* [PATCH 2/2] ext4: annotate all meta data requests
2012-05-11 15:02 [PATCH 1/2] block: add BH_Meta flag Saugata Das
@ 2012-05-11 15:02 ` Saugata Das
2012-05-14 1:42 ` [PATCH 1/2] block: add BH_Meta flag Namhyung Kim
` (2 subsequent siblings)
3 siblings, 0 replies; 7+ messages in thread
From: Saugata Das @ 2012-05-11 15:02 UTC (permalink / raw)
To: linux-ext4, linux-fsdevel
Cc: tytso, adilger, hch, arnd.bergmann, venkat, Saugata Das
From: Saugata Das <saugata.das@linaro.org>
Today, storage devices like eMMC has special features like data tagging
(introduced in MMC-4.5 version) in order to improve performance of some
specific writes. On MMC stack, data tagging is used for all writes which has
REQ_META flag set. On EXT4, however, currently REQ_META is set only for read.
This patch adds the capability mark a meta-data buffer with set_buffer_meta
during meta data write. During submit_bh, this information is used to set
REQ_META flag.
Signed-off-by: Saugata Das <saugata.das@linaro.org>
---
fs/ext4/ext4_jbd2.c | 4 ++++
fs/ext4/inode.c | 4 +++-
2 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c
index aca1790..097c062 100644
--- a/fs/ext4/ext4_jbd2.c
+++ b/fs/ext4/ext4_jbd2.c
@@ -107,6 +107,8 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
{
int err = 0;
+ set_buffer_meta(bh);
+
if (ext4_handle_valid(handle)) {
err = jbd2_journal_dirty_metadata(handle, bh);
if (err) {
@@ -143,6 +145,8 @@ int __ext4_handle_dirty_super(const char *where, unsigned int line,
struct buffer_head *bh = EXT4_SB(sb)->s_sbh;
int err = 0;
+ set_buffer_meta(bh);
+
if (ext4_handle_valid(handle)) {
err = jbd2_journal_dirty_metadata(handle, bh);
if (err)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c77b0bd..754fe77 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4035,8 +4035,10 @@ int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
err = __ext4_get_inode_loc(inode, &iloc, 0);
if (err)
return err;
- if (wbc->sync_mode == WB_SYNC_ALL)
+ if (wbc->sync_mode == WB_SYNC_ALL) {
+ set_buffer_meta(iloc.bh);
sync_dirty_buffer(iloc.bh);
+ }
if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) {
EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr,
"IO error syncing inode");
--
1.7.4.3
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH 1/2] block: add BH_Meta flag
2012-05-11 15:02 [PATCH 1/2] block: add BH_Meta flag Saugata Das
2012-05-11 15:02 ` [PATCH 2/2] ext4: annotate all meta data requests Saugata Das
@ 2012-05-14 1:42 ` Namhyung Kim
2012-05-14 4:54 ` Saugata Das
2012-05-16 11:57 ` Saugata Das
2012-05-16 12:32 ` Boaz Harrosh
3 siblings, 1 reply; 7+ messages in thread
From: Namhyung Kim @ 2012-05-14 1:42 UTC (permalink / raw)
To: Saugata Das
Cc: linux-ext4, linux-fsdevel, tytso, adilger, hch, arnd.bergmann,
venkat, Saugata Das
Hi,
On Fri, 11 May 2012 20:32:56 +0530, Saugata Das wrote:
> From: Saugata Das <saugata.das@linaro.org>
>
> Today, storage devices like eMMC has special features like data tagging
> (introduced in MMC-4.5 version) in order to improve performance of some
> specific writes. On MMC stack, data tagging is used for all writes which
> has REQ_META flag set. This patch adds the capability to add REQ_META flag
> during meta data write.
>
AFAIK, the REQ_META is only for marking a bio/req to be recognized when
using blktrace or something. You can use REQ_PRIO for the purpose but it
applies only if your ioscheduler is CFQ.
But I'm not aware how the MMC stack works, so I might be missing something.
Thanks,
Namhyung
> Signed-off-by: Saugata Das <saugata.das@linaro.org>
> ---
> fs/buffer.c | 10 ++++++++--
> include/linux/buffer_head.h | 2 ++
> 2 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/fs/buffer.c b/fs/buffer.c
> index 36d6665..688b38b 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -1685,7 +1685,10 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
> do {
> struct buffer_head *next = bh->b_this_page;
> if (buffer_async_write(bh)) {
> - submit_bh(write_op, bh);
> + if (buffer_meta(bh))
> + submit_bh(write_op | REQ_META, bh);
> + else
> + submit_bh(write_op, bh);
> nr_underway++;
> }
> bh = next;
> @@ -1739,7 +1742,10 @@ recover:
> struct buffer_head *next = bh->b_this_page;
> if (buffer_async_write(bh)) {
> clear_buffer_dirty(bh);
> - submit_bh(write_op, bh);
> + if (buffer_meta(bh))
> + submit_bh(write_op | REQ_META, bh);
> + else
> + submit_bh(write_op, bh);
> nr_underway++;
> }
> bh = next;
> diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
> index ef26043..0776564 100644
> --- a/include/linux/buffer_head.h
> +++ b/include/linux/buffer_head.h
> @@ -34,6 +34,7 @@ enum bh_state_bits {
> BH_Write_EIO, /* I/O error on write */
> BH_Unwritten, /* Buffer is allocated on disk but not written */
> BH_Quiet, /* Buffer Error Prinks to be quiet */
> + BH_Meta, /* Is meta */
>
> BH_PrivateStart,/* not a state bit, but the first bit available
> * for private allocation by other entities
> @@ -126,6 +127,7 @@ BUFFER_FNS(Delay, delay)
> BUFFER_FNS(Boundary, boundary)
> BUFFER_FNS(Write_EIO, write_io_error)
> BUFFER_FNS(Unwritten, unwritten)
> +BUFFER_FNS(Meta, meta)
>
> #define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
> #define touch_buffer(bh) mark_page_accessed(bh->b_page)
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH 1/2] block: add BH_Meta flag
2012-05-14 1:42 ` [PATCH 1/2] block: add BH_Meta flag Namhyung Kim
@ 2012-05-14 4:54 ` Saugata Das
0 siblings, 0 replies; 7+ messages in thread
From: Saugata Das @ 2012-05-14 4:54 UTC (permalink / raw)
To: Namhyung Kim
Cc: Saugata Das, linux-ext4, linux-fsdevel, tytso, adilger, hch,
arnd.bergmann, venkat
On 14 May 2012 07:12, Namhyung Kim <namhyung.kim@lge.com> wrote:
> Hi,
>
> On Fri, 11 May 2012 20:32:56 +0530, Saugata Das wrote:
>> From: Saugata Das <saugata.das@linaro.org>
>>
>> Today, storage devices like eMMC has special features like data tagging
>> (introduced in MMC-4.5 version) in order to improve performance of some
>> specific writes. On MMC stack, data tagging is used for all writes which
>> has REQ_META flag set. This patch adds the capability to add REQ_META flag
>> during meta data write.
>>
>
> AFAIK, the REQ_META is only for marking a bio/req to be recognized when
> using blktrace or something. You can use REQ_PRIO for the purpose but it
> applies only if your ioscheduler is CFQ.
>
> But I'm not aware how the MMC stack works, so I might be missing something.
>
Today on ext4, REQ_META or REQ_PRIO are only used during read
operation. For meta-data writes, no special flag (REQ_META or
REQ_PRIO) is set.
On eMMC, we depend on REQ_META flag to implement the "reliable write"
and "data tag" feature, which are linked with additional reliability
and performance for file system meta-data writes.
> Thanks,
> Namhyung
>
>
>> Signed-off-by: Saugata Das <saugata.das@linaro.org>
>> ---
>> fs/buffer.c | 10 ++++++++--
>> include/linux/buffer_head.h | 2 ++
>> 2 files changed, 10 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/buffer.c b/fs/buffer.c
>> index 36d6665..688b38b 100644
>> --- a/fs/buffer.c
>> +++ b/fs/buffer.c
>> @@ -1685,7 +1685,10 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
>> do {
>> struct buffer_head *next = bh->b_this_page;
>> if (buffer_async_write(bh)) {
>> - submit_bh(write_op, bh);
>> + if (buffer_meta(bh))
>> + submit_bh(write_op | REQ_META, bh);
>> + else
>> + submit_bh(write_op, bh);
>> nr_underway++;
>> }
>> bh = next;
>> @@ -1739,7 +1742,10 @@ recover:
>> struct buffer_head *next = bh->b_this_page;
>> if (buffer_async_write(bh)) {
>> clear_buffer_dirty(bh);
>> - submit_bh(write_op, bh);
>> + if (buffer_meta(bh))
>> + submit_bh(write_op | REQ_META, bh);
>> + else
>> + submit_bh(write_op, bh);
>> nr_underway++;
>> }
>> bh = next;
>> diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
>> index ef26043..0776564 100644
>> --- a/include/linux/buffer_head.h
>> +++ b/include/linux/buffer_head.h
>> @@ -34,6 +34,7 @@ enum bh_state_bits {
>> BH_Write_EIO, /* I/O error on write */
>> BH_Unwritten, /* Buffer is allocated on disk but not written */
>> BH_Quiet, /* Buffer Error Prinks to be quiet */
>> + BH_Meta, /* Is meta */
>>
>> BH_PrivateStart,/* not a state bit, but the first bit available
>> * for private allocation by other entities
>> @@ -126,6 +127,7 @@ BUFFER_FNS(Delay, delay)
>> BUFFER_FNS(Boundary, boundary)
>> BUFFER_FNS(Write_EIO, write_io_error)
>> BUFFER_FNS(Unwritten, unwritten)
>> +BUFFER_FNS(Meta, meta)
>>
>> #define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
>> #define touch_buffer(bh) mark_page_accessed(bh->b_page)
--
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More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH 1/2] block: add BH_Meta flag
2012-05-11 15:02 [PATCH 1/2] block: add BH_Meta flag Saugata Das
2012-05-11 15:02 ` [PATCH 2/2] ext4: annotate all meta data requests Saugata Das
2012-05-14 1:42 ` [PATCH 1/2] block: add BH_Meta flag Namhyung Kim
@ 2012-05-16 11:57 ` Saugata Das
2012-05-16 12:32 ` Boaz Harrosh
3 siblings, 0 replies; 7+ messages in thread
From: Saugata Das @ 2012-05-16 11:57 UTC (permalink / raw)
To: tytso, hch
Cc: adilger, arnd.bergmann, venkat, Deepak Saxena,
Saugata Das PURKAYASTHA, linux-ext4, linux-fsdevel
Hi Ted, Christoph
Will you please comment on the following patch set,
[PATCH 1/2] block: add BH_Meta flag
[PATCH 2/2] ext4: annotate all meta data requests
If there is no remark, then will you please merge them to the next version.
Thanks,
Saugata
On 11 May 2012 20:32, Saugata Das <saugata.das@stericsson.com> wrote:
> From: Saugata Das <saugata.das@linaro.org>
>
> Today, storage devices like eMMC has special features like data tagging
> (introduced in MMC-4.5 version) in order to improve performance of some
> specific writes. On MMC stack, data tagging is used for all writes which
> has REQ_META flag set. This patch adds the capability to add REQ_META flag
> during meta data write.
>
> Signed-off-by: Saugata Das <saugata.das@linaro.org>
> ---
> fs/buffer.c | 10 ++++++++--
> include/linux/buffer_head.h | 2 ++
> 2 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/fs/buffer.c b/fs/buffer.c
> index 36d6665..688b38b 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -1685,7 +1685,10 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
> do {
> struct buffer_head *next = bh->b_this_page;
> if (buffer_async_write(bh)) {
> - submit_bh(write_op, bh);
> + if (buffer_meta(bh))
> + submit_bh(write_op | REQ_META, bh);
> + else
> + submit_bh(write_op, bh);
> nr_underway++;
> }
> bh = next;
> @@ -1739,7 +1742,10 @@ recover:
> struct buffer_head *next = bh->b_this_page;
> if (buffer_async_write(bh)) {
> clear_buffer_dirty(bh);
> - submit_bh(write_op, bh);
> + if (buffer_meta(bh))
> + submit_bh(write_op | REQ_META, bh);
> + else
> + submit_bh(write_op, bh);
> nr_underway++;
> }
> bh = next;
> diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
> index ef26043..0776564 100644
> --- a/include/linux/buffer_head.h
> +++ b/include/linux/buffer_head.h
> @@ -34,6 +34,7 @@ enum bh_state_bits {
> BH_Write_EIO, /* I/O error on write */
> BH_Unwritten, /* Buffer is allocated on disk but not written */
> BH_Quiet, /* Buffer Error Prinks to be quiet */
> + BH_Meta, /* Is meta */
>
> BH_PrivateStart,/* not a state bit, but the first bit available
> * for private allocation by other entities
> @@ -126,6 +127,7 @@ BUFFER_FNS(Delay, delay)
> BUFFER_FNS(Boundary, boundary)
> BUFFER_FNS(Write_EIO, write_io_error)
> BUFFER_FNS(Unwritten, unwritten)
> +BUFFER_FNS(Meta, meta)
>
> #define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
> #define touch_buffer(bh) mark_page_accessed(bh->b_page)
> --
> 1.7.4.3
>
--
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the body of a message to majordomo@vger.kernel.org
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^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH 1/2] block: add BH_Meta flag
2012-05-11 15:02 [PATCH 1/2] block: add BH_Meta flag Saugata Das
` (2 preceding siblings ...)
2012-05-16 11:57 ` Saugata Das
@ 2012-05-16 12:32 ` Boaz Harrosh
2012-05-16 14:06 ` Saugata Das
3 siblings, 1 reply; 7+ messages in thread
From: Boaz Harrosh @ 2012-05-16 12:32 UTC (permalink / raw)
To: Saugata Das
Cc: linux-ext4, linux-fsdevel, tytso, adilger, hch, arnd.bergmann,
venkat, Saugata Das
On 05/11/2012 06:02 PM, Saugata Das wrote:
> From: Saugata Das <saugata.das@linaro.org>
>
> Today, storage devices like eMMC has special features like data tagging
> (introduced in MMC-4.5 version) in order to improve performance of some
> specific writes. On MMC stack, data tagging is used for all writes which
> has REQ_META flag set. This patch adds the capability to add REQ_META flag
> during meta data write.
>
> Signed-off-by: Saugata Das <saugata.das@linaro.org>
> ---
> fs/buffer.c | 10 ++++++++--
> include/linux/buffer_head.h | 2 ++
> 2 files changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/fs/buffer.c b/fs/buffer.c
> index 36d6665..688b38b 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -1685,7 +1685,10 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
> do {
> struct buffer_head *next = bh->b_this_page;
> if (buffer_async_write(bh)) {
> - submit_bh(write_op, bh);
> + if (buffer_meta(bh))
> + submit_bh(write_op | REQ_META, bh);
> + else
> + submit_bh(write_op, bh);
Its not nice to duplicate a call site for the parameter difference
it's better to change the parameter and call the function in one
place. (an assembler call site can get big)
You can do:
+ submit_bh(write_op | (buffer_meta(bh) << __REQ_META), bh);
And also avoid a conditional inside a loop.
> nr_underway++;
> }
> bh = next;
> @@ -1739,7 +1742,10 @@ recover:
> struct buffer_head *next = bh->b_this_page;
> if (buffer_async_write(bh)) {
> clear_buffer_dirty(bh);
> - submit_bh(write_op, bh);
> + if (buffer_meta(bh))
> + submit_bh(write_op | REQ_META, bh);
> + else
> + submit_bh(write_op, bh);
Here too
Boaz
> nr_underway++;
> }
> bh = next;
> diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
> index ef26043..0776564 100644
> --- a/include/linux/buffer_head.h
> +++ b/include/linux/buffer_head.h
> @@ -34,6 +34,7 @@ enum bh_state_bits {
> BH_Write_EIO, /* I/O error on write */
> BH_Unwritten, /* Buffer is allocated on disk but not written */
> BH_Quiet, /* Buffer Error Prinks to be quiet */
> + BH_Meta, /* Is meta */
>
> BH_PrivateStart,/* not a state bit, but the first bit available
> * for private allocation by other entities
> @@ -126,6 +127,7 @@ BUFFER_FNS(Delay, delay)
> BUFFER_FNS(Boundary, boundary)
> BUFFER_FNS(Write_EIO, write_io_error)
> BUFFER_FNS(Unwritten, unwritten)
> +BUFFER_FNS(Meta, meta)
>
> #define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
> #define touch_buffer(bh) mark_page_accessed(bh->b_page)
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH 1/2] block: add BH_Meta flag
2012-05-16 12:32 ` Boaz Harrosh
@ 2012-05-16 14:06 ` Saugata Das
0 siblings, 0 replies; 7+ messages in thread
From: Saugata Das @ 2012-05-16 14:06 UTC (permalink / raw)
To: Boaz Harrosh
Cc: Saugata Das, linux-ext4, linux-fsdevel, tytso, adilger, hch,
arnd.bergmann, venkat
On 16 May 2012 18:02, Boaz Harrosh <bharrosh@panasas.com> wrote:
> On 05/11/2012 06:02 PM, Saugata Das wrote:
>
>> From: Saugata Das <saugata.das@linaro.org>
>>
>> Today, storage devices like eMMC has special features like data tagging
>> (introduced in MMC-4.5 version) in order to improve performance of some
>> specific writes. On MMC stack, data tagging is used for all writes which
>> has REQ_META flag set. This patch adds the capability to add REQ_META flag
>> during meta data write.
>>
>> Signed-off-by: Saugata Das <saugata.das@linaro.org>
>> ---
>> fs/buffer.c | 10 ++++++++--
>> include/linux/buffer_head.h | 2 ++
>> 2 files changed, 10 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/buffer.c b/fs/buffer.c
>> index 36d6665..688b38b 100644
>> --- a/fs/buffer.c
>> +++ b/fs/buffer.c
>> @@ -1685,7 +1685,10 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
>> do {
>> struct buffer_head *next = bh->b_this_page;
>> if (buffer_async_write(bh)) {
>> - submit_bh(write_op, bh);
>> + if (buffer_meta(bh))
>> + submit_bh(write_op | REQ_META, bh);
>> + else
>> + submit_bh(write_op, bh);
>
>
> Its not nice to duplicate a call site for the parameter difference
> it's better to change the parameter and call the function in one
> place. (an assembler call site can get big)
>
> You can do:
> + submit_bh(write_op | (buffer_meta(bh) << __REQ_META), bh);
>
> And also avoid a conditional inside a loop.
>
Thanks for your comments. I will take care of this in the next version.
>
>> nr_underway++;
>> }
>> bh = next;
>> @@ -1739,7 +1742,10 @@ recover:
>> struct buffer_head *next = bh->b_this_page;
>> if (buffer_async_write(bh)) {
>> clear_buffer_dirty(bh);
>> - submit_bh(write_op, bh);
>> + if (buffer_meta(bh))
>> + submit_bh(write_op | REQ_META, bh);
>> + else
>> + submit_bh(write_op, bh);
>
>
> Here too
>
> Boaz
>
>> nr_underway++;
>> }
>> bh = next;
>> diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
>> index ef26043..0776564 100644
>> --- a/include/linux/buffer_head.h
>> +++ b/include/linux/buffer_head.h
>> @@ -34,6 +34,7 @@ enum bh_state_bits {
>> BH_Write_EIO, /* I/O error on write */
>> BH_Unwritten, /* Buffer is allocated on disk but not written */
>> BH_Quiet, /* Buffer Error Prinks to be quiet */
>> + BH_Meta, /* Is meta */
>>
>> BH_PrivateStart,/* not a state bit, but the first bit available
>> * for private allocation by other entities
>> @@ -126,6 +127,7 @@ BUFFER_FNS(Delay, delay)
>> BUFFER_FNS(Boundary, boundary)
>> BUFFER_FNS(Write_EIO, write_io_error)
>> BUFFER_FNS(Unwritten, unwritten)
>> +BUFFER_FNS(Meta, meta)
>>
>> #define bh_offset(bh) ((unsigned long)(bh)->b_data & ~PAGE_MASK)
>> #define touch_buffer(bh) mark_page_accessed(bh->b_page)
>
>
--
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^ permalink raw reply [flat|nested] 7+ messages in thread