[PATCH v3 1/3] ubifs: add a superblock flag for free space fix-up

[PATCH v3 1/3] ubifs: add a superblock flag for free space fix-up

[Matthew L. Creech]

The space_fixup flag can be set in the superblock of a new filesystem by
mkfs.ubifs to indicate that any eraseblocks with free space remaining should be
fixed-up the first time it's mounted (after which the flag is un-set).

Signed-off-by: Matthew L. Creech <mlcreech@gmail.com>
---
 fs/ubifs/debug.c       |    2 ++
 fs/ubifs/sb.c          |    1 +
 fs/ubifs/ubifs-media.h |    2 ++
 fs/ubifs/ubifs.h       |    2 ++
 4 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c
index f7515bd..3dce5f3 100644
--- a/fs/ubifs/debug.c
+++ b/fs/ubifs/debug.c
@@ -316,6 +316,8 @@ void dbg_dump_node(const struct ubifs_info *c,
const void *node)
 		printk(KERN_DEBUG "\tflags          %#x\n", sup_flags);
 		printk(KERN_DEBUG "\t  big_lpt      %u\n",
 		       !!(sup_flags & UBIFS_FLG_BIGLPT));
+		printk(KERN_DEBUG "\t  space_fixup  %u\n",
+		       !!(sup_flags & UBIFS_FLG_SPACE_FIXUP));
 		printk(KERN_DEBUG "\tmin_io_size    %u\n",
 		       le32_to_cpu(sup->min_io_size));
 		printk(KERN_DEBUG "\tleb_size       %u\n",
diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
index bf31b47..291f051 100644
--- a/fs/ubifs/sb.c
+++ b/fs/ubifs/sb.c
@@ -616,6 +616,7 @@ int ubifs_read_superblock(struct ubifs_info *c)
 	c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
 	memcpy(&c->uuid, &sup->uuid, 16);
 	c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
+	c->space_fixup = !!(sup_flags & UBIFS_FLG_SPACE_FIXUP);

 	/* Automatically increase file system size to the maximum size */
 	c->old_leb_cnt = c->leb_cnt;
diff --git a/fs/ubifs/ubifs-media.h b/fs/ubifs/ubifs-media.h
index b922f03..e24380c 100644
--- a/fs/ubifs/ubifs-media.h
+++ b/fs/ubifs/ubifs-media.h
@@ -408,9 +408,11 @@ enum {
  * Superblock flags.
  *
  * UBIFS_FLG_BIGLPT: if "big" LPT model is used if set
+ * UBIFS_FLG_SPACE_FIXUP: first-mount "fixup" of free space within LEBs needed
  */
 enum {
 	UBIFS_FLG_BIGLPT = 0x02,
+	UBIFS_FLG_SPACE_FIXUP = 0x04,
 };

 /**
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 26a7ebe..6f0bfa9 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -1014,6 +1014,7 @@ struct ubifs_debug_info;
  * @cmt_wq: wait queue to sleep on if the log is full and a commit is running
  *
  * @big_lpt: flag that LPT is too big to write whole during commit
+ * @space_fixup: flag indicating that free space in LEBs needs to be cleaned up
  * @no_chk_data_crc: do not check CRCs when reading data nodes (except during
  *                   recovery)
  * @bulk_read: enable bulk-reads
@@ -1254,6 +1255,7 @@ struct ubifs_info {
 	wait_queue_head_t cmt_wq;

 	unsigned int big_lpt:1;
+	unsigned int space_fixup:1;
 	unsigned int no_chk_data_crc:1;
 	unsigned int bulk_read:1;
 	unsigned int default_compr:2;
-- 
1.6.3.3


-- 
Matthew L. Creech

Re: [PATCH v3 1/3] ubifs: add a superblock flag for free space fix-up

[Artem Bityutskiy]

On Thu, 2011-05-05 at 16:33 -0400, Matthew L. Creech wrote:
> The space_fixup flag can be set in the superblock of a new filesystem by
> mkfs.ubifs to indicate that any eraseblocks with free space remaining should be
> fixed-up the first time it's mounted (after which the flag is un-set).
> 
> Signed-off-by: Matthew L. Creech <mlcreech@gmail.com>

Hi, I've made the commit message a bit more verbose, and also added fre
comments into the code, for those who will try to figure out what the
flag means in the future. I've also fixed the patch because it is
line-wrapped. And I've applied this one to the ubifs-2.6.git tree to the
master branch.

> index f7515bd..3dce5f3 100644
> --- a/fs/ubifs/debug.c
> +++ b/fs/ubifs/debug.c
> @@ -316,6 +316,8 @@ void dbg_dump_node(const struct ubifs_info *c,
> const void *node)

This should be one line. Using git send-email could help to avoid this.

-- 
Best Regards,
Artem Bityutskiy (Артём Битюцкий)