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-rw-r--r--Documentation/filesystems/Locking38
1 files changed, 19 insertions, 19 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 619af9bfdcb3..d30fb2cb5066 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -12,14 +12,17 @@ prototypes:
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 *, const struct dentry *,
+ int (*d_compare)(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,
@@ -194,8 +196,10 @@ prototypes:
void (*invalidatepage) (struct page *, unsigned int, unsigned int);
int (*releasepage) (struct page *, int);
void (*freepage)(struct page *);
- int (*direct_IO)(struct kiocb *, struct iov_iter *iter, loff_t offset);
+ 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
@@ -395,7 +395,7 @@ prototypes:
int (*release) (struct gendisk *, fmode_t);
int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
- int (*direct_access) (struct block_device *, sector_t, void __pmem **,
+ int (*direct_access) (struct block_device *, sector_t, void **,
unsigned long *);
int (*media_changed) (struct gendisk *);
void (*unlock_native_capacity) (struct gendisk *);
@@ -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