Merge branch 'd_real' into overlayfs-next
This commit is contained in:
Miklos Szeredi
Коммит
1b91dbdd29
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@ -20,6 +20,8 @@ prototypes:
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char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen);
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struct vfsmount *(*d_automount)(struct path *path);
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int (*d_manage)(struct dentry *, bool);
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struct dentry *(*d_real)(struct dentry *, const struct inode *,
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unsigned int);
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locking rules:
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rename_lock ->d_lock may block rcu-walk
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@ -34,6 +36,7 @@ d_iput: no no yes no
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d_dname: no no no no
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d_automount: no no yes no
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d_manage: no no yes (ref-walk) maybe
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d_real no no yes no
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--------------------------- inode_operations ---------------------------
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prototypes:
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@ -66,7 +69,6 @@ prototypes:
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struct file *, unsigned open_flag,
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umode_t create_mode, int *opened);
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int (*tmpfile) (struct inode *, struct dentry *, umode_t);
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int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
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locking rules:
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all may block
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@ -95,7 +97,6 @@ fiemap: no
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update_time: no
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atomic_open: yes
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tmpfile: no
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dentry_open: no
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Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on
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victim.
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@ -364,7 +364,6 @@ struct inode_operations {
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int (*atomic_open)(struct inode *, struct dentry *, struct file *,
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unsigned open_flag, umode_t create_mode, int *opened);
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int (*tmpfile) (struct inode *, struct dentry *, umode_t);
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int (*dentry_open)(struct dentry *, struct file *, const struct cred *);
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};
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Again, all methods are called without any locks being held, unless
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@ -696,13 +695,6 @@ struct address_space_operations {
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but instead uses bmap to find out where the blocks in the file
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are and uses those addresses directly.
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dentry_open: *WARNING: probably going away soon, do not use!* This is an
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alternative to f_op->open(), the difference is that this method may open
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a file not necessarily originating from the same filesystem as the one
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i_op->open() was called on. It may be useful for stacking filesystems
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which want to allow native I/O directly on underlying files.
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invalidatepage: If a page has PagePrivate set, then invalidatepage
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will be called when part or all of the page is to be removed
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from the address space. This generally corresponds to either a
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@ -938,6 +930,8 @@ struct dentry_operations {
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char *(*d_dname)(struct dentry *, char *, int);
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struct vfsmount *(*d_automount)(struct path *);
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int (*d_manage)(struct dentry *, bool);
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struct dentry *(*d_real)(struct dentry *, const struct inode *,
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unsigned int);
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};
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d_revalidate: called when the VFS needs to revalidate a dentry. This
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@ -1022,6 +1016,14 @@ struct dentry_operations {
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at the end of the buffer, and returns a pointer to the first char.
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dynamic_dname() helper function is provided to take care of this.
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Example :
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static char *pipefs_dname(struct dentry *dent, char *buffer, int buflen)
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{
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return dynamic_dname(dentry, buffer, buflen, "pipe:[%lu]",
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dentry->d_inode->i_ino);
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}
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d_automount: called when an automount dentry is to be traversed (optional).
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This should create a new VFS mount record and return the record to the
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caller. The caller is supplied with a path parameter giving the
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@ -1060,13 +1062,23 @@ struct dentry_operations {
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This function is only used if DCACHE_MANAGE_TRANSIT is set on the
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dentry being transited from.
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Example :
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d_real: overlay/union type filesystems implement this method to return one of
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the underlying dentries hidden by the overlay. It is used in three
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different modes:
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static char *pipefs_dname(struct dentry *dent, char *buffer, int buflen)
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{
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return dynamic_dname(dentry, buffer, buflen, "pipe:[%lu]",
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dentry->d_inode->i_ino);
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}
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Called from open it may need to copy-up the file depending on the
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supplied open flags. This mode is selected with a non-zero flags
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argument. In this mode the d_real method can return an error.
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Called from file_dentry() it returns the real dentry matching the inode
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argument. The real dentry may be from a lower layer already copied up,
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but still referenced from the file. This mode is selected with a
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non-NULL inode argument. This will always succeed.
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With NULL inode and zero flags the topmost real underlying dentry is
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returned. This will always succeed.
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This method is never called with both non-NULL inode and non-zero flags.
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Each dentry has a pointer to its parent dentry, as well as a hash list
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of child dentries. Child dentries are basically like files in a
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@ -1729,7 +1729,6 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
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DCACHE_OP_REVALIDATE |
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DCACHE_OP_WEAK_REVALIDATE |
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DCACHE_OP_DELETE |
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DCACHE_OP_SELECT_INODE |
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DCACHE_OP_REAL));
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dentry->d_op = op;
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if (!op)
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@ -1746,8 +1745,6 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
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dentry->d_flags |= DCACHE_OP_DELETE;
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if (op->d_prune)
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dentry->d_flags |= DCACHE_OP_PRUNE;
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if (op->d_select_inode)
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dentry->d_flags |= DCACHE_OP_SELECT_INODE;
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if (op->d_real)
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dentry->d_flags |= DCACHE_OP_REAL;
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@ -4328,7 +4328,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
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* Check source == target.
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* On overlayfs need to look at underlying inodes.
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*/
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if (vfs_select_inode(old_dentry, 0) == vfs_select_inode(new_dentry, 0))
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if (d_real_inode(old_dentry) == d_real_inode(new_dentry))
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return 0;
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error = may_delete(old_dir, old_dentry, is_dir);
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@ -840,13 +840,13 @@ EXPORT_SYMBOL(file_path);
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int vfs_open(const struct path *path, struct file *file,
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const struct cred *cred)
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{
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struct inode *inode = vfs_select_inode(path->dentry, file->f_flags);
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struct dentry *dentry = d_real(path->dentry, NULL, file->f_flags);
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if (IS_ERR(inode))
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return PTR_ERR(inode);
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if (IS_ERR(dentry))
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return PTR_ERR(dentry);
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file->f_path = *path;
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return do_dentry_open(file, inode, NULL, cred);
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return do_dentry_open(file, d_backing_inode(dentry), NULL, cred);
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}
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struct file *dentry_open(const struct path *path, int flags,
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@ -351,36 +351,25 @@ static bool ovl_open_need_copy_up(int flags, enum ovl_path_type type,
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return true;
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}
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struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags)
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int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags)
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{
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int err;
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int err = 0;
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struct path realpath;
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enum ovl_path_type type;
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if (d_is_dir(dentry))
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return d_backing_inode(dentry);
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type = ovl_path_real(dentry, &realpath);
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if (ovl_open_need_copy_up(file_flags, type, realpath.dentry)) {
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err = ovl_want_write(dentry);
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if (err)
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return ERR_PTR(err);
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if (file_flags & O_TRUNC)
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err = ovl_copy_up_truncate(dentry);
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else
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err = ovl_copy_up(dentry);
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ovl_drop_write(dentry);
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if (err)
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return ERR_PTR(err);
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ovl_path_upper(dentry, &realpath);
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if (!err) {
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if (file_flags & O_TRUNC)
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err = ovl_copy_up_truncate(dentry);
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else
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err = ovl_copy_up(dentry);
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ovl_drop_write(dentry);
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}
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}
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if (realpath.dentry->d_flags & DCACHE_OP_SELECT_INODE)
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return realpath.dentry->d_op->d_select_inode(realpath.dentry, file_flags);
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return d_backing_inode(realpath.dentry);
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return err;
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}
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static const struct inode_operations ovl_file_inode_operations = {
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@ -179,7 +179,7 @@ ssize_t ovl_getxattr(struct dentry *dentry, struct inode *inode,
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const char *name, void *value, size_t size);
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ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
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int ovl_removexattr(struct dentry *dentry, const char *name);
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struct inode *ovl_d_select_inode(struct dentry *dentry, unsigned file_flags);
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int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags);
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struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
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struct ovl_entry *oe);
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@ -304,7 +304,9 @@ static void ovl_dentry_release(struct dentry *dentry)
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}
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}
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static struct dentry *ovl_d_real(struct dentry *dentry, struct inode *inode)
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static struct dentry *ovl_d_real(struct dentry *dentry,
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const struct inode *inode,
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unsigned int open_flags)
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{
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struct dentry *real;
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@ -314,6 +316,16 @@ static struct dentry *ovl_d_real(struct dentry *dentry, struct inode *inode)
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goto bug;
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}
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if (d_is_negative(dentry))
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return dentry;
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if (open_flags) {
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int err = ovl_open_maybe_copy_up(dentry, open_flags);
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if (err)
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return ERR_PTR(err);
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}
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real = ovl_dentry_upper(dentry);
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if (real && (!inode || inode == d_inode(real)))
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return real;
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@ -326,9 +338,7 @@ static struct dentry *ovl_d_real(struct dentry *dentry, struct inode *inode)
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return real;
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/* Handle recursion */
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if (real->d_flags & DCACHE_OP_REAL)
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return real->d_op->d_real(real, inode);
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return d_real(real, inode, open_flags);
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bug:
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WARN(1, "ovl_d_real(%pd4, %s:%lu\n): real dentry not found\n", dentry,
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inode ? inode->i_sb->s_id : "NULL", inode ? inode->i_ino : 0);
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@ -378,13 +388,11 @@ static int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags)
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static const struct dentry_operations ovl_dentry_operations = {
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.d_release = ovl_dentry_release,
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.d_select_inode = ovl_d_select_inode,
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.d_real = ovl_d_real,
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};
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static const struct dentry_operations ovl_reval_dentry_operations = {
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.d_release = ovl_dentry_release,
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.d_select_inode = ovl_d_select_inode,
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.d_real = ovl_d_real,
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.d_revalidate = ovl_dentry_revalidate,
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.d_weak_revalidate = ovl_dentry_weak_revalidate,
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|
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@ -139,8 +139,8 @@ struct dentry_operations {
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char *(*d_dname)(struct dentry *, char *, int);
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struct vfsmount *(*d_automount)(struct path *);
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int (*d_manage)(struct dentry *, bool);
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struct inode *(*d_select_inode)(struct dentry *, unsigned);
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struct dentry *(*d_real)(struct dentry *, struct inode *);
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struct dentry *(*d_real)(struct dentry *, const struct inode *,
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unsigned int);
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} ____cacheline_aligned;
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/*
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@ -206,10 +206,8 @@ struct dentry_operations {
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#define DCACHE_MAY_FREE 0x00800000
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#define DCACHE_FALLTHRU 0x01000000 /* Fall through to lower layer */
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#define DCACHE_OP_SELECT_INODE 0x02000000 /* Unioned entry: dcache op selects inode */
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#define DCACHE_ENCRYPTED_WITH_KEY 0x04000000 /* dir is encrypted with a valid key */
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#define DCACHE_OP_REAL 0x08000000
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#define DCACHE_ENCRYPTED_WITH_KEY 0x02000000 /* dir is encrypted with a valid key */
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#define DCACHE_OP_REAL 0x04000000
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#define DCACHE_PAR_LOOKUP 0x10000000 /* being looked up (with parent locked shared) */
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#define DCACHE_DENTRY_CURSOR 0x20000000
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@ -557,25 +555,27 @@ static inline struct dentry *d_backing_dentry(struct dentry *upper)
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return upper;
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}
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static inline struct dentry *d_real(struct dentry *dentry)
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/**
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* d_real - Return the real dentry
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* @dentry: the dentry to query
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* @inode: inode to select the dentry from multiple layers (can be NULL)
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* @flags: open flags to control copy-up behavior
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*
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* If dentry is on an union/overlay, then return the underlying, real dentry.
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* Otherwise return the dentry itself.
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*
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* See also: Documentation/filesystems/vfs.txt
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*/
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static inline struct dentry *d_real(struct dentry *dentry,
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const struct inode *inode,
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unsigned int flags)
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{
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if (unlikely(dentry->d_flags & DCACHE_OP_REAL))
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return dentry->d_op->d_real(dentry, NULL);
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return dentry->d_op->d_real(dentry, inode, flags);
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else
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return dentry;
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}
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static inline struct inode *vfs_select_inode(struct dentry *dentry,
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unsigned open_flags)
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{
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struct inode *inode = d_inode(dentry);
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if (inode && unlikely(dentry->d_flags & DCACHE_OP_SELECT_INODE))
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inode = dentry->d_op->d_select_inode(dentry, open_flags);
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return inode;
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}
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/**
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* d_real_inode - Return the real inode
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* @dentry: The dentry to query
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@ -585,7 +585,7 @@ static inline struct inode *vfs_select_inode(struct dentry *dentry,
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*/
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static inline struct inode *d_real_inode(struct dentry *dentry)
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{
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return d_backing_inode(d_real(dentry));
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return d_backing_inode(d_real(dentry, NULL, 0));
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}
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|
|
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@ -1272,12 +1272,7 @@ static inline struct inode *file_inode(const struct file *f)
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static inline struct dentry *file_dentry(const struct file *file)
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{
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struct dentry *dentry = file->f_path.dentry;
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if (unlikely(dentry->d_flags & DCACHE_OP_REAL))
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return dentry->d_op->d_real(dentry, file_inode(file));
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else
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return dentry;
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return d_real(file->f_path.dentry, file_inode(file), 0);
|
||||
}
|
||||
|
||||
static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl)
|
||||
|
|
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