/linux/dcache.h | 10 | ||||
| -rw-r--r-- | include/linux/fs.h | 10 |
4 files changed, 57 insertions, 1 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 877bcbbd03ff..18effa378f97 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1666,7 +1666,8 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op) DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE | DCACHE_OP_DELETE | - DCACHE_OP_SELECT_INODE)); + DCACHE_OP_SELECT_INODE | + DCACHE_OP_REAL)); dentry->d_op = op; if (!op) return; @@ -1684,6 +1685,8 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op) dentry->d_flags |= DCACHE_OP_PRUNE; if (op->d_select_inode) dentry->d_flags |= DCACHE_OP_SELECT_INODE; + if (op->d_real) + dentry->d_flags |= DCACHE_OP_REAL; } EXPORT_SYMBOL(d_set_d_op); diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 000b2ed05c29..a1acc6004a91 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -276,6 +276,37 @@ static void ovl_dentry_release(struct dentry *dentry) } } +static struct dentry *ovl_d_real(struct dentry *dentry, struct inode *inode) +{ + struct dentry *real; + + if (d_is_dir(dentry)) { + if (!inode || inode == d_inode(dentry)) + return dentry; + goto bug; + } + + real = ovl_dentry_upper(dentry); + if (real && (!inode || inode == d_inode(real))) + return real; + + real = ovl_dentry_lower(dentry); + if (!real) + goto bug; + + if (!inode || inode == d_inode(real)) + return real; + + /* Handle recursion */ + if (real->d_flags & DCACHE_OP_REAL) + return real->d_op->d_real(real, inode); + +bug: + WARN(1, "ovl_d_real(%pd4, %s:%lu\n): real dentry not found\n", dentry, + inode ? inode->i_sb->s_id : "NULL", inode ? inode->i_ino : 0); + return dentry; +} + static int ovl_dentry_revalidate(struct dentry *dentry, unsigned int flags) { struct ovl_entry *oe = dentry->d_fsdata; @@ -320,11 +351,13 @@ static int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags) static const struct dentry_operations ovl_dentry_operations = { .d_release = ovl_dentry_release, .d_select_inode = ovl_d_select_inode, + .d_real = ovl_d_real, }; static const struct dentry_operations ovl_reval_dentry_operations = { .d_release = ovl_dentry_release, .d_select_inode = ovl_d_select_inode, + .d_real = ovl_d_real, .d_revalidate = ovl_dentry_revalidate, .d_weak_revalidate = ovl_dentry_weak_revalidate, }; diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 8a2e009c8a5a..f513dd855cb2 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -161,6 +161,7 @@ struct dentry_operations { struct vfsmount *(*d_automount)(struct path *); int (*d_manage)(struct dentry *, bool); struct inode *(*d_select_inode)(struct dentry *, unsigned); + struct dentry *(*d_real)(struct dentry *, struct inode *); } ____cacheline_aligned; /* @@ -227,6 +228,7 @@ struct dentry_operations { #define DCACHE_MAY_FREE 0x00800000 #define DCACHE_FALLTHRU 0x01000000 /* Fall through to lower layer */ #define DCACHE_OP_SELECT_INODE 0x02000000 /* Unioned entry: dcache op selects inode */ +#define DCACHE_OP_REAL 0x08000000 extern seqlock_t rename_lock; @@ -582,4 +584,12 @@ static inline struct dentry *d_backing_dentry(struct dentry *upper) return upper; } +static inline struct dentry *d_real(struct dentry *dentry) +{ + if (unlikely(dentry->d_flags & DCACHE_OP_REAL)) + return dentry->d_op->d_real(dentry, NULL); + else + return dentry; +} + #endif /* __LINUX_DCACHE_H */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 22c5a0cf16e3..ab3d8d9bb3ef 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1207,6 +1207,16 @@ static inline struct inode *file_inode(const struct file *f) return f->f_inode; } +static inline struct dentry *file_dentry(const struct file *file) +{ + struct dentry *dentry = file->f_path.dentry; + + if (unlikely(dentry->d_flags & DCACHE_OP_REAL)) + return dentry->d_op->d_real(dentry, file_inode(file)); + else + return dentry; +} + static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl) { return locks_lock_inode_wait(file_inode(filp), fl); |