[PATCH 1/4] btrfs: typo: 'btrfS' -> 'btrfs'

[PATCH 1/4] btrfs: typo: 'btrfS' -> 'btrfs'

[slyich]

From: Sergei Trofimovich <st@anti-virus.by>

Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
---
 fs/btrfs/dir-item.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/btrfs/dir-item.c b/fs/btrfs/dir-item.c
index c62f02f..dec9348 100644
--- a/fs/btrfs/dir-item.c
+++ b/fs/btrfs/dir-item.c
@@ -452,7 +452,7 @@ int verify_dir_item(struct btrfs_root *root,
 		namelen = XATTR_NAME_MAX;
 
 	if (btrfs_dir_name_len(leaf, dir_item) > namelen) {
-		printk(KERN_CRIT "btrfS: invalid dir item name len: %u\n",
+		printk(KERN_CRIT "btrfs: invalid dir item name len: %u\n",
 		       (unsigned)btrfs_dir_data_len(leaf, dir_item));
 		return 1;
 	}
-- 
1.7.3.4

[PATCH 3/4] btrfs: don't spin in shrink_delalloc if there is nothing to free

[slyich]

Observed as a large delay when --mixed filesystem is filled up.
Test example:
1. create tiny --mixed FS:
   $ dd if=/dev/zero of=2G.img seek=$((2048 * 1024 * 1024 - 1)) count=1 bs=1
   $ mkfs.btrfs --mixed 2G.img
   $ mount -oloop 2G.img /mnt/ut/
2. Try to fill it up:
   $ dd if=/dev/urandom of=10M.file bs=10240 count=1024
   $ seq 1 256 | while read file_no; do echo $file_no; time cp 10M.file ${file_no}.copy; done

Up to '200.copy' it goes fast, but when disk fills-up each -ENOSPC
message takes 3 seconds to pop-up _every_ ENOSPC (and in usermode linux
it's even more: 30-60 seconds!). (Maybe, time depends on kernel's timer resolution).

No IO, no CPU load, just rescheduling. Some debugging revealed busy spinning
in shrink_delalloc.

Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
---
 fs/btrfs/extent-tree.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 9ee6bd5..9f5fdd3 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3425,6 +3425,10 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
 	if (reserved == 0)
 		return 0;
 
+	/* nothing to shrink - nothing to reclaim */
+	if (root->fs_info->delalloc_bytes == 0)
+		return 0;
+
 	max_reclaim = min(reserved, to_reclaim);
 
 	while (loops < 1024) {
-- 
1.7.3.4

[PATCH 4/4] btrfs: fix typo 'testeing' -> 'testing'

[slyich]

Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
---
 fs/btrfs/inode.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7cd8ab0..72650ce 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1310,7 +1310,7 @@ static int btrfs_set_bit_hook(struct inode *inode,
 
 	/*
 	 * set_bit and clear bit hooks normally require _irqsave/restore
-	 * but in this case, we are only testeing for the DELALLOC
+	 * but in this case, we are only testing for the DELALLOC
 	 * bit, which is only set or cleared with irqs on
 	 */
 	if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
@@ -1344,7 +1344,7 @@ static int btrfs_clear_bit_hook(struct inode *inode,
 {
 	/*
 	 * set_bit and clear bit hooks normally require _irqsave/restore
-	 * but in this case, we are only testeing for the DELALLOC
+	 * but in this case, we are only testing for the DELALLOC
 	 * bit, which is only set or cleared with irqs on
 	 */
 	if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
-- 
1.7.3.4

Re: [PATCH 3/4] btrfs: don't spin in shrink_delalloc if there is nothing to free

[Josef Bacik]

On 05/07/2011 05:29 PM, slyich@gmail.com wrote:
> Observed as a large delay when --mixed filesystem is filled up.
> Test example:
> 1. create tiny --mixed FS:
>     $ dd if=/dev/zero of=2G.img seek=$((2048 * 1024 * 1024 - 1)) count=1 bs=1
>     $ mkfs.btrfs --mixed 2G.img
>     $ mount -oloop 2G.img /mnt/ut/
> 2. Try to fill it up:
>     $ dd if=/dev/urandom of=10M.file bs=10240 count=1024
>     $ seq 1 256 | while read file_no; do echo $file_no; time cp 10M.file ${file_no}.copy; done
>
> Up to '200.copy' it goes fast, but when disk fills-up each -ENOSPC
> message takes 3 seconds to pop-up _every_ ENOSPC (and in usermode linux
> it's even more: 30-60 seconds!). (Maybe, time depends on kernel's timer resolution).
>
> No IO, no CPU load, just rescheduling. Some debugging revealed busy spinning
> in shrink_delalloc.
>
> Signed-off-by: Sergei Trofimovich<slyfox@gentoo.org>
> ---
>   fs/btrfs/extent-tree.c |    4 ++++
>   1 files changed, 4 insertions(+), 0 deletions(-)
>
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 9ee6bd5..9f5fdd3 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -3425,6 +3425,10 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
>   	if (reserved == 0)
>   		return 0;
>
> +	/* nothing to shrink - nothing to reclaim */
> +	if (root->fs_info->delalloc_bytes == 0)
> +		return 0;
> +
>   	max_reclaim = min(reserved, to_reclaim);
>
>   	while (loops<  1024) {

Nice catch, you can add

Reviewed-by: Josef Bacik <josef@redhat.com>

Thanks,

Josef

Re: [PATCH 3/4] btrfs: don't spin in shrink_delalloc if there is nothing to free

[Sergei Trofimovich]

[-- Attachment #1: Type: text/plain, Size: 1828 bytes --]

On Mon, 09 May 2011 12:00:28 -0400
Josef Bacik <josef@redhat.com> wrote:

> On 05/07/2011 05:29 PM, slyich@gmail.com wrote:
> > Observed as a large delay when --mixed filesystem is filled up.
> > Test example:
> > 1. create tiny --mixed FS:
> >     $ dd if=/dev/zero of=2G.img seek=$((2048 * 1024 * 1024 - 1)) count=1 bs=1
> >     $ mkfs.btrfs --mixed 2G.img
> >     $ mount -oloop 2G.img /mnt/ut/
> > 2. Try to fill it up:
> >     $ dd if=/dev/urandom of=10M.file bs=10240 count=1024
> >     $ seq 1 256 | while read file_no; do echo $file_no; time cp 10M.file ${file_no}.copy; done
> >
> > Up to '200.copy' it goes fast, but when disk fills-up each -ENOSPC
> > message takes 3 seconds to pop-up _every_ ENOSPC (and in usermode linux
> > it's even more: 30-60 seconds!). (Maybe, time depends on kernel's timer resolution).
> >
> > No IO, no CPU load, just rescheduling. Some debugging revealed busy spinning
> > in shrink_delalloc.
> >
> > Signed-off-by: Sergei Trofimovich<slyfox@gentoo.org>
> > ---
> >   fs/btrfs/extent-tree.c |    4 ++++
> >   1 files changed, 4 insertions(+), 0 deletions(-)
> >
> > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> > index 9ee6bd5..9f5fdd3 100644
> > --- a/fs/btrfs/extent-tree.c
> > +++ b/fs/btrfs/extent-tree.c
> > @@ -3425,6 +3425,10 @@ static int shrink_delalloc(struct btrfs_trans_handle *trans,
> >   	if (reserved == 0)
> >   		return 0;
> >
> > +	/* nothing to shrink - nothing to reclaim */
> > +	if (root->fs_info->delalloc_bytes == 0)
> > +		return 0;
> > +
> >   	max_reclaim = min(reserved, to_reclaim);
> >
> >   	while (loops<  1024) {
> 
> Nice catch, you can add
> 
> Reviewed-by: Josef Bacik <josef@redhat.com>

Will add it (and fix patch enumeration) and resend.

Thanks for the review!

-- 

  Sergei

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