diff options
Diffstat (limited to 'Documentation/filesystems/Locking')
| -rw-r--r-- | Documentation/filesystems/Locking | 32 |
1 files changed, 16 insertions, 16 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index d9c37ec4c760..1b3c39a7de62 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -15,11 +15,14 @@ prototypes: int (*d_compare)(const struct dentry *, const struct dentry *, unsigned int, const char *, const struct qstr *); int (*d_delete)(struct dentry *); + int (*d_init)(struct dentry *); void (*d_release)(struct dentry *); void (*d_iput)(struct dentry *, struct inode *); char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen); struct vfsmount *(*d_automount)(struct path *path); int (*d_manage)(struct dentry *, bool); + struct dentry *(*d_real)(struct dentry *, const struct inode *, + unsigned int); locking rules: rename_lock ->d_lock may block rcu-walk @@ -28,12 +31,14 @@ d_weak_revalidate:no no yes no d_hash no no no maybe d_compare: yes no no maybe d_delete: no yes no no +d_init: no no yes no d_release: no no yes no d_prune: no yes no no d_iput: no no yes no d_dname: no no no no d_automount: no no yes no d_manage: no no yes (ref-walk) maybe +d_real no no yes no --------------------------- inode_operations --------------------------- prototypes: @@ -66,7 +71,6 @@ prototypes: struct file *, unsigned open_flag, umode_t create_mode, int *opened); int (*tmpfile) (struct inode *, struct dentry *, umode_t); - int (*dentry_open)(struct dentry *, struct file *, const struct cred *); locking rules: all may block @@ -95,7 +99,6 @@ fiemap: no update_time: no atomic_open: yes tmpfile: no -dentry_open: no Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on victim. @@ -179,7 +182,6 @@ unlocks and drops the reference. prototypes: int (*writepage)(struct page *page, struct writeback_control *wbc); int (*readpage)(struct file *, struct page *); - int (*sync_page)(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, @@ -195,7 +197,9 @@ prototypes: int (*releasepage) (struct page *, int); void (*freepage)(struct page *); int (*direct_IO)(struct kiocb *, struct iov_iter *iter); + bool (*isolate_page) (struct page *, isolate_mode_t); int (*migratepage)(struct address_space *, struct page *, struct page *); + void (*putback_page) (struct page *); int (*launder_page)(struct page *); int (*is_partially_uptodate)(struct page *, unsigned long, unsigned long); int (*error_remove_page)(struct address_space *, struct page *); @@ -208,7 +212,6 @@ locking rules: PageLocked(page) i_mutex writepage: yes, unlocks (see below) readpage: yes, unlocks -sync_page: maybe writepages: set_page_dirty no readpages: @@ -219,15 +222,17 @@ invalidatepage: yes releasepage: yes freepage: yes direct_IO: +isolate_page: yes migratepage: yes (both) +putback_page: yes launder_page: yes is_partially_uptodate: yes error_remove_page: yes swap_activate: no swap_deactivate: no - ->write_begin(), ->write_end(), ->sync_page() and ->readpage() -may be called from the request handler (/dev/loop). + ->write_begin(), ->write_end() and ->readpage() may be called from +the request handler (/dev/loop). ->readpage() unlocks the page, either synchronously or via I/O completion. @@ -283,11 +288,6 @@ will leave the page itself marked clean but it will be tagged as dirty in the radix tree. This incoherency can lead to all sorts of hard-to-debug problems in the filesystem like having dirty inodes at umount and losing written data. - ->sync_page() locking rules are not well-defined - usually it is called -with lock on page, but that is not guaranteed. Considering the currently -existing instances of this method ->sync_page() itself doesn't look -well-defined... - ->writepages() is used for periodic writeback and for syscall-initiated sync operations. The address_space should start I/O against at least *nr_to_write pages. *nr_to_write must be decremented for each page which is @@ -544,13 +544,13 @@ subsequent truncate), and then return with VM_FAULT_LOCKED, and the page locked. The VM will unlock the page. ->map_pages() is called when VM asks to map easy accessible pages. -Filesystem should find and map pages associated with offsets from "pgoff" -till "max_pgoff". ->map_pages() is called with page table locked and must +Filesystem should find and map pages associated with offsets from "start_pgoff" +till "end_pgoff". ->map_pages() is called with page table locked and must not block. If it's not possible to reach a page without blocking, filesystem should skip it. Filesystem should use do_set_pte() to setup -page table entry. Pointer to entry associated with offset "pgoff" is -passed in "pte" field in vm_fault structure. Pointers to entries for other -offsets should be calculated relative to "pte". +page table entry. Pointer to entry associated with the page is passed in +"pte" field in fault_env structure. Pointers to entries for other offsets +should be calculated relative to "pte". ->page_mkwrite() is called when a previously read-only pte is about to become writeable. The filesystem again must ensure that there are |