struct file_system_type {
const char *name;
int fs_flags;
- struct dentry *(*mount) (struct file_system_type *, int,
- const char *, void *);
- void (*kill_sb) (struct super_block *);
- struct module *owner;
- struct file_system_type * next;
- struct list_head fs_supers;
+ struct dentry *(*mount) (struct file_system_type *, int,
+ const char *, void *);
+ void (*kill_sb) (struct super_block *);
+ struct module *owner;
+ struct file_system_type * next;
+ struct list_head fs_supers;
struct lock_class_key s_lock_key;
struct lock_class_key s_umount_key;
};
filesystem. As of kernel 2.6.22, the following members are defined:
struct super_operations {
- struct inode *(*alloc_inode)(struct super_block *sb);
- void (*destroy_inode)(struct inode *);
-
- void (*dirty_inode) (struct inode *, int flags);
- int (*write_inode) (struct inode *, int);
- void (*drop_inode) (struct inode *);
- void (*delete_inode) (struct inode *);
- void (*put_super) (struct super_block *);
- int (*sync_fs)(struct super_block *sb, int wait);
- int (*freeze_fs) (struct super_block *);
- int (*unfreeze_fs) (struct super_block *);
- int (*statfs) (struct dentry *, struct kstatfs *);
- int (*remount_fs) (struct super_block *, int *, char *);
- void (*clear_inode) (struct inode *);
- void (*umount_begin) (struct super_block *);
-
- int (*show_options)(struct seq_file *, struct dentry *);
-
- ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
- ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
+ struct inode *(*alloc_inode)(struct super_block *sb);
+ void (*destroy_inode)(struct inode *);
+
+ void (*dirty_inode) (struct inode *, int flags);
+ int (*write_inode) (struct inode *, int);
+ void (*drop_inode) (struct inode *);
+ void (*delete_inode) (struct inode *);
+ void (*put_super) (struct super_block *);
+ int (*sync_fs)(struct super_block *sb, int wait);
+ int (*freeze_fs) (struct super_block *);
+ int (*unfreeze_fs) (struct super_block *);
+ int (*statfs) (struct dentry *, struct kstatfs *);
+ int (*remount_fs) (struct super_block *, int *, char *);
+ void (*clear_inode) (struct inode *);
+ void (*umount_begin) (struct super_block *);
+
+ int (*show_options)(struct seq_file *, struct dentry *);
+
+ ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
+ ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
int (*nr_cached_objects)(struct super_block *);
void (*free_cached_objects)(struct super_block *, int);
};
filesystem.
May be called in rcu-walk mode (mask & MAY_NOT_BLOCK). If in rcu-walk
- mode, the filesystem must check the permission without blocking or
+ mode, the filesystem must check the permission without blocking or
storing to the inode.
If a situation is encountered that rcu-walk cannot handle, return
tagged as DIRTY and will pass them to ->writepage.
set_page_dirty: called by the VM to set a page dirty.
- This is particularly needed if an address space attaches
- private data to a page, and that data needs to be updated when
- a page is dirtied. This is called, for example, when a memory
+ This is particularly needed if an address space attaches
+ private data to a page, and that data needs to be updated when
+ a page is dirtied. This is called, for example, when a memory
mapped page gets modified.
If defined, it should set the PageDirty flag, and the
- PAGECACHE_TAG_DIRTY tag in the radix tree.
+ PAGECACHE_TAG_DIRTY tag in the radix tree.
readpages: called by the VM to read pages associated with the address_space
object. This is essentially just a vector version of
storage, then those blocks should be pre-read (if they haven't been
read already) so that the updated blocks can be written out properly.
- The filesystem must return the locked pagecache page for the specified
+ The filesystem must return the locked pagecache page for the specified
offset, in *pagep, for the caller to write into.
It must be able to cope with short writes (where the length passed to
flags is a field for AOP_FLAG_xxx flags, described in
include/linux/fs.h.
- A void * may be returned in fsdata, which then gets passed into
- write_end.
+ A void * may be returned in fsdata, which then gets passed into
+ write_end.
- Returns 0 on success; < 0 on failure (which is the error code), in
+ Returns 0 on success; < 0 on failure (which is the error code), in
which case write_end is not called.
write_end: After a successful write_begin, and data copy, write_end must
- be called. len is the original len passed to write_begin, and copied
- is the amount that was able to be copied.
+ be called. len is the original len passed to write_begin, and copied
+ is the amount that was able to be copied.
- The filesystem must take care of unlocking the page and releasing it
- refcount, and updating i_size.
+ The filesystem must take care of unlocking the page and releasing it
+ refcount, and updating i_size.
- Returns < 0 on failure, otherwise the number of bytes (<= 'copied')
- that were able to be copied into pagecache.
+ Returns < 0 on failure, otherwise the number of bytes (<= 'copied')
+ that were able to be copied into pagecache.
bmap: called by the VFS to map a logical block offset within object to
physical block number. This method is used by the FIBMAP
are and uses those addresses directly.
invalidatepage: If a page has PagePrivate set, then invalidatepage
- will be called when part or all of the page is to be removed
+ will be called when part or all of the page is to be removed
from the address space. This generally corresponds to either a
truncation, punch hole or a complete invalidation of the address
space (in the latter case 'offset' will always be 0 and 'length'
release MUST succeed.
releasepage: releasepage is called on PagePrivate pages to indicate
- that the page should be freed if possible. ->releasepage
- should remove any private data from the page and clear the
- PagePrivate flag. If releasepage() fails for some reason, it must
+ that the page should be freed if possible. ->releasepage
+ should remove any private data from the page and clear the
+ PagePrivate flag. If releasepage() fails for some reason, it must
indicate failure with a 0 return value.
releasepage() is used in two distinct though related cases. The
first is when the VM finds a clean page with no active users and
- wants to make it a free page. If ->releasepage succeeds, the
- page will be removed from the address_space and become free.
+ wants to make it a free page. If ->releasepage succeeds, the
+ page will be removed from the address_space and become free.
The second case is when a request has been made to invalidate
- some or all pages in an address_space. This can happen
- through the fadvise(POSIX_FADV_DONTNEED) system call or by the
- filesystem explicitly requesting it as nfs and 9fs do (when
- they believe the cache may be out of date with storage) by
- calling invalidate_inode_pages2().
+ some or all pages in an address_space. This can happen
+ through the fadvise(POSIX_FADV_DONTNEED) system call or by the
+ filesystem explicitly requesting it as nfs and 9fs do (when
+ they believe the cache may be out of date with storage) by
+ calling invalidate_inode_pages2().
If the filesystem makes such a call, and needs to be certain
- that all pages are invalidated, then its releasepage will
- need to ensure this. Possibly it can clear the PageUptodate
- bit if it cannot free private data yet.
+ that all pages are invalidated, then its releasepage will
+ need to ensure this. Possibly it can clear the PageUptodate
+ bit if it cannot free private data yet.
freepage: freepage is called once the page is no longer visible in
- the page cache in order to allow the cleanup of any private
+ the page cache in order to allow the cleanup of any private
data. Since it may be called by the memory reclaimer, it
should not assume that the original address_space mapping still
exists, and it should not block.
direct_IO: called by the generic read/write routines to perform
- direct_IO - that is IO requests which bypass the page cache
- and transfer data directly between the storage and the
- application's address space.
+ direct_IO - that is IO requests which bypass the page cache
+ and transfer data directly between the storage and the
+ application's address space.
isolate_page: Called by the VM when isolating a movable non-lru page.
If page is successfully isolated, VM marks the page as PG_isolated
via __SetPageIsolated.
migrate_page: This is used to compact the physical memory usage.
- If the VM wants to relocate a page (maybe off a memory card
- that is signalling imminent failure) it will pass a new page
+ If the VM wants to relocate a page (maybe off a memory card
+ that is signalling imminent failure) it will pass a new page
and an old page to this function. migrate_page should
transfer any private data across and update any references
- that it has to the page.
+ that it has to the page.
putback_page: Called by the VM when isolated page's migration fails.
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