Gitweb:
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=ed2f2f9b3ff8debdf512f7687b232c3c1d7d60d7
Commit: ed2f2f9b3ff8debdf512f7687b232c3c1d7d60d7
Parent: 6967614761fd305b3414d9485d89dc2e0a407410
Author: Mark Fasheh <[EMAIL PROTECTED]>
AuthorDate: Thu Jul 19 01:47:01 2007 -0700
Committer: Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Thu Jul 19 10:04:41 2007 -0700
Document ->page_mkwrite() locking
There seems to be very little documentation about this callback in general.
The locking in particular is a bit tricky, so it's worth having this in
writing.
Signed-off-by: Mark Fasheh <[EMAIL PROTECTED]>
Cc: Nick Piggin <[EMAIL PROTECTED]>
Cc: David Howells <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
Documentation/filesystems/Locking | 11 ++++++++++-
1 files changed, 10 insertions(+), 1 deletions(-)
diff --git a/Documentation/filesystems/Locking
b/Documentation/filesystems/Locking
index 970c8ec..91ec4b4 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -512,13 +512,22 @@ prototypes:
void (*close)(struct vm_area_struct*);
struct page *(*fault)(struct vm_area_struct*, struct fault_data *);
struct page *(*nopage)(struct vm_area_struct*, unsigned long, int *);
+ int (*page_mkwrite)(struct vm_area_struct *, struct page *);
locking rules:
- BKL mmap_sem
+ BKL mmap_sem PageLocked(page)
open: no yes
close: no yes
fault: no yes
nopage: no yes
+page_mkwrite: no yes no
+
+ ->page_mkwrite() is called when a previously read-only page is
+about to become writeable. The file system is responsible for
+protecting against truncate races. Once appropriate action has been
+taking to lock out truncate, the page range should be verified to be
+within i_size. The page mapping should also be checked that it is not
+NULL.
================================================================================
Dubious stuff
-
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
