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-rw-r--r--kernel/Documentation/filesystems/vfs.txt41
1 files changed, 24 insertions, 17 deletions
diff --git a/kernel/Documentation/filesystems/vfs.txt b/kernel/Documentation/filesystems/vfs.txt
index 5d833b32b..8c6f07ad3 100644
--- a/kernel/Documentation/filesystems/vfs.txt
+++ b/kernel/Documentation/filesystems/vfs.txt
@@ -350,8 +350,8 @@ struct inode_operations {
int (*rename2) (struct inode *, struct dentry *,
struct inode *, struct dentry *, unsigned int);
int (*readlink) (struct dentry *, char __user *,int);
- void * (*follow_link) (struct dentry *, struct nameidata *);
- void (*put_link) (struct dentry *, struct nameidata *, void *);
+ const char *(*follow_link) (struct dentry *, void **);
+ void (*put_link) (struct inode *, void *);
int (*permission) (struct inode *, int);
int (*get_acl)(struct inode *, int);
int (*setattr) (struct dentry *, struct iattr *);
@@ -436,16 +436,18 @@ otherwise noted.
follow_link: called by the VFS to follow a symbolic link to the
inode it points to. Only required if you want to support
- symbolic links. This method returns a void pointer cookie
- that is passed to put_link().
+ symbolic links. This method returns the symlink body
+ to traverse (and possibly resets the current position with
+ nd_jump_link()). If the body won't go away until the inode
+ is gone, nothing else is needed; if it needs to be otherwise
+ pinned, the data needed to release whatever we'd grabbed
+ is to be stored in void * variable passed by address to
+ follow_link() instance.
put_link: called by the VFS to release resources allocated by
- follow_link(). The cookie returned by follow_link() is passed
- to this method as the last parameter. It is used by
- filesystems such as NFS where page cache is not stable
- (i.e. page that was installed when the symbolic link walk
- started might not be in the page cache at the end of the
- walk).
+ follow_link(). The cookie stored by follow_link() is passed
+ to this method as the last parameter; only called when
+ cookie isn't NULL.
permission: called by the VFS to check for access rights on a POSIX-like
filesystem.
@@ -767,7 +769,7 @@ struct address_space_operations {
to stall to allow flushers a chance to complete some IO. Ordinarily
it can use PageDirty and PageWriteback but some filesystems have
more complex state (unstable pages in NFS prevent reclaim) or
- do not set those flags due to locking problems (jbd). This callback
+ do not set those flags due to locking problems. This callback
allows a filesystem to indicate to the VM if a page should be
treated as dirty or writeback for the purposes of stalling.
@@ -797,7 +799,7 @@ struct file_operations
----------------------
This describes how the VFS can manipulate an open file. As of kernel
-3.12, the following members are defined:
+4.1, the following members are defined:
struct file_operations {
struct module *owner;
@@ -811,8 +813,9 @@ struct file_operations {
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
int (*mmap) (struct file *, struct vm_area_struct *);
+ int (*mremap)(struct file *, struct vm_area_struct *);
int (*open) (struct inode *, struct file *);
- int (*flush) (struct file *);
+ int (*flush) (struct file *, fl_owner_t id);
int (*release) (struct inode *, struct file *);
int (*fsync) (struct file *, loff_t, loff_t, int datasync);
int (*aio_fsync) (struct kiocb *, int datasync);
@@ -822,11 +825,15 @@ struct file_operations {
unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
int (*check_flags)(int);
int (*flock) (struct file *, int, struct file_lock *);
- ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, size_t, unsigned int);
- ssize_t (*splice_read)(struct file *, struct pipe_inode_info *, size_t, unsigned int);
- int (*setlease)(struct file *, long arg, struct file_lock **, void **);
- long (*fallocate)(struct file *, int mode, loff_t offset, loff_t len);
+ ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
+ ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
+ int (*setlease)(struct file *, long, struct file_lock **, void **);
+ long (*fallocate)(struct file *file, int mode, loff_t offset,
+ loff_t len);
void (*show_fdinfo)(struct seq_file *m, struct file *f);
+#ifndef CONFIG_MMU
+ unsigned (*mmap_capabilities)(struct file *);
+#endif
};
Again, all methods are called without any locks being held, unless