[PATCH] tmpfs 1/9 shmem_vm_writeback

• Next message: Hugh Dickins: "[PATCH] tmpfs 2/9 partial shmem_holdpage"
• Previous message: J.A. Magallon: "Re: UFS filesystem"
• Next in thread: Hugh Dickins: "[PATCH] tmpfs 2/9 partial shmem_holdpage"
• Reply: Hugh Dickins: "[PATCH] tmpfs 2/9 partial shmem_holdpage"
• Reply: Hugh Dickins: "[PATCH] tmpfs 3/9 remove info->sem"
• Reply: Hugh Dickins: "[PATCH] tmpfs 4/9 shmem_getpage locked"
• Reply: Hugh Dickins: "[PATCH] tmpfs 5/9 shmem_free_block alloced"
• Reply: Hugh Dickins: "[PATCH] tmpfs 6/9 highmem metadata"
• Reply: Hugh Dickins: "[PATCH] tmpfs 7/9 shmem_swp_set nr_swapped"
• Reply: Hugh Dickins: "[PATCH] tmpfs 8/9 misc trivia"
• Reply: Hugh Dickins: "[PATCH] tmpfs 9/9 whitespace only"
• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

First of nine tmpfs patches, equivalent to (but aesthetic differences
from) what I sent wli a few days ago: starting from 2.5.40-mm1 base.

Diffstat for the whole lot:
 include/linux/shmem_fs.h | 6
 mm/shmem.c | 1269 ++++++++++++++++++++++++++---------------------
 2 files changed, 726 insertions(+), 549 deletions(-)

This is not the end of tmpfs mods for 2.5: I should have six or seven
more patches to come (including loopable unless loop.c does it first);
but let's publish these before they go stale. I know a swap_free goes
missing occasionally, before and after these patches: I wanted to sort
that out before sending these, but it's elusive so far: tests running.

tmpfs 1/9 shmem_vm_writeback

Give tmpfs its own shmem_vm_writeback (and empty shmem_writepages):
going through the default mpage_writepages is very wrong for tmpfs,
since that may write nearby pages while still mapped into mms, but
"writing" converts pages from tmpfs file identity to swap backing
identity: doing so while mapped breaks assumptions throughout e.g.
the shared file is liable to disintegrate into private instances.

--- 2.5.40-mm1/mm/shmem.c Tue Oct 1 15:35:33 2002
+++ tmpfs1/mm/shmem.c Tue Oct 1 19:48:54 2002
@@ -515,9 +515,8 @@
 
         if (!PageLocked(page))
                 BUG();
-
- if (!(current->flags & PF_MEMALLOC))
- return fail_writepage(page);
+ if (page_mapped(page))
+ BUG();
 
         mapping = page->mapping;
         index = page->index;
@@ -551,6 +550,19 @@
         return fail_writepage(page);
 }
 
+static int shmem_writepages(struct address_space *mapping, struct writeback_control *wbc)
+{
+ return 0;
+}
+
+static int shmem_vm_writeback(struct page *page, struct writeback_control *wbc)
+{
+ clear_page_dirty(page);
+ if (shmem_writepage(page) < 0)
+ set_page_dirty(page);
+ return 0;
+}
+
 /*
  * shmem_getpage_locked - either get the page from swap or allocate a new one
  *
@@ -1524,6 +1536,8 @@
 
 static struct address_space_operations shmem_aops = {
         .writepage = shmem_writepage,
+ .writepages = shmem_writepages,
+ .vm_writeback = shmem_vm_writeback,
         .set_page_dirty = __set_page_dirty_nobuffers,
 };
 

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

• Next message: Hugh Dickins: "[PATCH] tmpfs 2/9 partial shmem_holdpage"
• Previous message: J.A. Magallon: "Re: UFS filesystem"
• Next in thread: Hugh Dickins: "[PATCH] tmpfs 2/9 partial shmem_holdpage"
• Reply: Hugh Dickins: "[PATCH] tmpfs 2/9 partial shmem_holdpage"
• Reply: Hugh Dickins: "[PATCH] tmpfs 3/9 remove info->sem"
• Reply: Hugh Dickins: "[PATCH] tmpfs 4/9 shmem_getpage locked"
• Reply: Hugh Dickins: "[PATCH] tmpfs 5/9 shmem_free_block alloced"
• Reply: Hugh Dickins: "[PATCH] tmpfs 6/9 highmem metadata"
• Reply: Hugh Dickins: "[PATCH] tmpfs 7/9 shmem_swp_set nr_swapped"
• Reply: Hugh Dickins: "[PATCH] tmpfs 8/9 misc trivia"
• Reply: Hugh Dickins: "[PATCH] tmpfs 9/9 whitespace only"
• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

This archive was generated by hypermail 2b29 : Mon Oct 07 2002 - 22:00:28 EST