| Message ID | 20190318231437.1666-10-tobin@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Convert vfs.txt to vfs.rst | expand |
On Tue, Mar 19, 2019 at 10:14:33AM +1100, Tobin C. Harding wrote: > Use code-block for C source code. With this in place we can rename the > .txt file to .rst. This introduces a few warnings that will be fixed > in proceeding patches. > > Add '.. code-block:: c' to C source code snippets. Rename the file to > use rst file suffix. I just realised that a better way to document these structs is to do so above the actual struct definition in the source file then include those docs in the documentation file. I'm working on that now, I can do it on top of this or we can drop this and I can do it all as a v3. No further comments below, leaving for reference. thanks, Tobin. > Tested-by: Randy Dunlap <rdunlap@infradead.org> > Signed-off-by: Tobin C. Harding <tobin@kernel.org> > --- > > This ones a punish to review. It fixes up spacing around the struct > definitions. In hindsight this may not be what we want because now the > docs do not _exactly_ mirror the code. If this goes through update to > vfs.rst aims to patch the code first then update vfs.rst :) > > Documentation/filesystems/index.rst | 1 + > .../filesystems/{vfs.txt => vfs.rst} | 321 +++++++++--------- > 2 files changed, 169 insertions(+), 153 deletions(-) > rename Documentation/filesystems/{vfs.txt => vfs.rst} (86%) > > diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst > index 1131c34d77f6..35644840a690 100644 > --- a/Documentation/filesystems/index.rst > +++ b/Documentation/filesystems/index.rst > @@ -16,6 +16,7 @@ algorithms work. > .. toctree:: > :maxdepth: 2 > > + vfs > path-lookup.rst > api-summary > splice > diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.rst > similarity index 86% > rename from Documentation/filesystems/vfs.txt > rename to Documentation/filesystems/vfs.rst > index 6e709815a6dd..dc2dd81f5e83 100644 > --- a/Documentation/filesystems/vfs.txt > +++ b/Documentation/filesystems/vfs.rst > @@ -87,6 +87,8 @@ Registering and Mounting a Filesystem > To register and unregister a filesystem, use the following API > functions: > > +.. code-block:: c > + > #include <linux/fs.h> > > extern int register_filesystem(struct file_system_type *); > @@ -110,18 +112,19 @@ struct file_system_type > This describes the filesystem. As of kernel 2.6.39, the following > members are defined: > > -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 lock_class_key s_lock_key; > - struct lock_class_key s_umount_key; > -}; > +.. code-block:: c > + > + 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 lock_class_key s_lock_key; > + struct lock_class_key s_umount_key; > + }; > > - name: the name of the filesystem type, such as "ext2", "iso9660", > "msdos" and so on > @@ -206,30 +209,31 @@ struct super_operations > This describes how the VFS can manipulate the superblock of your > 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); > - int (*nr_cached_objects)(struct super_block *); > - void (*free_cached_objects)(struct super_block *, int); > -}; > +.. code-block:: c > + > + 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); > + int (*nr_cached_objects)(struct super_block *); > + void (*free_cached_objects)(struct super_block *, int); > + }; > > All methods are called without any locks being held, unless otherwise > noted. This means that most methods can block safely. All methods are > @@ -365,30 +369,32 @@ struct inode_operations > This describes how the VFS can manipulate an inode in your filesystem. > As of kernel 2.6.22, the following members are defined: > > -struct inode_operations { > - int (*create) (struct inode *,struct dentry *, umode_t, bool); > - struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int); > - int (*link) (struct dentry *,struct inode *,struct dentry *); > - int (*unlink) (struct inode *,struct dentry *); > - int (*symlink) (struct inode *,struct dentry *,const char *); > - int (*mkdir) (struct inode *,struct dentry *,umode_t); > - int (*rmdir) (struct inode *,struct dentry *); > - int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t); > - int (*rename) (struct inode *, struct dentry *, > - struct inode *, struct dentry *, unsigned int); > - int (*readlink) (struct dentry *, char __user *,int); > - const char *(*get_link) (struct dentry *, struct inode *, > - struct delayed_call *); > - int (*permission) (struct inode *, int); > - int (*get_acl)(struct inode *, int); > - int (*setattr) (struct dentry *, struct iattr *); > - int (*getattr) (const struct path *, struct kstat *, u32, unsigned int); > - ssize_t (*listxattr) (struct dentry *, char *, size_t); > - void (*update_time)(struct inode *, struct timespec *, int); > - int (*atomic_open)(struct inode *, struct dentry *, struct file *, > - unsigned open_flag, umode_t create_mode); > - int (*tmpfile) (struct inode *, struct dentry *, umode_t); > -}; > +.. code-block:: c > + > + struct inode_operations { > + int (*create) (struct inode *,struct dentry *, umode_t, bool); > + struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int); > + int (*link) (struct dentry *,struct inode *,struct dentry *); > + int (*unlink) (struct inode *,struct dentry *); > + int (*symlink) (struct inode *,struct dentry *,const char *); > + int (*mkdir) (struct inode *,struct dentry *,umode_t); > + int (*rmdir) (struct inode *,struct dentry *); > + int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t); > + int (*rename) (struct inode *, struct dentry *, > + struct inode *, struct dentry *, unsigned int); > + int (*readlink) (struct dentry *, char __user *,int); > + const char *(*get_link) (struct dentry *, struct inode *, > + struct delayed_call *); > + int (*permission) (struct inode *, int); > + int (*get_acl)(struct inode *, int); > + int (*setattr) (struct dentry *, struct iattr *); > + int (*getattr) (const struct path *, struct kstat *, u32, unsigned int); > + ssize_t (*listxattr) (struct dentry *, char *, size_t); > + void (*update_time)(struct inode *, struct timespec *, int); > + int (*atomic_open)(struct inode *, struct dentry *, struct file *, > + unsigned open_flag, umode_t create_mode); > + int (*tmpfile) (struct inode *, struct dentry *, umode_t); > + }; > > Again, all methods are called without any locks being held, unless > otherwise noted. > @@ -624,39 +630,41 @@ struct address_space_operations > This describes how the VFS can manipulate mapping of a file to page > cache in your filesystem. The following members are defined: > > -struct address_space_operations { > - int (*writepage)(struct page *page, struct writeback_control *wbc); > - int (*readpage)(struct file *, struct page *); > - int (*writepages)(struct address_space *, struct writeback_control *); > - int (*set_page_dirty)(struct page *page); > - int (*readpages)(struct file *filp, struct address_space *mapping, > - struct list_head *pages, unsigned nr_pages); > - int (*write_begin)(struct file *, struct address_space *mapping, > - loff_t pos, unsigned len, unsigned flags, > - struct page **pagep, void **fsdata); > - int (*write_end)(struct file *, struct address_space *mapping, > - loff_t pos, unsigned len, unsigned copied, > - struct page *page, void *fsdata); > - sector_t (*bmap)(struct address_space *, sector_t); > - void (*invalidatepage) (struct page *, unsigned int, unsigned int); > - int (*releasepage) (struct page *, int); > - void (*freepage)(struct page *); > - ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter); > - /* isolate a page for migration */ > - bool (*isolate_page) (struct page *, isolate_mode_t); > - /* migrate the contents of a page to the specified target */ > - int (*migratepage) (struct page *, struct page *); > - /* put migration-failed page back to right list */ > - void (*putback_page) (struct page *); > - int (*launder_page) (struct page *); > - > - int (*is_partially_uptodate) (struct page *, unsigned long, > - unsigned long); > - void (*is_dirty_writeback) (struct page *, bool *, bool *); > - int (*error_remove_page) (struct mapping *mapping, struct page *page); > - int (*swap_activate)(struct file *); > - int (*swap_deactivate)(struct file *); > -}; > +.. code-block:: c > + > + struct address_space_operations { > + int (*writepage)(struct page *page, struct writeback_control *wbc); > + int (*readpage)(struct file *, struct page *); > + int (*writepages)(struct address_space *, struct writeback_control *); > + int (*set_page_dirty)(struct page *page); > + int (*readpages)(struct file *filp, struct address_space *mapping, > + struct list_head *pages, unsigned nr_pages); > + int (*write_begin)(struct file *, struct address_space *mapping, > + loff_t pos, unsigned len, unsigned flags, > + struct page **pagep, void **fsdata); > + int (*write_end)(struct file *, struct address_space *mapping, > + loff_t pos, unsigned len, unsigned copied, > + struct page *page, void *fsdata); > + sector_t (*bmap)(struct address_space *, sector_t); > + void (*invalidatepage) (struct page *, unsigned int, unsigned int); > + int (*releasepage) (struct page *, int); > + void (*freepage)(struct page *); > + ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter); > + /* isolate a page for migration */ > + bool (*isolate_page) (struct page *, isolate_mode_t); > + /* migrate the contents of a page to the specified target */ > + int (*migratepage) (struct page *, struct page *); > + /* put migration-failed page back to right list */ > + void (*putback_page) (struct page *); > + int (*launder_page) (struct page *); > + > + int (*is_partially_uptodate) (struct page *, unsigned long, > + unsigned long); > + void (*is_dirty_writeback) (struct page *, bool *, bool *); > + int (*error_remove_page) (struct mapping *mapping, struct page *page); > + int (*swap_activate)(struct file *); > + int (*swap_deactivate)(struct file *); > + }; > > - writepage: called by the VM to write a dirty page to backing store. > This may happen for data integrity reasons (i.e. 'sync'), or > @@ -852,45 +860,50 @@ struct file_operations > This describes how the VFS can manipulate an open file. As of kernel > 4.18, 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 (*read_iter) (struct kiocb *, struct iov_iter *); > - ssize_t (*write_iter) (struct kiocb *, struct iov_iter *); > - int (*iopoll)(struct kiocb *kiocb, bool spin); > - int (*iterate) (struct file *, struct dir_context *); > - int (*iterate_shared) (struct file *, struct dir_context *); > - __poll_t (*poll) (struct file *, struct poll_table_struct *); > - 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 (*open) (struct inode *, 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 (*fasync) (int, struct file *, int); > - int (*lock) (struct file *, int, struct file_lock *); > - ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int); > - 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 *, 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 > - ssize_t (*copy_file_range)(struct file *, loff_t, struct file *, loff_t, size_t, unsigned int); > - loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in, > - struct file *file_out, loff_t pos_out, > - loff_t len, unsigned int remap_flags); > - int (*fadvise)(struct file *, loff_t, loff_t, int); > -}; > +.. code-block:: c > + > + 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 (*read_iter) (struct kiocb *, struct iov_iter *); > + ssize_t (*write_iter) (struct kiocb *, struct iov_iter *); > + int (*iopoll)(struct kiocb *kiocb, bool spin); > + int (*iterate) (struct file *, struct dir_context *); > + int (*iterate_shared) (struct file *, struct dir_context *); > + __poll_t (*poll) (struct file *, struct poll_table_struct *); > + 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 (*open) (struct inode *, 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 (*fasync) (int, struct file *, int); > + int (*lock) (struct file *, int, struct file_lock *); > + ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int); > + 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 *, > + 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 > + ssize_t (*copy_file_range)(struct file *, loff_t, struct file *, loff_t, > + size_t, unsigned int); > + loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in, > + struct file *file_out, loff_t pos_out, > + loff_t len, unsigned int remap_flags); > + int (*fadvise)(struct file *, loff_t, loff_t, int); > + }; > > Again, all methods are called without any locks being held, unless > otherwise noted. > @@ -1006,21 +1019,23 @@ here. These methods may be set to NULL, as they are either optional or > the VFS uses a default. As of kernel 2.6.22, the following members are > defined: > > -struct dentry_operations { > - int (*d_revalidate)(struct dentry *, unsigned int); > - int (*d_weak_revalidate)(struct dentry *, unsigned int); > - int (*d_hash)(const struct dentry *, struct qstr *); > - int (*d_compare)(const struct dentry *, > - unsigned int, const char *, const struct qstr *); > - int (*d_delete)(const struct dentry *); > - int (*d_init)(struct dentry *); > - void (*d_release)(struct dentry *); > - void (*d_iput)(struct dentry *, struct inode *); > - char *(*d_dname)(struct dentry *, char *, int); > - struct vfsmount *(*d_automount)(struct path *); > - int (*d_manage)(const struct path *, bool); > - struct dentry *(*d_real)(struct dentry *, const struct inode *); > -}; > +.. code-block:: c > + > + struct dentry_operations { > + int (*d_revalidate)(struct dentry *, unsigned int); > + int (*d_weak_revalidate)(struct dentry *, unsigned int); > + int (*d_hash)(const struct dentry *, struct qstr *); > + int (*d_compare)(const struct dentry *, > + unsigned int, const char *, const struct qstr *); > + int (*d_delete)(const struct dentry *); > + int (*d_init)(struct dentry *); > + void (*d_release)(struct dentry *); > + void (*d_iput)(struct dentry *, struct inode *); > + char *(*d_dname)(struct dentry *, char *, int); > + struct vfsmount *(*d_automount)(struct path *); > + int (*d_manage)(const struct path *, bool); > + struct dentry *(*d_real)(struct dentry *, const struct inode *); > + }; > > - d_revalidate: called when the VFS needs to revalidate a dentry. This > is called whenever a name look-up finds a dentry in the > @@ -1106,13 +1121,13 @@ struct dentry_operations { > at the end of the buffer, and returns a pointer to the first char. > dynamic_dname() helper function is provided to take care of this. > > - Example : > + .. code-block:: c > > - static char *pipefs_dname(struct dentry *dent, char *buffer, int buflen) > - { > - return dynamic_dname(dentry, buffer, buflen, "pipe:[%lu]", > - dentry->d_inode->i_ino); > - } > + static char *pipefs_dname(struct dentry *dent, char *buffer, int buflen) > + { > + return dynamic_dname(dentry, buffer, buflen, "pipe:[%lu]", > + dentry->d_inode->i_ino); > + } > > - d_automount: called when an automount dentry is to be traversed (optional). > This should create a new VFS mount record and return the record to the > -- > 2.21.0 >
On Tue, Mar 19, 2019 at 12:35:26PM +1100, Tobin C. Harding wrote: > On Tue, Mar 19, 2019 at 10:14:33AM +1100, Tobin C. Harding wrote: > > Use code-block for C source code. With this in place we can rename the > > .txt file to .rst. This introduces a few warnings that will be fixed > > in proceeding patches. > > > > Add '.. code-block:: c' to C source code snippets. Rename the file to > > use rst file suffix. > > I just realised that a better way to document these structs is to do so > above the actual struct definition in the source file then include those > docs in the documentation file. Please either drop this set or only consider patches 1-8 for merge. I haven't worked out _exactly_ how to move the docs from Documentation/filesystems/vfs to the source code files but I've played with it enough now to feel it is possible and it is definitely better. Just have to massage Sphinx into agreeing with me. I thought the whole reason we have docstring comments is because we all agreed that docs close to code hove more chance of staying relevant. vfs.txt proves that nicely (docs in it from 2.6 for structs that are actively used and developed). Sorry for the noise, one day I'll work these things out _before_ sending the patches :) thanks, Tobin.
diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst index 1131c34d77f6..35644840a690 100644 --- a/Documentation/filesystems/index.rst +++ b/Documentation/filesystems/index.rst @@ -16,6 +16,7 @@ algorithms work. .. toctree:: :maxdepth: 2 + vfs path-lookup.rst api-summary splice diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.rst similarity index 86% rename from Documentation/filesystems/vfs.txt rename to Documentation/filesystems/vfs.rst index 6e709815a6dd..dc2dd81f5e83 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.rst @@ -87,6 +87,8 @@ Registering and Mounting a Filesystem To register and unregister a filesystem, use the following API functions: +.. code-block:: c + #include <linux/fs.h> extern int register_filesystem(struct file_system_type *); @@ -110,18 +112,19 @@ struct file_system_type This describes the filesystem. As of kernel 2.6.39, the following members are defined: -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 lock_class_key s_lock_key; - struct lock_class_key s_umount_key; -}; +.. code-block:: c + + 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 lock_class_key s_lock_key; + struct lock_class_key s_umount_key; + }; - name: the name of the filesystem type, such as "ext2", "iso9660", "msdos" and so on @@ -206,30 +209,31 @@ struct super_operations This describes how the VFS can manipulate the superblock of your 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); - int (*nr_cached_objects)(struct super_block *); - void (*free_cached_objects)(struct super_block *, int); -}; +.. code-block:: c + + 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); + int (*nr_cached_objects)(struct super_block *); + void (*free_cached_objects)(struct super_block *, int); + }; All methods are called without any locks being held, unless otherwise noted. This means that most methods can block safely. All methods are @@ -365,30 +369,32 @@ struct inode_operations This describes how the VFS can manipulate an inode in your filesystem. As of kernel 2.6.22, the following members are defined: -struct inode_operations { - int (*create) (struct inode *,struct dentry *, umode_t, bool); - struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int); - int (*link) (struct dentry *,struct inode *,struct dentry *); - int (*unlink) (struct inode *,struct dentry *); - int (*symlink) (struct inode *,struct dentry *,const char *); - int (*mkdir) (struct inode *,struct dentry *,umode_t); - int (*rmdir) (struct inode *,struct dentry *); - int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t); - int (*rename) (struct inode *, struct dentry *, - struct inode *, struct dentry *, unsigned int); - int (*readlink) (struct dentry *, char __user *,int); - const char *(*get_link) (struct dentry *, struct inode *, - struct delayed_call *); - int (*permission) (struct inode *, int); - int (*get_acl)(struct inode *, int); - int (*setattr) (struct dentry *, struct iattr *); - int (*getattr) (const struct path *, struct kstat *, u32, unsigned int); - ssize_t (*listxattr) (struct dentry *, char *, size_t); - void (*update_time)(struct inode *, struct timespec *, int); - int (*atomic_open)(struct inode *, struct dentry *, struct file *, - unsigned open_flag, umode_t create_mode); - int (*tmpfile) (struct inode *, struct dentry *, umode_t); -}; +.. code-block:: c + + struct inode_operations { + int (*create) (struct inode *,struct dentry *, umode_t, bool); + struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int); + int (*link) (struct dentry *,struct inode *,struct dentry *); + int (*unlink) (struct inode *,struct dentry *); + int (*symlink) (struct inode *,struct dentry *,const char *); + int (*mkdir) (struct inode *,struct dentry *,umode_t); + int (*rmdir) (struct inode *,struct dentry *); + int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t); + int (*rename) (struct inode *, struct dentry *, + struct inode *, struct dentry *, unsigned int); + int (*readlink) (struct dentry *, char __user *,int); + const char *(*get_link) (struct dentry *, struct inode *, + struct delayed_call *); + int (*permission) (struct inode *, int); + int (*get_acl)(struct inode *, int); + int (*setattr) (struct dentry *, struct iattr *); + int (*getattr) (const struct path *, struct kstat *, u32, unsigned int); + ssize_t (*listxattr) (struct dentry *, char *, size_t); + void (*update_time)(struct inode *, struct timespec *, int); + int (*atomic_open)(struct inode *, struct dentry *, struct file *, + unsigned open_flag, umode_t create_mode); + int (*tmpfile) (struct inode *, struct dentry *, umode_t); + }; Again, all methods are called without any locks being held, unless otherwise noted. @@ -624,39 +630,41 @@ struct address_space_operations This describes how the VFS can manipulate mapping of a file to page cache in your filesystem. The following members are defined: -struct address_space_operations { - int (*writepage)(struct page *page, struct writeback_control *wbc); - int (*readpage)(struct file *, struct page *); - int (*writepages)(struct address_space *, struct writeback_control *); - int (*set_page_dirty)(struct page *page); - int (*readpages)(struct file *filp, struct address_space *mapping, - struct list_head *pages, unsigned nr_pages); - int (*write_begin)(struct file *, struct address_space *mapping, - loff_t pos, unsigned len, unsigned flags, - struct page **pagep, void **fsdata); - int (*write_end)(struct file *, struct address_space *mapping, - loff_t pos, unsigned len, unsigned copied, - struct page *page, void *fsdata); - sector_t (*bmap)(struct address_space *, sector_t); - void (*invalidatepage) (struct page *, unsigned int, unsigned int); - int (*releasepage) (struct page *, int); - void (*freepage)(struct page *); - ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter); - /* isolate a page for migration */ - bool (*isolate_page) (struct page *, isolate_mode_t); - /* migrate the contents of a page to the specified target */ - int (*migratepage) (struct page *, struct page *); - /* put migration-failed page back to right list */ - void (*putback_page) (struct page *); - int (*launder_page) (struct page *); - - int (*is_partially_uptodate) (struct page *, unsigned long, - unsigned long); - void (*is_dirty_writeback) (struct page *, bool *, bool *); - int (*error_remove_page) (struct mapping *mapping, struct page *page); - int (*swap_activate)(struct file *); - int (*swap_deactivate)(struct file *); -}; +.. code-block:: c + + struct address_space_operations { + int (*writepage)(struct page *page, struct writeback_control *wbc); + int (*readpage)(struct file *, struct page *); + int (*writepages)(struct address_space *, struct writeback_control *); + int (*set_page_dirty)(struct page *page); + int (*readpages)(struct file *filp, struct address_space *mapping, + struct list_head *pages, unsigned nr_pages); + int (*write_begin)(struct file *, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata); + int (*write_end)(struct file *, struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata); + sector_t (*bmap)(struct address_space *, sector_t); + void (*invalidatepage) (struct page *, unsigned int, unsigned int); + int (*releasepage) (struct page *, int); + void (*freepage)(struct page *); + ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter); + /* isolate a page for migration */ + bool (*isolate_page) (struct page *, isolate_mode_t); + /* migrate the contents of a page to the specified target */ + int (*migratepage) (struct page *, struct page *); + /* put migration-failed page back to right list */ + void (*putback_page) (struct page *); + int (*launder_page) (struct page *); + + int (*is_partially_uptodate) (struct page *, unsigned long, + unsigned long); + void (*is_dirty_writeback) (struct page *, bool *, bool *); + int (*error_remove_page) (struct mapping *mapping, struct page *page); + int (*swap_activate)(struct file *); + int (*swap_deactivate)(struct file *); + }; - writepage: called by the VM to write a dirty page to backing store. This may happen for data integrity reasons (i.e. 'sync'), or @@ -852,45 +860,50 @@ struct file_operations This describes how the VFS can manipulate an open file. As of kernel 4.18, 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 (*read_iter) (struct kiocb *, struct iov_iter *); - ssize_t (*write_iter) (struct kiocb *, struct iov_iter *); - int (*iopoll)(struct kiocb *kiocb, bool spin); - int (*iterate) (struct file *, struct dir_context *); - int (*iterate_shared) (struct file *, struct dir_context *); - __poll_t (*poll) (struct file *, struct poll_table_struct *); - 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 (*open) (struct inode *, 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 (*fasync) (int, struct file *, int); - int (*lock) (struct file *, int, struct file_lock *); - ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int); - 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 *, 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 - ssize_t (*copy_file_range)(struct file *, loff_t, struct file *, loff_t, size_t, unsigned int); - loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in, - struct file *file_out, loff_t pos_out, - loff_t len, unsigned int remap_flags); - int (*fadvise)(struct file *, loff_t, loff_t, int); -}; +.. code-block:: c + + 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 (*read_iter) (struct kiocb *, struct iov_iter *); + ssize_t (*write_iter) (struct kiocb *, struct iov_iter *); + int (*iopoll)(struct kiocb *kiocb, bool spin); + int (*iterate) (struct file *, struct dir_context *); + int (*iterate_shared) (struct file *, struct dir_context *); + __poll_t (*poll) (struct file *, struct poll_table_struct *); + 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 (*open) (struct inode *, 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 (*fasync) (int, struct file *, int); + int (*lock) (struct file *, int, struct file_lock *); + ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int); + 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 *, + 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 + ssize_t (*copy_file_range)(struct file *, loff_t, struct file *, loff_t, + size_t, unsigned int); + loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in, + struct file *file_out, loff_t pos_out, + loff_t len, unsigned int remap_flags); + int (*fadvise)(struct file *, loff_t, loff_t, int); + }; Again, all methods are called without any locks being held, unless otherwise noted. @@ -1006,21 +1019,23 @@ here. These methods may be set to NULL, as they are either optional or the VFS uses a default. As of kernel 2.6.22, the following members are defined: -struct dentry_operations { - int (*d_revalidate)(struct dentry *, unsigned int); - int (*d_weak_revalidate)(struct dentry *, unsigned int); - int (*d_hash)(const struct dentry *, struct qstr *); - int (*d_compare)(const struct dentry *, - unsigned int, const char *, const struct qstr *); - int (*d_delete)(const struct dentry *); - int (*d_init)(struct dentry *); - void (*d_release)(struct dentry *); - void (*d_iput)(struct dentry *, struct inode *); - char *(*d_dname)(struct dentry *, char *, int); - struct vfsmount *(*d_automount)(struct path *); - int (*d_manage)(const struct path *, bool); - struct dentry *(*d_real)(struct dentry *, const struct inode *); -}; +.. code-block:: c + + struct dentry_operations { + int (*d_revalidate)(struct dentry *, unsigned int); + int (*d_weak_revalidate)(struct dentry *, unsigned int); + int (*d_hash)(const struct dentry *, struct qstr *); + int (*d_compare)(const struct dentry *, + unsigned int, const char *, const struct qstr *); + int (*d_delete)(const struct dentry *); + int (*d_init)(struct dentry *); + void (*d_release)(struct dentry *); + void (*d_iput)(struct dentry *, struct inode *); + char *(*d_dname)(struct dentry *, char *, int); + struct vfsmount *(*d_automount)(struct path *); + int (*d_manage)(const struct path *, bool); + struct dentry *(*d_real)(struct dentry *, const struct inode *); + }; - d_revalidate: called when the VFS needs to revalidate a dentry. This is called whenever a name look-up finds a dentry in the @@ -1106,13 +1121,13 @@ struct dentry_operations { at the end of the buffer, and returns a pointer to the first char. dynamic_dname() helper function is provided to take care of this. - Example : + .. code-block:: c - static char *pipefs_dname(struct dentry *dent, char *buffer, int buflen) - { - return dynamic_dname(dentry, buffer, buflen, "pipe:[%lu]", - dentry->d_inode->i_ino); - } + static char *pipefs_dname(struct dentry *dent, char *buffer, int buflen) + { + return dynamic_dname(dentry, buffer, buflen, "pipe:[%lu]", + dentry->d_inode->i_ino); + } - d_automount: called when an automount dentry is to be traversed (optional). This should create a new VFS mount record and return the record to the