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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2015-07-20 19:08:17 +0200
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2015-07-20 19:08:17 +0200
commitc57d5621d2f2dc238f4b9c4d00b2a54187a75445 (patch)
treeece13738a44545fb110e5d73adbf2625bc7a1ea6 /Documentation/filesystems/vfs.txt
parentInput: elan_i2c - enable ELAN0600 acpi panels (diff)
parentLinux 4.2-rc3 (diff)
downloadlinux-c57d5621d2f2dc238f4b9c4d00b2a54187a75445.tar.xz
linux-c57d5621d2f2dc238f4b9c4d00b2a54187a75445.zip
Merge tag 'v4.2-rc3' into next
Sync up with Linux 4.2-rc3 to bring in infrastructure (OF) pieces.
Diffstat (limited to 'Documentation/filesystems/vfs.txt')
-rw-r--r--Documentation/filesystems/vfs.txt47
1 files changed, 24 insertions, 23 deletions
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 966b22829f3b..5eb8456fc41e 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/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.
@@ -590,7 +592,7 @@ struct address_space_operations {
void (*invalidatepage) (struct page *, unsigned int, unsigned int);
int (*releasepage) (struct page *, int);
void (*freepage)(struct page *);
- ssize_t (*direct_IO)(int, struct kiocb *, struct iov_iter *iter, loff_t offset);
+ ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter, loff_t offset);
/* migrate the contents of a page to the specified target */
int (*migratepage) (struct page *, struct page *);
int (*launder_page) (struct page *);
@@ -797,15 +799,13 @@ 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;
loff_t (*llseek) (struct file *, loff_t, int);
ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
- ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
- ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
int (*iterate) (struct file *, struct dir_context *);
@@ -813,8 +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);
@@ -824,11 +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
@@ -838,14 +843,10 @@ otherwise noted.
read: called by read(2) and related system calls
- aio_read: vectored, possibly asynchronous read
-
read_iter: possibly asynchronous read with iov_iter as destination
write: called by write(2) and related system calls
- aio_write: vectored, possibly asynchronous write
-
write_iter: possibly asynchronous write with iov_iter as source
iterate: called when the VFS needs to read the directory contents