* [PATCH 1/4] fs/btrfs: Convert kmap to kmap_local_page() using coccinelle
2021-02-17 2:48 [PATCH 0/4] btrfs: Convert more kmaps to kmap_local_page() ira.weiny
@ 2021-02-17 2:48 ` ira.weiny
2021-03-12 18:58 ` David Sterba
2021-02-17 2:48 ` [PATCH 2/4] fs/btrfs: Convert raid5/6 kmaps to kmap_local_page() ira.weiny
` (4 subsequent siblings)
5 siblings, 1 reply; 14+ messages in thread
From: ira.weiny @ 2021-02-17 2:48 UTC (permalink / raw)
To: David Sterba
Cc: Ira Weiny, Chris Mason, Josef Bacik, linux-kernel, linux-fsdevel
From: Ira Weiny <ira.weiny@intel.com>
Use a simple coccinelle script to help convert the most common
kmap()/kunmap() patterns to kmap_local_page()/kunmap_local().
Note that some kmaps which were caught by this script needed to be
handled by hand because of the strict unmapping order of kunmap_local()
so they are not included in this patch. But this script got us started.
The development of this patch was aided by the follow script:
// <smpl>
// SPDX-License-Identifier: GPL-2.0-only
// Find kmap and replace with kmap_local_page then mark kunmap
//
// Confidence: Low
// Copyright: (C) 2021 Intel Corporation
// URL: http://coccinelle.lip6.fr/
@ catch_all @
expression e, e2;
@@
(
-kmap(e)
+kmap_local_page(e)
)
...
(
-kunmap(...)
+kunmap_local()
)
// </smpl>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
fs/btrfs/compression.c | 4 ++--
fs/btrfs/inode.c | 4 ++--
fs/btrfs/lzo.c | 9 ++++-----
fs/btrfs/raid56.c | 4 ++--
4 files changed, 10 insertions(+), 11 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index a219dcdb749e..21833a2fe8c6 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -1578,7 +1578,7 @@ static void heuristic_collect_sample(struct inode *inode, u64 start, u64 end,
curr_sample_pos = 0;
while (index < index_end) {
page = find_get_page(inode->i_mapping, index);
- in_data = kmap(page);
+ in_data = kmap_local_page(page);
/* Handle case where the start is not aligned to PAGE_SIZE */
i = start % PAGE_SIZE;
while (i < PAGE_SIZE - SAMPLING_READ_SIZE) {
@@ -1591,7 +1591,7 @@ static void heuristic_collect_sample(struct inode *inode, u64 start, u64 end,
start += SAMPLING_INTERVAL;
curr_sample_pos += SAMPLING_READ_SIZE;
}
- kunmap(page);
+ kunmap_local(in_data);
put_page(page);
index++;
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 641f21a11722..66c6f1185de2 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6845,7 +6845,7 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
if (ret)
goto out;
} else {
- map = kmap(page);
+ map = kmap_local_page(page);
read_extent_buffer(leaf, map + pg_offset, ptr,
copy_size);
if (pg_offset + copy_size < PAGE_SIZE) {
@@ -6853,7 +6853,7 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
PAGE_SIZE - pg_offset -
copy_size);
}
- kunmap(page);
+ kunmap_local(map);
}
flush_dcache_page(page);
}
diff --git a/fs/btrfs/lzo.c b/fs/btrfs/lzo.c
index 9084a950dc09..cd042c7567a4 100644
--- a/fs/btrfs/lzo.c
+++ b/fs/btrfs/lzo.c
@@ -118,7 +118,7 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
struct workspace *workspace = list_entry(ws, struct workspace, list);
int ret = 0;
char *data_in;
- char *cpage_out;
+ char *cpage_out, *sizes_ptr;
int nr_pages = 0;
struct page *in_page = NULL;
struct page *out_page = NULL;
@@ -258,10 +258,9 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
}
/* store the size of all chunks of compressed data */
- cpage_out = kmap(pages[0]);
- write_compress_length(cpage_out, tot_out);
-
- kunmap(pages[0]);
+ sizes_ptr = kmap_local_page(pages[0]);
+ write_compress_length(sizes_ptr, tot_out);
+ kunmap_local(sizes_ptr);
ret = 0;
*total_out = tot_out;
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 7c3f6dc918c1..9759fb31b73e 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -2391,13 +2391,13 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
/* Check scrubbing parity and repair it */
p = rbio_stripe_page(rbio, rbio->scrubp, pagenr);
- parity = kmap(p);
+ parity = kmap_local_page(p);
if (memcmp(parity, pointers[rbio->scrubp], PAGE_SIZE))
copy_page(parity, pointers[rbio->scrubp]);
else
/* Parity is right, needn't writeback */
bitmap_clear(rbio->dbitmap, pagenr, 1);
- kunmap(p);
+ kunmap_local(parity);
for (stripe = 0; stripe < nr_data; stripe++)
kunmap(page_in_rbio(rbio, stripe, pagenr, 0));
--
2.28.0.rc0.12.gb6a658bd00c9
^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH 1/4] fs/btrfs: Convert kmap to kmap_local_page() using coccinelle
2021-02-17 2:48 ` [PATCH 1/4] fs/btrfs: Convert kmap to kmap_local_page() using coccinelle ira.weiny
@ 2021-03-12 18:58 ` David Sterba
2021-03-12 20:03 ` Ira Weiny
0 siblings, 1 reply; 14+ messages in thread
From: David Sterba @ 2021-03-12 18:58 UTC (permalink / raw)
To: ira.weiny; +Cc: Chris Mason, Josef Bacik, linux-kernel, linux-fsdevel
On Tue, Feb 16, 2021 at 06:48:23PM -0800, ira.weiny@intel.com wrote:
> --- a/fs/btrfs/lzo.c
> +++ b/fs/btrfs/lzo.c
> @@ -118,7 +118,7 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
> struct workspace *workspace = list_entry(ws, struct workspace, list);
> int ret = 0;
> char *data_in;
> - char *cpage_out;
> + char *cpage_out, *sizes_ptr;
> int nr_pages = 0;
> struct page *in_page = NULL;
> struct page *out_page = NULL;
> @@ -258,10 +258,9 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
> }
>
> /* store the size of all chunks of compressed data */
> - cpage_out = kmap(pages[0]);
> - write_compress_length(cpage_out, tot_out);
> -
> - kunmap(pages[0]);
> + sizes_ptr = kmap_local_page(pages[0]);
> + write_compress_length(sizes_ptr, tot_out);
> + kunmap_local(sizes_ptr);
Why is not cpage_out reused for this mapping? I don't see any reason for
another temporary variable, cpage_out is not used at this point.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 1/4] fs/btrfs: Convert kmap to kmap_local_page() using coccinelle
2021-03-12 18:58 ` David Sterba
@ 2021-03-12 20:03 ` Ira Weiny
2021-03-16 11:04 ` David Sterba
0 siblings, 1 reply; 14+ messages in thread
From: Ira Weiny @ 2021-03-12 20:03 UTC (permalink / raw)
To: dsterba, Chris Mason, Josef Bacik, linux-kernel, linux-fsdevel
On Fri, Mar 12, 2021 at 07:58:39PM +0100, David Sterba wrote:
> On Tue, Feb 16, 2021 at 06:48:23PM -0800, ira.weiny@intel.com wrote:
> > --- a/fs/btrfs/lzo.c
> > +++ b/fs/btrfs/lzo.c
> > @@ -118,7 +118,7 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
> > struct workspace *workspace = list_entry(ws, struct workspace, list);
> > int ret = 0;
> > char *data_in;
> > - char *cpage_out;
> > + char *cpage_out, *sizes_ptr;
> > int nr_pages = 0;
> > struct page *in_page = NULL;
> > struct page *out_page = NULL;
> > @@ -258,10 +258,9 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
> > }
> >
> > /* store the size of all chunks of compressed data */
> > - cpage_out = kmap(pages[0]);
> > - write_compress_length(cpage_out, tot_out);
> > -
> > - kunmap(pages[0]);
> > + sizes_ptr = kmap_local_page(pages[0]);
> > + write_compress_length(sizes_ptr, tot_out);
> > + kunmap_local(sizes_ptr);
>
> Why is not cpage_out reused for this mapping? I don't see any reason for
> another temporary variable, cpage_out is not used at this point.
For this patch that is true. However, I'm trying to convert the other kmaps as
well. To do that I'll need cpage_out preserved for the final kunmap_local().
Unfortunately, the required nesting ordering of kmap_local_page() makes
converting the other calls hacky at best. I'm not sure what to do about them.
The best I've come up with is doing a hacky extra unmap/remap to preserve the
nesting.
Anyway, I'd prefer to leave this additional temp variable but I can certainly
change if it you want. The other conversions may never work/land. :-/
Ira
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 1/4] fs/btrfs: Convert kmap to kmap_local_page() using coccinelle
2021-03-12 20:03 ` Ira Weiny
@ 2021-03-16 11:04 ` David Sterba
0 siblings, 0 replies; 14+ messages in thread
From: David Sterba @ 2021-03-16 11:04 UTC (permalink / raw)
To: Ira Weiny; +Cc: dsterba, Chris Mason, Josef Bacik, linux-kernel, linux-fsdevel
On Fri, Mar 12, 2021 at 12:03:14PM -0800, Ira Weiny wrote:
> On Fri, Mar 12, 2021 at 07:58:39PM +0100, David Sterba wrote:
> > On Tue, Feb 16, 2021 at 06:48:23PM -0800, ira.weiny@intel.com wrote:
> > > --- a/fs/btrfs/lzo.c
> > > +++ b/fs/btrfs/lzo.c
> > > @@ -118,7 +118,7 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
> > > struct workspace *workspace = list_entry(ws, struct workspace, list);
> > > int ret = 0;
> > > char *data_in;
> > > - char *cpage_out;
> > > + char *cpage_out, *sizes_ptr;
> > > int nr_pages = 0;
> > > struct page *in_page = NULL;
> > > struct page *out_page = NULL;
> > > @@ -258,10 +258,9 @@ int lzo_compress_pages(struct list_head *ws, struct address_space *mapping,
> > > }
> > >
> > > /* store the size of all chunks of compressed data */
> > > - cpage_out = kmap(pages[0]);
> > > - write_compress_length(cpage_out, tot_out);
> > > -
> > > - kunmap(pages[0]);
> > > + sizes_ptr = kmap_local_page(pages[0]);
> > > + write_compress_length(sizes_ptr, tot_out);
> > > + kunmap_local(sizes_ptr);
> >
> > Why is not cpage_out reused for this mapping? I don't see any reason for
> > another temporary variable, cpage_out is not used at this point.
>
> For this patch that is true. However, I'm trying to convert the other kmaps as
> well. To do that I'll need cpage_out preserved for the final kunmap_local().
>
> Unfortunately, the required nesting ordering of kmap_local_page() makes
> converting the other calls hacky at best. I'm not sure what to do about them.
> The best I've come up with is doing a hacky extra unmap/remap to preserve the
> nesting.
>
> Anyway, I'd prefer to leave this additional temp variable but I can certainly
> change if it you want. The other conversions may never work/land. :-/
Ok, no problem keeping the variable then. I've added a note to changelog
why it's there. The whole conversion sounds tricky so adding trivial
helper code is no big deal.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH 2/4] fs/btrfs: Convert raid5/6 kmaps to kmap_local_page()
2021-02-17 2:48 [PATCH 0/4] btrfs: Convert more kmaps to kmap_local_page() ira.weiny
2021-02-17 2:48 ` [PATCH 1/4] fs/btrfs: Convert kmap to kmap_local_page() using coccinelle ira.weiny
@ 2021-02-17 2:48 ` ira.weiny
2021-03-12 19:26 ` David Sterba
2021-02-17 2:48 ` [PATCH 3/4] fs/btrfs: Use kmap_local_page() in __btrfsic_submit_bio() ira.weiny
` (3 subsequent siblings)
5 siblings, 1 reply; 14+ messages in thread
From: ira.weiny @ 2021-02-17 2:48 UTC (permalink / raw)
To: David Sterba
Cc: Ira Weiny, Chris Mason, Josef Bacik, linux-kernel, linux-fsdevel
From: Ira Weiny <ira.weiny@intel.com>
These kmaps are thread local and don't need to be atomic. So they can use
the more efficient kmap_local_page(). However, the mapping of pages in
the stripes and the additional parity and qstripe pages are a bit
trickier because the unmapping must occur in the opposite order from the
mapping. Furthermore, the pointer array in __raid_recover_end_io() may
get reordered.
Convert these calls to kmap_local_page() taking care to reverse the
unmappings of any page arrays as well as being careful with the mappings
of any special pages such as the parity and qstripe pages.
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
This patch depends on the fix to raid5/6 kmapping sent previously
https://lore.kernel.org/lkml/20210205163943.GD5033@iweiny-DESK2.sc.intel.com/#t
---
fs/btrfs/raid56.c | 57 +++++++++++++++++++++++------------------------
1 file changed, 28 insertions(+), 29 deletions(-)
diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
index 9759fb31b73e..04abae305582 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -1233,13 +1233,13 @@ static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
/* first collect one page from each data stripe */
for (stripe = 0; stripe < nr_data; stripe++) {
p = page_in_rbio(rbio, stripe, pagenr, 0);
- pointers[stripe] = kmap(p);
+ pointers[stripe] = kmap_local_page(p);
}
/* then add the parity stripe */
p = rbio_pstripe_page(rbio, pagenr);
SetPageUptodate(p);
- pointers[stripe++] = kmap(p);
+ pointers[stripe++] = kmap_local_page(p);
if (has_qstripe) {
@@ -1249,7 +1249,7 @@ static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
*/
p = rbio_qstripe_page(rbio, pagenr);
SetPageUptodate(p);
- pointers[stripe++] = kmap(p);
+ pointers[stripe++] = kmap_local_page(p);
raid6_call.gen_syndrome(rbio->real_stripes, PAGE_SIZE,
pointers);
@@ -1258,10 +1258,8 @@ static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
copy_page(pointers[nr_data], pointers[0]);
run_xor(pointers + 1, nr_data - 1, PAGE_SIZE);
}
-
-
- for (stripe = 0; stripe < rbio->real_stripes; stripe++)
- kunmap(page_in_rbio(rbio, stripe, pagenr, 0));
+ for (stripe = stripe - 1; stripe >= 0; stripe--)
+ kunmap_local(pointers[stripe]);
}
/*
@@ -1780,6 +1778,7 @@ static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
{
int pagenr, stripe;
void **pointers;
+ void **unmap_array;
int faila = -1, failb = -1;
struct page *page;
blk_status_t err;
@@ -1791,6 +1790,12 @@ static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
goto cleanup_io;
}
+ unmap_array = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
+ if (!unmap_array) {
+ err = BLK_STS_RESOURCE;
+ goto cleanup_pointers;
+ }
+
faila = rbio->faila;
failb = rbio->failb;
@@ -1814,6 +1819,9 @@ static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
/* setup our array of pointers with pages
* from each stripe
+ *
+ * NOTE Store a duplicate array of pointers to preserve the
+ * pointer order.
*/
for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
/*
@@ -1827,7 +1835,8 @@ static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
} else {
page = rbio_stripe_page(rbio, stripe, pagenr);
}
- pointers[stripe] = kmap(page);
+ pointers[stripe] = kmap_local_page(page);
+ unmap_array[stripe] = pointers[stripe];
}
/* all raid6 handling here */
@@ -1920,24 +1929,14 @@ static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
}
}
}
- for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
- /*
- * if we're rebuilding a read, we have to use
- * pages from the bio list
- */
- if ((rbio->operation == BTRFS_RBIO_READ_REBUILD ||
- rbio->operation == BTRFS_RBIO_REBUILD_MISSING) &&
- (stripe == faila || stripe == failb)) {
- page = page_in_rbio(rbio, stripe, pagenr, 0);
- } else {
- page = rbio_stripe_page(rbio, stripe, pagenr);
- }
- kunmap(page);
- }
+ for (stripe = rbio->real_stripes - 1; stripe >= 0; stripe--)
+ kunmap_local(unmap_array[stripe]);
}
err = BLK_STS_OK;
cleanup:
+ kfree(unmap_array);
+cleanup_pointers:
kfree(pointers);
cleanup_io:
@@ -2362,13 +2361,13 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
goto cleanup;
}
SetPageUptodate(q_page);
- pointers[rbio->real_stripes - 1] = kmap(q_page);
+ pointers[rbio->real_stripes - 1] = kmap_local_page(q_page);
}
atomic_set(&rbio->error, 0);
/* map the parity stripe just once */
- pointers[nr_data] = kmap(p_page);
+ pointers[nr_data] = kmap_local_page(p_page);
for_each_set_bit(pagenr, rbio->dbitmap, rbio->stripe_npages) {
struct page *p;
@@ -2376,7 +2375,7 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
/* first collect one page from each data stripe */
for (stripe = 0; stripe < nr_data; stripe++) {
p = page_in_rbio(rbio, stripe, pagenr, 0);
- pointers[stripe] = kmap(p);
+ pointers[stripe] = kmap_local_page(p);
}
if (has_qstripe) {
@@ -2399,14 +2398,14 @@ static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
bitmap_clear(rbio->dbitmap, pagenr, 1);
kunmap_local(parity);
- for (stripe = 0; stripe < nr_data; stripe++)
- kunmap(page_in_rbio(rbio, stripe, pagenr, 0));
+ for (stripe = nr_data - 1; stripe >= 0; stripe--)
+ kunmap_local(pointers[stripe]);
}
- kunmap(p_page);
+ kunmap_local(pointers[nr_data]);
__free_page(p_page);
if (q_page) {
- kunmap(q_page);
+ kunmap_local(pointers[rbio->real_stripes - 1]);
__free_page(q_page);
}
--
2.28.0.rc0.12.gb6a658bd00c9
^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH 2/4] fs/btrfs: Convert raid5/6 kmaps to kmap_local_page()
2021-02-17 2:48 ` [PATCH 2/4] fs/btrfs: Convert raid5/6 kmaps to kmap_local_page() ira.weiny
@ 2021-03-12 19:26 ` David Sterba
0 siblings, 0 replies; 14+ messages in thread
From: David Sterba @ 2021-03-12 19:26 UTC (permalink / raw)
To: ira.weiny; +Cc: Chris Mason, Josef Bacik, linux-kernel, linux-fsdevel
On Tue, Feb 16, 2021 at 06:48:24PM -0800, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
>
> These kmaps are thread local and don't need to be atomic. So they can use
> the more efficient kmap_local_page(). However, the mapping of pages in
> the stripes and the additional parity and qstripe pages are a bit
> trickier because the unmapping must occur in the opposite order from the
> mapping. Furthermore, the pointer array in __raid_recover_end_io() may
> get reordered.
>
> Convert these calls to kmap_local_page() taking care to reverse the
> unmappings of any page arrays as well as being careful with the mappings
> of any special pages such as the parity and qstripe pages.
Though there's one more allocation for the additional array, I don't see
a simpler way to avoid it and track the array reordering at a lower
memory cost. At least it's not in a performance critical code and the
array size is reasonably small.
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH 3/4] fs/btrfs: Use kmap_local_page() in __btrfsic_submit_bio()
2021-02-17 2:48 [PATCH 0/4] btrfs: Convert more kmaps to kmap_local_page() ira.weiny
2021-02-17 2:48 ` [PATCH 1/4] fs/btrfs: Convert kmap to kmap_local_page() using coccinelle ira.weiny
2021-02-17 2:48 ` [PATCH 2/4] fs/btrfs: Convert raid5/6 kmaps to kmap_local_page() ira.weiny
@ 2021-02-17 2:48 ` ira.weiny
2021-02-17 2:48 ` [PATCH 4/4] fs/btrfs: Convert block context kmap's to kmap_local_page() ira.weiny
` (2 subsequent siblings)
5 siblings, 0 replies; 14+ messages in thread
From: ira.weiny @ 2021-02-17 2:48 UTC (permalink / raw)
To: David Sterba
Cc: Ira Weiny, Chris Mason, Josef Bacik, linux-kernel, linux-fsdevel
From: Ira Weiny <ira.weiny@intel.com>
Again there is an array of pointers which must be unmapped in the correct
order.
Convert the kmap()'s to kmap_local_page() and adjust the unmapping
to work backwards through the unmapping loop.
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
fs/btrfs/check-integrity.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 6ff44e53814c..726eb894be8b 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -2677,7 +2677,7 @@ static void __btrfsic_submit_bio(struct bio *bio)
dev_state = btrfsic_dev_state_lookup(bio_dev(bio) + bio->bi_partno);
if (NULL != dev_state &&
(bio_op(bio) == REQ_OP_WRITE) && bio_has_data(bio)) {
- unsigned int i = 0;
+ int i = 0;
u64 dev_bytenr;
u64 cur_bytenr;
struct bio_vec bvec;
@@ -2702,7 +2702,7 @@ static void __btrfsic_submit_bio(struct bio *bio)
bio_for_each_segment(bvec, bio, iter) {
BUG_ON(bvec.bv_len != PAGE_SIZE);
- mapped_datav[i] = kmap(bvec.bv_page);
+ mapped_datav[i] = kmap_local_page(bvec.bv_page);
i++;
if (dev_state->state->print_mask &
@@ -2715,8 +2715,8 @@ static void __btrfsic_submit_bio(struct bio *bio)
mapped_datav, segs,
bio, &bio_is_patched,
bio->bi_opf);
- bio_for_each_segment(bvec, bio, iter)
- kunmap(bvec.bv_page);
+ for (--i; i >= 0; i--)
+ kunmap_local(mapped_datav[i]);
kfree(mapped_datav);
} else if (NULL != dev_state && (bio->bi_opf & REQ_PREFLUSH)) {
if (dev_state->state->print_mask &
--
2.28.0.rc0.12.gb6a658bd00c9
^ permalink raw reply related [flat|nested] 14+ messages in thread
* [PATCH 4/4] fs/btrfs: Convert block context kmap's to kmap_local_page()
2021-02-17 2:48 [PATCH 0/4] btrfs: Convert more kmaps to kmap_local_page() ira.weiny
` (2 preceding siblings ...)
2021-02-17 2:48 ` [PATCH 3/4] fs/btrfs: Use kmap_local_page() in __btrfsic_submit_bio() ira.weiny
@ 2021-02-17 2:48 ` ira.weiny
2021-03-11 21:30 ` [PATCH 0/4] btrfs: Convert more kmaps " Ira Weiny
2021-03-12 19:41 ` David Sterba
5 siblings, 0 replies; 14+ messages in thread
From: ira.weiny @ 2021-02-17 2:48 UTC (permalink / raw)
To: David Sterba
Cc: Ira Weiny, Chris Mason, Josef Bacik, linux-kernel, linux-fsdevel
From: Ira Weiny <ira.weiny@intel.com>
btrfsic_read_block() (which calls kmap()) and
btrfsic_release_block_ctx() (which calls kunmap()) are always called
within a single thread of execution.
Therefore the mappings created within these calls can be a thread local
mapping.
Convert the kmap() of bloc_ctx->pagev to kmap_local_page(). Luckily the
unmap loops backwards through the array pointer so no adjustment needs
to be made to the unmapping order.
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
fs/btrfs/check-integrity.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index 726eb894be8b..1ff9e19508a7 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -1558,7 +1558,7 @@ static void btrfsic_release_block_ctx(struct btrfsic_block_data_ctx *block_ctx)
while (num_pages > 0) {
num_pages--;
if (block_ctx->datav[num_pages]) {
- kunmap(block_ctx->pagev[num_pages]);
+ kunmap_local(block_ctx->datav[num_pages]);
block_ctx->datav[num_pages] = NULL;
}
if (block_ctx->pagev[num_pages]) {
@@ -1637,7 +1637,7 @@ static int btrfsic_read_block(struct btrfsic_state *state,
i = j;
}
for (i = 0; i < num_pages; i++)
- block_ctx->datav[i] = kmap(block_ctx->pagev[i]);
+ block_ctx->datav[i] = kmap_local_page(block_ctx->pagev[i]);
return block_ctx->len;
}
--
2.28.0.rc0.12.gb6a658bd00c9
^ permalink raw reply related [flat|nested] 14+ messages in thread
* Re: [PATCH 0/4] btrfs: Convert more kmaps to kmap_local_page()
2021-02-17 2:48 [PATCH 0/4] btrfs: Convert more kmaps to kmap_local_page() ira.weiny
` (3 preceding siblings ...)
2021-02-17 2:48 ` [PATCH 4/4] fs/btrfs: Convert block context kmap's to kmap_local_page() ira.weiny
@ 2021-03-11 21:30 ` Ira Weiny
2021-03-12 19:41 ` David Sterba
5 siblings, 0 replies; 14+ messages in thread
From: Ira Weiny @ 2021-03-11 21:30 UTC (permalink / raw)
To: David Sterba; +Cc: Chris Mason, Josef Bacik, linux-kernel, linux-fsdevel
On Tue, Feb 16, 2021 at 06:48:22PM -0800, 'Ira Weiny' wrote:
> From: Ira Weiny <ira.weiny@intel.com>
>
> I am submitting these for 5.13.
Just a friendly ping on this set.
Ira
>
> Further work to remove more kmap() calls in favor of the kmap_local_page() this
> series converts those calls which required more than a common pattern which
> were covered in my previous series[1]. This is the second of what I hope to be
> 3 series to fully convert btrfs. However, the 3rd series is going to be an RFC
> because I need to have more eyes on it before I'm sure about what to do. For
> now this series should be good to go for 5.13.
>
> Also this series converts the kmaps in the raid5/6 code which required a fix to
> the kmap'ings which was submitted in [2].
>
> Thanks,
> Ira
>
> [1] https://lore.kernel.org/lkml/20210210062221.3023586-1-ira.weiny@intel.com/
> [2] https://lore.kernel.org/lkml/20210205163943.GD5033@iweiny-DESK2.sc.intel.com/
>
>
> Ira Weiny (4):
> fs/btrfs: Convert kmap to kmap_local_page() using coccinelle
> fs/btrfs: Convert raid5/6 kmaps to kmap_local_page()
> fs/btrfs: Use kmap_local_page() in __btrfsic_submit_bio()
> fs/btrfs: Convert block context kmap's to kmap_local_page()
>
> fs/btrfs/check-integrity.c | 12 ++++----
> fs/btrfs/compression.c | 4 +--
> fs/btrfs/inode.c | 4 +--
> fs/btrfs/lzo.c | 9 +++---
> fs/btrfs/raid56.c | 61 +++++++++++++++++++-------------------
> 5 files changed, 44 insertions(+), 46 deletions(-)
>
> --
> 2.28.0.rc0.12.gb6a658bd00c9
>
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 0/4] btrfs: Convert more kmaps to kmap_local_page()
2021-02-17 2:48 [PATCH 0/4] btrfs: Convert more kmaps to kmap_local_page() ira.weiny
` (4 preceding siblings ...)
2021-03-11 21:30 ` [PATCH 0/4] btrfs: Convert more kmaps " Ira Weiny
@ 2021-03-12 19:41 ` David Sterba
2021-03-12 20:05 ` Ira Weiny
5 siblings, 1 reply; 14+ messages in thread
From: David Sterba @ 2021-03-12 19:41 UTC (permalink / raw)
To: ira.weiny; +Cc: Chris Mason, Josef Bacik, linux-kernel, linux-fsdevel
On Tue, Feb 16, 2021 at 06:48:22PM -0800, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
>
> I am submitting these for 5.13.
>
> Further work to remove more kmap() calls in favor of the kmap_local_page() this
> series converts those calls which required more than a common pattern which
> were covered in my previous series[1]. This is the second of what I hope to be
> 3 series to fully convert btrfs. However, the 3rd series is going to be an RFC
> because I need to have more eyes on it before I'm sure about what to do. For
> now this series should be good to go for 5.13.
>
> Also this series converts the kmaps in the raid5/6 code which required a fix to
> the kmap'ings which was submitted in [2].
Branch added to for-next and will be moved to the devel queue next week.
I've added some comments about the ordering requirement, that's
something not obvious. There's a comment under 1st patch but that's
trivial to fix if needed. Thanks.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 0/4] btrfs: Convert more kmaps to kmap_local_page()
2021-03-12 19:41 ` David Sterba
@ 2021-03-12 20:05 ` Ira Weiny
2021-03-16 11:07 ` David Sterba
0 siblings, 1 reply; 14+ messages in thread
From: Ira Weiny @ 2021-03-12 20:05 UTC (permalink / raw)
To: dsterba, Chris Mason, Josef Bacik, linux-kernel, linux-fsdevel
On Fri, Mar 12, 2021 at 08:41:41PM +0100, David Sterba wrote:
> On Tue, Feb 16, 2021 at 06:48:22PM -0800, ira.weiny@intel.com wrote:
> > From: Ira Weiny <ira.weiny@intel.com>
> >
> > I am submitting these for 5.13.
> >
> > Further work to remove more kmap() calls in favor of the kmap_local_page() this
> > series converts those calls which required more than a common pattern which
> > were covered in my previous series[1]. This is the second of what I hope to be
> > 3 series to fully convert btrfs. However, the 3rd series is going to be an RFC
> > because I need to have more eyes on it before I'm sure about what to do. For
> > now this series should be good to go for 5.13.
> >
> > Also this series converts the kmaps in the raid5/6 code which required a fix to
> > the kmap'ings which was submitted in [2].
>
> Branch added to for-next and will be moved to the devel queue next week.
> I've added some comments about the ordering requirement, that's
> something not obvious. There's a comment under 1st patch but that's
> trivial to fix if needed. Thanks.
I've replied to the first patch. LMK if you want me to respin it.
Thanks!
Ira
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 0/4] btrfs: Convert more kmaps to kmap_local_page()
2021-03-12 20:05 ` Ira Weiny
@ 2021-03-16 11:07 ` David Sterba
2021-03-16 16:56 ` Ira Weiny
0 siblings, 1 reply; 14+ messages in thread
From: David Sterba @ 2021-03-16 11:07 UTC (permalink / raw)
To: Ira Weiny; +Cc: dsterba, Chris Mason, Josef Bacik, linux-kernel, linux-fsdevel
On Fri, Mar 12, 2021 at 12:05:00PM -0800, Ira Weiny wrote:
> On Fri, Mar 12, 2021 at 08:41:41PM +0100, David Sterba wrote:
> > On Tue, Feb 16, 2021 at 06:48:22PM -0800, ira.weiny@intel.com wrote:
> > > From: Ira Weiny <ira.weiny@intel.com>
> > >
> > > I am submitting these for 5.13.
> > >
> > > Further work to remove more kmap() calls in favor of the kmap_local_page() this
> > > series converts those calls which required more than a common pattern which
> > > were covered in my previous series[1]. This is the second of what I hope to be
> > > 3 series to fully convert btrfs. However, the 3rd series is going to be an RFC
> > > because I need to have more eyes on it before I'm sure about what to do. For
> > > now this series should be good to go for 5.13.
> > >
> > > Also this series converts the kmaps in the raid5/6 code which required a fix to
> > > the kmap'ings which was submitted in [2].
> >
> > Branch added to for-next and will be moved to the devel queue next week.
> > I've added some comments about the ordering requirement, that's
> > something not obvious. There's a comment under 1st patch but that's
> > trivial to fix if needed. Thanks.
>
> I've replied to the first patch. LMK if you want me to respin it.
No need to respin, patchset now in misc-next. Thanks.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH 0/4] btrfs: Convert more kmaps to kmap_local_page()
2021-03-16 11:07 ` David Sterba
@ 2021-03-16 16:56 ` Ira Weiny
0 siblings, 0 replies; 14+ messages in thread
From: Ira Weiny @ 2021-03-16 16:56 UTC (permalink / raw)
To: dsterba, Chris Mason, Josef Bacik, linux-kernel, linux-fsdevel
On Tue, Mar 16, 2021 at 12:07:24PM +0100, David Sterba wrote:
> On Fri, Mar 12, 2021 at 12:05:00PM -0800, Ira Weiny wrote:
> > On Fri, Mar 12, 2021 at 08:41:41PM +0100, David Sterba wrote:
> > > On Tue, Feb 16, 2021 at 06:48:22PM -0800, ira.weiny@intel.com wrote:
> > > > From: Ira Weiny <ira.weiny@intel.com>
> > > >
> > > > I am submitting these for 5.13.
> > > >
> > > > Further work to remove more kmap() calls in favor of the kmap_local_page() this
> > > > series converts those calls which required more than a common pattern which
> > > > were covered in my previous series[1]. This is the second of what I hope to be
> > > > 3 series to fully convert btrfs. However, the 3rd series is going to be an RFC
> > > > because I need to have more eyes on it before I'm sure about what to do. For
> > > > now this series should be good to go for 5.13.
> > > >
> > > > Also this series converts the kmaps in the raid5/6 code which required a fix to
> > > > the kmap'ings which was submitted in [2].
> > >
> > > Branch added to for-next and will be moved to the devel queue next week.
> > > I've added some comments about the ordering requirement, that's
> > > something not obvious. There's a comment under 1st patch but that's
> > > trivial to fix if needed. Thanks.
> >
> > I've replied to the first patch. LMK if you want me to respin it.
>
> No need to respin, patchset now in misc-next. Thanks.
Sweet! Thanks!
Ira
^ permalink raw reply [flat|nested] 14+ messages in thread