[kernel] r15747 - in dists/trunk/linux-2.6/debian: . patches/bugfix/all patches/series
Maximilian Attems
maks at alioth.debian.org
Tue May 18 14:24:36 UTC 2010
Author: maks
Date: Tue May 18 14:24:31 2010
New Revision: 15747
Log:
Explicitly pass in whether sb is pinned or not
fix famous Kees Cook bug,
patches are scheduled for 2.6.35-rc1 and will go into stable.
this is the first that fixes original issue.
Added:
dists/trunk/linux-2.6/debian/patches/bugfix/all/fs-explicitly-pass-in-whether-sb-is-pinned-or-not.patch
Modified:
dists/trunk/linux-2.6/debian/changelog
dists/trunk/linux-2.6/debian/patches/series/base
Modified: dists/trunk/linux-2.6/debian/changelog
==============================================================================
--- dists/trunk/linux-2.6/debian/changelog Tue May 18 14:23:01 2010 (r15746)
+++ dists/trunk/linux-2.6/debian/changelog Tue May 18 14:24:31 2010 (r15747)
@@ -20,6 +20,7 @@
* Fix backlight support on some recent Thinkpads.
* Enable autosuspend on UVC by default.
* acpi: Fall back to manually changing SCI_EN.
+ * Explicitly pass in whether sb is pinned or not.
[ Ben Hutchings ]
* Prepare debconf templates for translation (Closes: #576758)
Added: dists/trunk/linux-2.6/debian/patches/bugfix/all/fs-explicitly-pass-in-whether-sb-is-pinned-or-not.patch
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ dists/trunk/linux-2.6/debian/patches/bugfix/all/fs-explicitly-pass-in-whether-sb-is-pinned-or-not.patch Tue May 18 14:24:31 2010 (r15747)
@@ -0,0 +1,196 @@
+From: Jens Axboe <axboe at kernel.dk>
+Date: 2010-05-06 07:08:55
+Subject: Explicitly pass in whether sb is pinned or not
+
+
+Revision two of this patch. I got rid of WB_SYNC_NONE_PIN, since we should not
+further muddy the sync type and whether or not the sb is pinned. Instead lets
+add a specific flag for this.
+
+BZ: 15906, Launchpad: 543617
+
+diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
+index 4b37f7c..c9ac9cb 100644
+--- a/fs/fs-writeback.c
++++ b/fs/fs-writeback.c
+@@ -45,6 +45,7 @@ struct wb_writeback_args {
+ int for_kupdate:1;
+ int range_cyclic:1;
+ int for_background:1;
++ int sb_pinned:1;
+ };
+
+ /*
+@@ -230,6 +231,11 @@ static void bdi_sync_writeback(struct backing_dev_info *bdi,
+ .sync_mode = WB_SYNC_ALL,
+ .nr_pages = LONG_MAX,
+ .range_cyclic = 0,
++ /*
++ * Setting sb_pinned is not necessary for WB_SYNC_ALL, but
++ * lets make it explicitly clear.
++ */
++ .sb_pinned = 1,
+ };
+ struct bdi_work work;
+
+@@ -245,21 +251,23 @@ static void bdi_sync_writeback(struct backing_dev_info *bdi,
+ * @bdi: the backing device to write from
+ * @sb: write inodes from this super_block
+ * @nr_pages: the number of pages to write
++ * @sb_locked: caller already holds sb umount sem.
+ *
+ * Description:
+ * This does WB_SYNC_NONE opportunistic writeback. The IO is only
+ * started when this function returns, we make no guarentees on
+- * completion. Caller need not hold sb s_umount semaphore.
++ * completion. Caller specifies whether sb umount sem is held already or not.
+ *
+ */
+ void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb,
+- long nr_pages)
++ long nr_pages, int sb_locked)
+ {
+ struct wb_writeback_args args = {
+ .sb = sb,
+ .sync_mode = WB_SYNC_NONE,
+ .nr_pages = nr_pages,
+ .range_cyclic = 1,
++ .sb_pinned = sb_locked,
+ };
+
+ /*
+@@ -577,7 +585,7 @@ static enum sb_pin_state pin_sb_for_writeback(struct writeback_control *wbc,
+ /*
+ * Caller must already hold the ref for this
+ */
+- if (wbc->sync_mode == WB_SYNC_ALL) {
++ if (wbc->sync_mode == WB_SYNC_ALL || wbc->sb_pinned) {
+ WARN_ON(!rwsem_is_locked(&sb->s_umount));
+ return SB_NOT_PINNED;
+ }
+@@ -751,6 +759,7 @@ static long wb_writeback(struct bdi_writeback *wb,
+ .for_kupdate = args->for_kupdate,
+ .for_background = args->for_background,
+ .range_cyclic = args->range_cyclic,
++ .sb_pinned = args->sb_pinned,
+ };
+ unsigned long oldest_jif;
+ long wrote = 0;
+@@ -1183,6 +1192,18 @@ static void wait_sb_inodes(struct super_block *sb)
+ iput(old_inode);
+ }
+
++static void __writeback_inodes_sb(struct super_block *sb, int sb_locked)
++{
++ unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
++ unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS);
++ long nr_to_write;
++
++ nr_to_write = nr_dirty + nr_unstable +
++ (inodes_stat.nr_inodes - inodes_stat.nr_unused);
++
++ bdi_start_writeback(sb->s_bdi, sb, nr_to_write, sb_locked);
++}
++
+ /**
+ * writeback_inodes_sb - writeback dirty inodes from given super_block
+ * @sb: the superblock
+@@ -1194,18 +1215,23 @@ static void wait_sb_inodes(struct super_block *sb)
+ */
+ void writeback_inodes_sb(struct super_block *sb)
+ {
+- unsigned long nr_dirty = global_page_state(NR_FILE_DIRTY);
+- unsigned long nr_unstable = global_page_state(NR_UNSTABLE_NFS);
+- long nr_to_write;
+-
+- nr_to_write = nr_dirty + nr_unstable +
+- (inodes_stat.nr_inodes - inodes_stat.nr_unused);
+-
+- bdi_start_writeback(sb->s_bdi, sb, nr_to_write);
++ __writeback_inodes_sb(sb, 0);
+ }
+ EXPORT_SYMBOL(writeback_inodes_sb);
+
+ /**
++ * writeback_inodes_sb_locked - writeback dirty inodes from given super_block
++ * @sb: the superblock
++ *
++ * Like writeback_inodes_sb(), except the caller already holds the
++ * sb umount sem.
++ */
++void writeback_inodes_sb_locked(struct super_block *sb)
++{
++ __writeback_inodes_sb(sb, 1);
++}
++
++/**
+ * writeback_inodes_sb_if_idle - start writeback if none underway
+ * @sb: the superblock
+ *
+diff --git a/fs/sync.c b/fs/sync.c
+index 92b2281..de6a441 100644
+--- a/fs/sync.c
++++ b/fs/sync.c
+@@ -42,7 +42,7 @@ static int __sync_filesystem(struct super_block *sb, int wait)
+ if (wait)
+ sync_inodes_sb(sb);
+ else
+- writeback_inodes_sb(sb);
++ writeback_inodes_sb_locked(sb);
+
+ if (sb->s_op->sync_fs)
+ sb->s_op->sync_fs(sb, wait);
+diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
+index bd0e3c6..90e677a 100644
+--- a/include/linux/backing-dev.h
++++ b/include/linux/backing-dev.h
+@@ -103,7 +103,7 @@ int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev);
+ void bdi_unregister(struct backing_dev_info *bdi);
+ int bdi_setup_and_register(struct backing_dev_info *, char *, unsigned int);
+ void bdi_start_writeback(struct backing_dev_info *bdi, struct super_block *sb,
+- long nr_pages);
++ long nr_pages, int sb_locked);
+ int bdi_writeback_task(struct bdi_writeback *wb);
+ int bdi_has_dirty_io(struct backing_dev_info *bdi);
+
+diff --git a/include/linux/writeback.h b/include/linux/writeback.h
+index 36520de..3790165 100644
+--- a/include/linux/writeback.h
++++ b/include/linux/writeback.h
+@@ -65,6 +65,15 @@ struct writeback_control {
+ * so we use a single control to update them
+ */
+ unsigned no_nrwrite_index_update:1;
++
++ /*
++ * For WB_SYNC_ALL, the sb must always be pinned. For WB_SYNC_NONE,
++ * the writeback code will pin the sb for the caller. However,
++ * for eg umount, the caller does WB_SYNC_NONE but already has
++ * the sb pinned. If the below is set, caller already has the
++ * sb pinned.
++ */
++ unsigned sb_pinned:1;
+ };
+
+ /*
+@@ -73,6 +82,7 @@ struct writeback_control {
+ struct bdi_writeback;
+ int inode_wait(void *);
+ void writeback_inodes_sb(struct super_block *);
++void writeback_inodes_sb_locked(struct super_block *);
+ int writeback_inodes_sb_if_idle(struct super_block *);
+ void sync_inodes_sb(struct super_block *);
+ void writeback_inodes_wbc(struct writeback_control *wbc);
+diff --git a/mm/page-writeback.c b/mm/page-writeback.c
+index 0b19943..49d3508 100644
+--- a/mm/page-writeback.c
++++ b/mm/page-writeback.c
+@@ -597,7 +597,7 @@ static void balance_dirty_pages(struct address_space *mapping,
+ (!laptop_mode && ((global_page_state(NR_FILE_DIRTY)
+ + global_page_state(NR_UNSTABLE_NFS))
+ > background_thresh)))
+- bdi_start_writeback(bdi, NULL, 0);
++ bdi_start_writeback(bdi, NULL, 0, 0);
+ }
+
+ void set_page_dirty_balance(struct page *page, int page_mkwrite)
Modified: dists/trunk/linux-2.6/debian/patches/series/base
==============================================================================
--- dists/trunk/linux-2.6/debian/patches/series/base Tue May 18 14:23:01 2010 (r15746)
+++ dists/trunk/linux-2.6/debian/patches/series/base Tue May 18 14:24:31 2010 (r15747)
@@ -68,3 +68,4 @@
+ bugfix/all/thinkpad-acpi-fix-backlight.patch
+ bugfix/all/linux-2.6-usb-uvc-autosuspend.diff
+ bugfix/all/linux-2.6-acpi-sleep-live-sci-live.patch
++ bugfix/all/fs-explicitly-pass-in-whether-sb-is-pinned-or-not.patch
More information about the Kernel-svn-changes
mailing list