turn on barriers by default for ext3 and support barriers for single device DM devices

diff --git a/kernel-2.6.spec b/kernel-2.6.spec
index 3256654..e93c0cc 100644 (file)
--- a/kernel-2.6.spec
+++ b/kernel-2.6.spec
@@ -217,6 +217,9 @@ Patch800: linux-2.6-800-fix-4-bit-apicid-assumption.patch
 
 Patch810: linux-2.6-810-ich10.patch
 
+Patch900: linux-2.6-900-ext3_mount_default_to_barrier.patch
+Patch910: linux-2.6-910-support_barriers_on_single_device_dm_devices.patch
+
 # See also the file named 'sources' here for the related checksums
 # NOTE. iwlwifi should be in-kernel starting from 2.6.24
 # see http://bughost.org/bugzilla/show_bug.cgi?id=1584
@@ -454,6 +457,8 @@ KERNEL_PREVIOUS=vanilla
 %ApplyPatch 800
 %ApplyPatch 810
 
+%ApplyPatch 900
+%ApplyPatch 910
 
 # NetNS conflict-resolving patch for VINI. Will work with patch vini_pl_patch-1 but may
 # break with later patches.

diff --git a/linux-2.6-900-ext3_mount_default_to_barrier.patch b/linux-2.6-900-ext3_mount_default_to_barrier.patch
new file mode 100644 (file)
index 0000000..8a212ae
--- /dev/null
+++ b/linux-2.6-900-ext3_mount_default_to_barrier.patch
@@ -0,0 +1,42 @@
+commit 79eb79ed8e042e446accad244073af0f9bf4f35d
+Author: S.Çağlar Onur <caglar@cs.princeton.edu>
+Date:   Fri Mar 19 10:17:24 2010 -0400
+
+    make_ext3_mount_default_to_barrier=1
+
+diff --git a/fs/ext3/fsync.c b/fs/ext3/fsync.c
+index 00c9597..841f0f7 100644
+--- a/fs/ext3/fsync.c
++++ b/fs/ext3/fsync.c
+@@ -27,6 +27,7 @@
+ #include <linux/sched.h>
+ #include <linux/writeback.h>
+ #include <linux/jbd.h>
++#include <linux/blkdev.h>
+ #include <linux/ext3_fs.h>
+ #include <linux/ext3_jbd.h>
+ 
+@@ -84,7 +85,10 @@ int ext3_sync_file(struct file * file, struct dentry *dentry, int datasync)
+                       .sync_mode = WB_SYNC_ALL,
+                       .nr_to_write = 0, /* sys_fsync did this */
+               };
++              journal_t *journal = EXT3_SB(inode->i_sb)->s_journal;
+               ret = sync_inode(inode, &wbc);
++              if (journal && (journal->j_flags & JFS_BARRIER))
++                      blkdev_issue_flush(inode->i_sb->s_bdev, NULL);
+       }
+ out:
+       return ret;
+diff --git a/fs/ext3/super.c b/fs/ext3/super.c
+index 7facb78..ce186bc 100644
+--- a/fs/ext3/super.c
++++ b/fs/ext3/super.c
+@@ -1504,6 +1504,8 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
+       sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
+       sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
+ 
++      /* enable barriers by default */
++      set_opt(sbi->s_mount_opt, BARRIER);
+       set_opt(sbi->s_mount_opt, RESERVATION);
+ 
+       if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,

diff --git a/linux-2.6-910-support_barriers_on_single_device_dm_devices.patch b/linux-2.6-910-support_barriers_on_single_device_dm_devices.patch
new file mode 100644 (file)
index 0000000..dc14c83
--- /dev/null
+++ b/linux-2.6-910-support_barriers_on_single_device_dm_devices.patch
@@ -0,0 +1,160 @@
+commit 1327d9674e235b4c3004034298ba4863d038ee88
+Author: S.Çağlar Onur <caglar@cs.princeton.edu>
+Date:   Fri Mar 19 15:12:59 2010 -0400
+
+    support_barriers_on_single_device_dm_devices.patch
+
+diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
+index 17753d8..cda44f6 100644
+--- a/drivers/md/dm-linear.c
++++ b/drivers/md/dm-linear.c
+@@ -123,6 +123,7 @@ static struct target_type linear_target = {
+       .map    = linear_map,
+       .status = linear_status,
+       .ioctl  = linear_ioctl,
++      .features = DM_TARGET_SUPPORTS_BARRIERS,
+ };
+ 
+ int __init dm_linear_init(void)
+diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
+index 2fc199b..e540f57 100644
+--- a/drivers/md/dm-table.c
++++ b/drivers/md/dm-table.c
+@@ -38,6 +38,8 @@ struct dm_table {
+       sector_t *highs;
+       struct dm_target *targets;
+ 
++      unsigned barriers_supported:1;
++
+       /*
+        * Indicates the rw permissions for the new logical
+        * device.  This should be a combination of FMODE_READ
+@@ -221,6 +223,7 @@ int dm_table_create(struct dm_table **result, int mode,
+       memset(t, 0, sizeof(*t));
+       INIT_LIST_HEAD(&t->devices);
+       atomic_set(&t->holders, 1);
++      t->barriers_supported = 1;
+ 
+       if (!num_targets)
+               num_targets = KEYS_PER_NODE;
+@@ -765,6 +768,10 @@ int dm_table_add_target(struct dm_table *t, const char *type,
+       /* FIXME: the plan is to combine high here and then have
+        * the merge fn apply the target level restrictions. */
+       combine_restrictions_low(&t->limits, &tgt->limits);
++
++      if (!(tgt->type->features & DM_TARGET_SUPPORTS_BARRIERS))
++              t->barriers_supported = 0;
++
+       return 0;
+ 
+  bad:
+@@ -809,6 +816,12 @@ int dm_table_complete(struct dm_table *t)
+ 
+       check_for_valid_limits(&t->limits);
+ 
++      /*
++       * We only support barriers if there is exactly one underlying device.
++       */
++      if (!list_is_singular(&t->devices))
++              t->barriers_supported = 0;
++
+       /* how many indexes will the btree have ? */
+       leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
+       t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
+@@ -1033,6 +1046,11 @@ struct mapped_device *dm_table_get_md(struct dm_table *t)
+       return t->md;
+ }
+ 
++int dm_table_barrier_ok(struct dm_table *t)
++{
++      return t->barriers_supported;
++}
++EXPORT_SYMBOL(dm_table_barrier_ok);
+ EXPORT_SYMBOL(dm_vcalloc);
+ EXPORT_SYMBOL(dm_get_device);
+ EXPORT_SYMBOL(dm_put_device);
+diff --git a/drivers/md/dm.c b/drivers/md/dm.c
+index 12ecab3..bdf5107 100644
+--- a/drivers/md/dm.c
++++ b/drivers/md/dm.c
+@@ -781,6 +781,12 @@ static void __split_bio(struct mapped_device *md, struct bio *bio)
+               return;
+       }
+ 
++      if (unlikely(bio_barrier(bio) && !dm_table_barrier_ok(ci.map))) {
++              dm_table_put(ci.map);
++              bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
++              return;
++      }
++
+       ci.md = md;
+       ci.bio = bio;
+       ci.io = alloc_io(md);
+@@ -814,15 +820,6 @@ static int dm_request(request_queue_t *q, struct bio *bio)
+       int rw = bio_data_dir(bio);
+       struct mapped_device *md = q->queuedata;
+ 
+-      /*
+-       * There is no use in forwarding any barrier request since we can't
+-       * guarantee it is (or can be) handled by the targets correctly.
+-       */
+-      if (unlikely(bio_barrier(bio))) {
+-              bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
+-              return 0;
+-      }
+-
+       down_read(&md->io_lock);
+ 
+       disk_stat_inc(dm_disk(md), ios[rw]);
+diff --git a/drivers/md/dm.h b/drivers/md/dm.h
+index e71b22d..a67e8b7 100644
+--- a/drivers/md/dm.h
++++ b/drivers/md/dm.h
+@@ -80,6 +80,7 @@ int dm_table_resume_targets(struct dm_table *t);
+ int dm_table_any_congested(struct dm_table *t, int bdi_bits);
+ void dm_table_unplug_all(struct dm_table *t);
+ int dm_table_flush_all(struct dm_table *t);
++int dm_table_barrier_ok(struct dm_table *t);
+ 
+ /*-----------------------------------------------------------------
+  * A registry of target types.
+diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
+index 499f537..6bc9120 100644
+--- a/include/linux/device-mapper.h
++++ b/include/linux/device-mapper.h
+@@ -89,9 +89,15 @@ int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
+ void dm_put_device(struct dm_target *ti, struct dm_dev *d);
+ 
+ /*
++ * Target features
++ */
++#define DM_TARGET_SUPPORTS_BARRIERS 0x00000001
++
++/*
+  * Information about a target type
+  */
+ struct target_type {
++      uint64_t features;
+       const char *name;
+       struct module *module;
+       unsigned version[3];
+diff --git a/include/linux/list.h b/include/linux/list.h
+index f29fc9c..55051eb 100644
+--- a/include/linux/list.h
++++ b/include/linux/list.h
+@@ -319,6 +319,15 @@ static inline int list_empty_careful(const struct list_head *head)
+       return (next == head) && (next == head->prev);
+ }
+ 
++/**
++ * list_is_singular - tests whether a list has just one entry.
++ * @head: the list to test.
++ */
++static inline int list_is_singular(const struct list_head *head)
++{
++        return !list_empty(head) && (head->next == head->prev);
++}
++
+ static inline void __list_splice(struct list_head *list,
+                                struct list_head *head)
+ {