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Message-ID: <7fb4bb5a-adc7-5914-3aae-179dd8f3adb1@huawei.com>
Date: Fri, 11 Sep 2020 16:27:08 +0800
From: "yukuai (C)" <yukuai3@...wei.com>
To: Matthew Wilcox <willy@...radead.org>
CC: <hch@...radead.org>, <darrick.wong@...cle.com>,
<david@...morbit.com>, <linux-xfs@...r.kernel.org>,
<linux-fsdevel@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<yi.zhang@...wei.com>
Subject: Re: [RFC PATCH V4] iomap: add support to track dirty state of sub
pages
On 2020/08/21 20:44, Matthew Wilcox wrote:
> On Fri, Aug 21, 2020 at 08:33:06PM +0800, Yu Kuai wrote:
>> changes from v3: - add IOMAP_STATE_ARRAY_SIZE - replace set_bit /
>> clear_bit with bitmap_set / bitmap_clear - move
>> iomap_set_page_dirty() out of 'iop->state_lock' - merge
>> iomap_set/clear_range_dirty() and
>> iomap_iop_clear/clear_range_dirty()
>
> I'm still working on the iomap parts of the THP series (fixing up
> invalidatepage right now), but here are some of the relevant bits
> (patch series to follow)
>
Hi, Matthew
Since your THP iomap patches were reviewed, I made some modifications
based on these patches.
Best regards,
Yu Kuai
---
fs/iomap/buffered-io.c | 92 +++++++++++++++++++++++++++++++++---------
1 file changed, 74 insertions(+), 18 deletions(-)
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index edf5eea56cf5..bc7f57748be8 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -23,13 +23,17 @@
/*
* Structure allocated for each page or THP when block size < page size
- * to track sub-page uptodate status and I/O completions.
+ * to track sub-page status and I/O completions.
*/
struct iomap_page {
atomic_t read_bytes_pending;
atomic_t write_bytes_pending;
- spinlock_t uptodate_lock;
- unsigned long uptodate[];
+ spinlock_t state_lock;
+ /*
+ * The first half bits are used to track sub-page uptodate status,
+ * the second half bits are for dirty status.
+ */
+ unsigned long state[];
};
static inline struct iomap_page *to_iomap_page(struct page *page)
@@ -57,9 +61,9 @@ iomap_page_create(struct inode *inode, struct page *page)
if (iop || nr_blocks <= 1)
return iop;
- iop = kzalloc(struct_size(iop, uptodate, BITS_TO_LONGS(nr_blocks)),
+ iop = kzalloc(struct_size(iop, state, BITS_TO_LONGS(2 * nr_blocks)),
GFP_NOFS | __GFP_NOFAIL);
- spin_lock_init(&iop->uptodate_lock);
+ spin_lock_init(&iop->state_lock);
attach_page_private(page, iop);
return iop;
}
@@ -74,7 +78,7 @@ iomap_page_release(struct page *page)
return;
WARN_ON_ONCE(atomic_read(&iop->read_bytes_pending));
WARN_ON_ONCE(atomic_read(&iop->write_bytes_pending));
- WARN_ON_ONCE(bitmap_full(iop->uptodate, nr_blocks) !=
+ WARN_ON_ONCE(bitmap_full(iop->state, nr_blocks) !=
PageUptodate(page));
kfree(iop);
}
@@ -105,7 +109,7 @@ iomap_adjust_read_range(struct inode *inode, struct
iomap_page *iop,
/* move forward for each leading block marked uptodate */
for (i = first; i <= last; i++) {
- if (!test_bit(i, iop->uptodate))
+ if (!test_bit(i, iop->state))
break;
*pos += block_size;
poff += block_size;
@@ -115,7 +119,7 @@ iomap_adjust_read_range(struct inode *inode, struct
iomap_page *iop,
/* truncate len if we find any trailing uptodate block(s) */
for ( ; i <= last; i++) {
- if (test_bit(i, iop->uptodate)) {
+ if (test_bit(i, iop->state)) {
plen -= (last - i + 1) * block_size;
last = i - 1;
break;
@@ -139,6 +143,55 @@ iomap_adjust_read_range(struct inode *inode, struct
iomap_page *iop,
*lenp = plen;
}
+static void
+iomap_set_range_dirty(struct page *page, unsigned int off,
+ unsigned int len)
+{
+ struct inode *inode = page->mapping->host;
+ unsigned int blocks_per_page = i_blocks_per_page(inode, page);
+ unsigned int first = (off >> inode->i_blkbits) + blocks_per_page;
+ unsigned int last = ((off + len - 1) >> inode->i_blkbits) +
blocks_per_page;
+ unsigned long flags;
+ struct iomap_page *iop;
+
+ if (PageError(page))
+ return;
+
+ if (len)
+ iomap_set_page_dirty(page);
+
+ if (!page_has_private(page))
+ return;
+
+ iop = to_iomap_page(page);
+ spin_lock_irqsave(&iop->state_lock, flags);
+ bitmap_set(iop->state, first, last - first + 1);
+ spin_unlock_irqrestore(&iop->state_lock, flags);
+}
+
+static void
+iomap_clear_range_dirty(struct page *page, unsigned int off,
+ unsigned int len)
+{
+ struct inode *inode = page->mapping->host;
+ unsigned int blocks_per_page = i_blocks_per_page(inode, page);
+ unsigned int first = (off >> inode->i_blkbits) + blocks_per_page;
+ unsigned int last = ((off + len - 1) >> inode->i_blkbits) +
blocks_per_page;
+ unsigned long flags;
+ struct iomap_page *iop;
+
+ if (PageError(page))
+ return;
+
+ if (!page_has_private(page))
+ return;
+
+ iop = to_iomap_page(page);
+ spin_lock_irqsave(&iop->state_lock, flags);
+ bitmap_clear(iop->state, first, last - first + 1);
+ spin_unlock_irqrestore(&iop->state_lock, flags);
+}
+
static void
iomap_iop_set_range_uptodate(struct page *page, unsigned off, unsigned
len)
{
@@ -148,11 +201,11 @@ iomap_iop_set_range_uptodate(struct page *page,
unsigned off, unsigned len)
unsigned last = (off + len - 1) >> inode->i_blkbits;
unsigned long flags;
- spin_lock_irqsave(&iop->uptodate_lock, flags);
- bitmap_set(iop->uptodate, first, last - first + 1);
- if (bitmap_full(iop->uptodate, i_blocks_per_page(inode, page)))
+ spin_lock_irqsave(&iop->state_lock, flags);
+ bitmap_set(iop->state, first, last - first + 1);
+ if (bitmap_full(iop->state, i_blocks_per_page(inode, page)))
SetPageUptodate(page);
- spin_unlock_irqrestore(&iop->uptodate_lock, flags);
+ spin_unlock_irqrestore(&iop->state_lock, flags);
}
static void
@@ -445,7 +498,7 @@ iomap_is_partially_uptodate(struct page *page,
unsigned long from,
if (iop) {
for (i = first; i <= last; i++)
- if (!test_bit(i, iop->uptodate))
+ if (!test_bit(i, iop->state))
return 0;
return 1;
}
@@ -683,7 +736,7 @@ static size_t __iomap_write_end(struct inode *inode,
loff_t pos, size_t len,
if (unlikely(copied < len && !PageUptodate(page)))
return 0;
iomap_set_range_uptodate(page, offset_in_page(pos), len);
- iomap_set_page_dirty(page);
+ iomap_set_range_dirty(page, offset_in_page(pos), len);
return copied;
}
@@ -997,7 +1050,6 @@ iomap_page_mkwrite_actor(struct inode *inode,
loff_t pos, loff_t length,
} else {
WARN_ON_ONCE(!PageUptodate(page));
iomap_page_create(inode, page);
- set_page_dirty(page);
}
return length;
@@ -1007,7 +1059,7 @@ vm_fault_t iomap_page_mkwrite(struct vm_fault
*vmf, const struct iomap_ops *ops)
{
struct page *page = vmf->page;
struct inode *inode = file_inode(vmf->vma->vm_file);
- unsigned long length;
+ unsigned int length, dirty_bits;
loff_t offset;
ssize_t ret;
@@ -1016,6 +1068,7 @@ vm_fault_t iomap_page_mkwrite(struct vm_fault
*vmf, const struct iomap_ops *ops)
if (ret < 0)
goto out_unlock;
length = ret;
+ dirty_bits = ret;
offset = page_offset(page);
while (length > 0) {
@@ -1028,6 +1081,7 @@ vm_fault_t iomap_page_mkwrite(struct vm_fault
*vmf, const struct iomap_ops *ops)
length -= ret;
}
+ iomap_set_range_dirty(page, 0, dirty_bits);
wait_for_stable_page(page);
return VM_FAULT_LOCKED;
out_unlock:
@@ -1340,11 +1394,12 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc,
struct iomap_page *iop = to_iomap_page(page);
struct iomap_ioend *ioend, *next;
unsigned len = i_blocksize(inode);
+ unsigned int blocks_per_page = i_blocks_per_page(inode, page);
u64 file_offset; /* file offset of page */
int error = 0, count = 0, i;
LIST_HEAD(submit_list);
- WARN_ON_ONCE(i_blocks_per_page(inode, page) > 1 && !iop);
+ WARN_ON_ONCE(blocks_per_page > 1 && !iop);
WARN_ON_ONCE(iop && atomic_read(&iop->write_bytes_pending) != 0);
/*
@@ -1355,7 +1410,7 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc,
for (i = 0, file_offset = page_offset(page);
i < (PAGE_SIZE >> inode->i_blkbits) && file_offset < end_offset;
i++, file_offset += len) {
- if (iop && !test_bit(i, iop->uptodate))
+ if (iop && !test_bit(i, iop->state + blocks_per_page))
continue;
error = wpc->ops->map_blocks(wpc, inode, file_offset);
@@ -1404,6 +1459,7 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc,
*/
set_page_writeback_keepwrite(page);
} else {
+ iomap_clear_range_dirty(page, 0, PAGE_SIZE);
clear_page_dirty_for_io(page);
set_page_writeback(page);
}
--
2.25.4
.
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