docs: filesystems: vfs: Convert spaces to tabs
There are bunch of places with 8 spaces, in preparation for correctly indenting all code snippets (during conversion to RST) change these to use tabspaces. This patch is whitespace only. Convert instances of 8 consecutive spaces to a single tabspace. Signed-off-by: Tobin C. Harding <tobin@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Tobin C. Harding
Jonathan Corbet
parent
e66b045715
commit
1b44ae63de
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@ -111,12 +111,12 @@ members are defined:
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struct file_system_type {
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struct file_system_type {
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const char *name;
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const char *name;
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int fs_flags;
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int fs_flags;
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struct dentry *(*mount) (struct file_system_type *, int,
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struct dentry *(*mount) (struct file_system_type *, int,
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const char *, void *);
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const char *, void *);
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void (*kill_sb) (struct super_block *);
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void (*kill_sb) (struct super_block *);
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struct module *owner;
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struct module *owner;
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struct file_system_type * next;
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struct file_system_type * next;
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struct list_head fs_supers;
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struct list_head fs_supers;
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struct lock_class_key s_lock_key;
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struct lock_class_key s_lock_key;
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struct lock_class_key s_umount_key;
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struct lock_class_key s_umount_key;
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};
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};
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@ -205,26 +205,26 @@ This describes how the VFS can manipulate the superblock of your
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filesystem. As of kernel 2.6.22, the following members are defined:
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filesystem. As of kernel 2.6.22, the following members are defined:
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struct super_operations {
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struct super_operations {
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struct inode *(*alloc_inode)(struct super_block *sb);
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struct inode *(*alloc_inode)(struct super_block *sb);
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void (*destroy_inode)(struct inode *);
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void (*destroy_inode)(struct inode *);
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void (*dirty_inode) (struct inode *, int flags);
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void (*dirty_inode) (struct inode *, int flags);
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int (*write_inode) (struct inode *, int);
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int (*write_inode) (struct inode *, int);
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void (*drop_inode) (struct inode *);
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void (*drop_inode) (struct inode *);
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void (*delete_inode) (struct inode *);
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void (*delete_inode) (struct inode *);
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void (*put_super) (struct super_block *);
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void (*put_super) (struct super_block *);
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int (*sync_fs)(struct super_block *sb, int wait);
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int (*sync_fs)(struct super_block *sb, int wait);
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int (*freeze_fs) (struct super_block *);
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int (*freeze_fs) (struct super_block *);
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int (*unfreeze_fs) (struct super_block *);
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int (*unfreeze_fs) (struct super_block *);
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int (*statfs) (struct dentry *, struct kstatfs *);
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int (*statfs) (struct dentry *, struct kstatfs *);
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int (*remount_fs) (struct super_block *, int *, char *);
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int (*remount_fs) (struct super_block *, int *, char *);
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void (*clear_inode) (struct inode *);
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void (*clear_inode) (struct inode *);
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void (*umount_begin) (struct super_block *);
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void (*umount_begin) (struct super_block *);
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int (*show_options)(struct seq_file *, struct dentry *);
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int (*show_options)(struct seq_file *, struct dentry *);
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ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
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ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
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ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
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ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
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int (*nr_cached_objects)(struct super_block *);
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int (*nr_cached_objects)(struct super_block *);
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void (*free_cached_objects)(struct super_block *, int);
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void (*free_cached_objects)(struct super_block *, int);
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};
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};
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@ -479,7 +479,7 @@ otherwise noted.
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filesystem.
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filesystem.
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May be called in rcu-walk mode (mask & MAY_NOT_BLOCK). If in rcu-walk
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May be called in rcu-walk mode (mask & MAY_NOT_BLOCK). If in rcu-walk
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mode, the filesystem must check the permission without blocking or
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mode, the filesystem must check the permission without blocking or
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storing to the inode.
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storing to the inode.
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If a situation is encountered that rcu-walk cannot handle, return
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If a situation is encountered that rcu-walk cannot handle, return
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@ -698,12 +698,12 @@ struct address_space_operations {
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tagged as DIRTY and will pass them to ->writepage.
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tagged as DIRTY and will pass them to ->writepage.
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set_page_dirty: called by the VM to set a page dirty.
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set_page_dirty: called by the VM to set a page dirty.
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This is particularly needed if an address space attaches
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This is particularly needed if an address space attaches
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private data to a page, and that data needs to be updated when
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private data to a page, and that data needs to be updated when
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a page is dirtied. This is called, for example, when a memory
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a page is dirtied. This is called, for example, when a memory
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mapped page gets modified.
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mapped page gets modified.
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If defined, it should set the PageDirty flag, and the
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If defined, it should set the PageDirty flag, and the
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PAGECACHE_TAG_DIRTY tag in the radix tree.
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PAGECACHE_TAG_DIRTY tag in the radix tree.
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readpages: called by the VM to read pages associated with the address_space
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readpages: called by the VM to read pages associated with the address_space
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object. This is essentially just a vector version of
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object. This is essentially just a vector version of
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@ -721,7 +721,7 @@ struct address_space_operations {
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storage, then those blocks should be pre-read (if they haven't been
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storage, then those blocks should be pre-read (if they haven't been
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read already) so that the updated blocks can be written out properly.
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read already) so that the updated blocks can be written out properly.
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The filesystem must return the locked pagecache page for the specified
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The filesystem must return the locked pagecache page for the specified
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offset, in *pagep, for the caller to write into.
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offset, in *pagep, for the caller to write into.
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It must be able to cope with short writes (where the length passed to
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It must be able to cope with short writes (where the length passed to
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@ -730,21 +730,21 @@ struct address_space_operations {
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flags is a field for AOP_FLAG_xxx flags, described in
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flags is a field for AOP_FLAG_xxx flags, described in
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include/linux/fs.h.
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include/linux/fs.h.
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A void * may be returned in fsdata, which then gets passed into
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A void * may be returned in fsdata, which then gets passed into
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write_end.
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write_end.
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Returns 0 on success; < 0 on failure (which is the error code), in
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Returns 0 on success; < 0 on failure (which is the error code), in
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which case write_end is not called.
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which case write_end is not called.
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write_end: After a successful write_begin, and data copy, write_end must
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write_end: After a successful write_begin, and data copy, write_end must
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be called. len is the original len passed to write_begin, and copied
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be called. len is the original len passed to write_begin, and copied
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is the amount that was able to be copied.
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is the amount that was able to be copied.
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The filesystem must take care of unlocking the page and releasing it
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The filesystem must take care of unlocking the page and releasing it
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refcount, and updating i_size.
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refcount, and updating i_size.
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Returns < 0 on failure, otherwise the number of bytes (<= 'copied')
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Returns < 0 on failure, otherwise the number of bytes (<= 'copied')
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that were able to be copied into pagecache.
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that were able to be copied into pagecache.
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bmap: called by the VFS to map a logical block offset within object to
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bmap: called by the VFS to map a logical block offset within object to
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physical block number. This method is used by the FIBMAP
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physical block number. This method is used by the FIBMAP
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@ -755,7 +755,7 @@ struct address_space_operations {
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are and uses those addresses directly.
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are and uses those addresses directly.
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invalidatepage: If a page has PagePrivate set, then invalidatepage
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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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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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from the address space. This generally corresponds to either a
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truncation, punch hole or a complete invalidation of the address
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truncation, punch hole or a complete invalidation of the address
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space (in the latter case 'offset' will always be 0 and 'length'
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space (in the latter case 'offset' will always be 0 and 'length'
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@ -767,47 +767,47 @@ struct address_space_operations {
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release MUST succeed.
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release MUST succeed.
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releasepage: releasepage is called on PagePrivate pages to indicate
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releasepage: releasepage is called on PagePrivate pages to indicate
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that the page should be freed if possible. ->releasepage
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that the page should be freed if possible. ->releasepage
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should remove any private data from the page and clear the
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should remove any private data from the page and clear the
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PagePrivate flag. If releasepage() fails for some reason, it must
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PagePrivate flag. If releasepage() fails for some reason, it must
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indicate failure with a 0 return value.
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indicate failure with a 0 return value.
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releasepage() is used in two distinct though related cases. The
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releasepage() is used in two distinct though related cases. The
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first is when the VM finds a clean page with no active users and
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first is when the VM finds a clean page with no active users and
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wants to make it a free page. If ->releasepage succeeds, the
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wants to make it a free page. If ->releasepage succeeds, the
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page will be removed from the address_space and become free.
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page will be removed from the address_space and become free.
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The second case is when a request has been made to invalidate
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The second case is when a request has been made to invalidate
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some or all pages in an address_space. This can happen
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some or all pages in an address_space. This can happen
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through the fadvise(POSIX_FADV_DONTNEED) system call or by the
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through the fadvise(POSIX_FADV_DONTNEED) system call or by the
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filesystem explicitly requesting it as nfs and 9fs do (when
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filesystem explicitly requesting it as nfs and 9fs do (when
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they believe the cache may be out of date with storage) by
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they believe the cache may be out of date with storage) by
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calling invalidate_inode_pages2().
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calling invalidate_inode_pages2().
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If the filesystem makes such a call, and needs to be certain
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If the filesystem makes such a call, and needs to be certain
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that all pages are invalidated, then its releasepage will
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that all pages are invalidated, then its releasepage will
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need to ensure this. Possibly it can clear the PageUptodate
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need to ensure this. Possibly it can clear the PageUptodate
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bit if it cannot free private data yet.
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bit if it cannot free private data yet.
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freepage: freepage is called once the page is no longer visible in
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freepage: freepage is called once the page is no longer visible in
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the page cache in order to allow the cleanup of any private
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the page cache in order to allow the cleanup of any private
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data. Since it may be called by the memory reclaimer, it
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data. Since it may be called by the memory reclaimer, it
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should not assume that the original address_space mapping still
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should not assume that the original address_space mapping still
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exists, and it should not block.
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exists, and it should not block.
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direct_IO: called by the generic read/write routines to perform
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direct_IO: called by the generic read/write routines to perform
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direct_IO - that is IO requests which bypass the page cache
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direct_IO - that is IO requests which bypass the page cache
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and transfer data directly between the storage and the
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and transfer data directly between the storage and the
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application's address space.
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application's address space.
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isolate_page: Called by the VM when isolating a movable non-lru page.
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isolate_page: Called by the VM when isolating a movable non-lru page.
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If page is successfully isolated, VM marks the page as PG_isolated
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If page is successfully isolated, VM marks the page as PG_isolated
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via __SetPageIsolated.
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via __SetPageIsolated.
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migrate_page: This is used to compact the physical memory usage.
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migrate_page: This is used to compact the physical memory usage.
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If the VM wants to relocate a page (maybe off a memory card
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If the VM wants to relocate a page (maybe off a memory card
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that is signalling imminent failure) it will pass a new page
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that is signalling imminent failure) it will pass a new page
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and an old page to this function. migrate_page should
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and an old page to this function. migrate_page should
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transfer any private data across and update any references
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transfer any private data across and update any references
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that it has to the page.
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that it has to the page.
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putback_page: Called by the VM when isolated page's migration fails.
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putback_page: Called by the VM when isolated page's migration fails.
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