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-rw-r--r--Documentation/filesystems/Locking18
1 files changed, 16 insertions, 2 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 5b0c083d7c0e..eba790134253 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -47,6 +47,8 @@ prototypes:
int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);
int (*rename) (struct inode *, struct dentry *,
struct inode *, struct dentry *);
+ int (*rename2) (struct inode *, struct dentry *,
+ struct inode *, struct dentry *, unsigned int);
int (*readlink) (struct dentry *, char __user *,int);
void * (*follow_link) (struct dentry *, struct nameidata *);
void (*put_link) (struct dentry *, struct nameidata *, void *);
@@ -78,6 +80,7 @@ mkdir: yes
unlink: yes (both)
rmdir: yes (both) (see below)
rename: yes (all) (see below)
+rename2: yes (all) (see below)
readlink: no
follow_link: no
put_link: no
@@ -96,7 +99,8 @@ tmpfile: no
Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on
victim.
- cross-directory ->rename() has (per-superblock) ->s_vfs_rename_sem.
+ cross-directory ->rename() and rename2() has (per-superblock)
+->s_vfs_rename_sem.
See Documentation/filesystems/directory-locking for more detailed discussion
of the locking scheme for directory operations.
@@ -198,7 +202,7 @@ prototypes:
unsigned long *);
int (*migratepage)(struct address_space *, struct page *, struct page *);
int (*launder_page)(struct page *);
- int (*is_partially_uptodate)(struct page *, read_descriptor_t *, unsigned long);
+ int (*is_partially_uptodate)(struct page *, unsigned long, unsigned long);
int (*error_remove_page)(struct address_space *, struct page *);
int (*swap_activate)(struct file *);
int (*swap_deactivate)(struct file *);
@@ -525,6 +529,7 @@ locking rules:
open: yes
close: yes
fault: yes can return with page locked
+map_pages: yes
page_mkwrite: yes can return with page locked
access: yes
@@ -536,6 +541,15 @@ the page, then ensure it is not already truncated (the page lock will block
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
+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_mkwrite() is called when a previously read-only pte is
about to become writeable. The filesystem again must ensure that there are
no truncate/invalidate races, and then return with the page locked. If