diff options
author | Miklos Szeredi <mszeredi@redhat.com> | 2016-06-30 08:53:27 +0200 |
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committer | Miklos Szeredi <mszeredi@redhat.com> | 2016-06-30 08:53:27 +0200 |
commit | e698b8a43659f9ece192fcab215abcadac8f88d7 (patch) | |
tree | 73bcdb2ecc6a7fe314d380ac2373ff53d5f935ae /Documentation | |
parent | 2d902671ce1cd98cdc88d78c481889a1b2996101 (diff) |
vfs: document ->d_real()
Add missing documentation for the d_op->d_real() method and d_real()
helper.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/filesystems/Locking | 3 | ||||
-rw-r--r-- | Documentation/filesystems/vfs.txt | 20 |
2 files changed, 23 insertions, 0 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 75eea7ce3d7c..898d3cecd8a6 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -20,6 +20,8 @@ prototypes: char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen); struct vfsmount *(*d_automount)(struct path *path); int (*d_manage)(struct dentry *, bool); + struct dentry *(*d_real)(struct dentry *, const struct inode *, + unsigned int); locking rules: rename_lock ->d_lock may block rcu-walk @@ -34,6 +36,7 @@ d_iput: no no yes no d_dname: no no no no d_automount: no no yes no d_manage: no no yes (ref-walk) maybe +d_real no no yes no --------------------------- inode_operations --------------------------- prototypes: diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index c61a223ef3ff..1c934dd2c47d 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -938,6 +938,8 @@ struct dentry_operations { char *(*d_dname)(struct dentry *, char *, int); struct vfsmount *(*d_automount)(struct path *); int (*d_manage)(struct dentry *, bool); + struct dentry *(*d_real)(struct dentry *, const struct inode *, + unsigned int); }; d_revalidate: called when the VFS needs to revalidate a dentry. This @@ -1060,6 +1062,24 @@ struct dentry_operations { This function is only used if DCACHE_MANAGE_TRANSIT is set on the dentry being transited from. + d_real: overlay/union type filesystems implement this method to return one of + the underlying dentries hidden by the overlay. It is used in three + different modes: + + Called from open it may need to copy-up the file depending on the + supplied open flags. This mode is selected with a non-zero flags + argument. In this mode the d_real method can return an error. + + Called from file_dentry() it returns the real dentry matching the inode + argument. The real dentry may be from a lower layer already copied up, + but still referenced from the file. This mode is selected with a + non-NULL inode argument. This will always succeed. + + With NULL inode and zero flags the topmost real underlying dentry is + returned. This will always succeed. + + This method is never called with both non-NULL inode and non-zero flags. + Example : static char *pipefs_dname(struct dentry *dent, char *buffer, int buflen) |