From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Change iomap_page from a statically sized uptodate bitmap to a
dynamically allocated uptodate bitmap, allowing an arbitrarily large page.
Calculate the size of the page everywhere instead of using a base
PAGE_SIZE.
Based on a patch from Christoph Hellwig.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
fs/iomap/buffered-io.c | 82 ++++++++++++++++++++++++++----------------
include/linux/iomap.h | 2 +-
2 files changed, 53 insertions(+), 31 deletions(-)
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index e25901ae3ff4..4d56b8060b6c 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -23,14 +23,17 @@ static struct iomap_page *
iomap_page_create(struct inode *inode, struct page *page)
{
struct iomap_page *iop = to_iomap_page(page);
+ unsigned int nbits;
- if (iop || i_blocksize(inode) == PAGE_SIZE)
+ if (iop || i_blocksize(inode) == page_size(page))
return iop;
- iop = kmalloc(sizeof(*iop), GFP_NOFS | __GFP_NOFAIL);
+ nbits = BITS_TO_LONGS(page_size(page) / SECTOR_SIZE);
+ iop = kmalloc(struct_size(iop, uptodate, nbits),
+ GFP_NOFS | __GFP_NOFAIL);
atomic_set(&iop->read_count, 0);
atomic_set(&iop->write_count, 0);
- bitmap_zero(iop->uptodate, PAGE_SIZE / SECTOR_SIZE);
+ bitmap_zero(iop->uptodate, nbits);
/*
* migrate_page_move_mapping() assumes that pages with private data have
@@ -61,15 +64,16 @@ iomap_page_release(struct page *page)
* Calculate the range inside the page that we actually need to read.
*/
static void
-iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop,
+iomap_adjust_read_range(struct inode *inode, struct page *page,
loff_t *pos, loff_t length, unsigned *offp, unsigned *lenp)
{
+ struct iomap_page *iop = to_iomap_page(page);
loff_t orig_pos = *pos;
loff_t isize = i_size_read(inode);
unsigned block_bits = inode->i_blkbits;
unsigned block_size = (1 << block_bits);
- unsigned poff = offset_in_page(*pos);
- unsigned plen = min_t(loff_t, PAGE_SIZE - poff, length);
+ unsigned poff = *pos & (page_size(page) - 1);
+ unsigned plen = min_t(loff_t, page_size(page) - poff, length);
unsigned first = poff >> block_bits;
unsigned last = (poff + plen - 1) >> block_bits;
@@ -107,7 +111,8 @@ iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop,
* page cache for blocks that are entirely outside of i_size.
*/
if (orig_pos <= isize && orig_pos + length > isize) {
- unsigned end = offset_in_page(isize - 1) >> block_bits;
+ unsigned end = (isize - 1) & (page_size(page) - 1) >>
+ block_bits;
if (first <= end && last > end)
plen -= (last - end) * block_size;
@@ -128,7 +133,7 @@ iomap_set_range_uptodate(struct page *page, unsigned off, unsigned len)
bool uptodate = true;
if (iop) {
- for (i = 0; i < PAGE_SIZE / i_blocksize(inode); i++) {
+ for (i = 0; i < page_size(page) / i_blocksize(inode); i++) {
if (i >= first && i <= last)
set_bit(i, iop->uptodate);
else if (!test_bit(i, iop->uptodate))
@@ -194,11 +199,12 @@ iomap_read_inline_data(struct inode *inode, struct page *page,
return;
BUG_ON(page->index);
- BUG_ON(size > PAGE_SIZE - offset_in_page(iomap->inline_data));
+ BUG_ON(size > page_size(page) - ((unsigned long)iomap->inline_data &
+ (page_size(page) - 1)));
addr = kmap_atomic(page);
memcpy(addr, iomap->inline_data, size);
- memset(addr + size, 0, PAGE_SIZE - size);
+ memset(addr + size, 0, page_size(page) - size);
kunmap_atomic(addr);
SetPageUptodate(page);
}
@@ -218,11 +224,11 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
if (iomap->type == IOMAP_INLINE) {
WARN_ON_ONCE(pos);
iomap_read_inline_data(inode, page, iomap);
- return PAGE_SIZE;
+ return page_size(page);
}
/* zero post-eof blocks as the page may be mapped */
- iomap_adjust_read_range(inode, iop, &pos, length, &poff, &plen);
+ iomap_adjust_read_range(inode, page, &pos, length, &poff, &plen);
if (plen == 0)
goto done;
@@ -258,7 +264,7 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
if (!ctx->bio || !is_contig || bio_full(ctx->bio, plen)) {
gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);
- int nr_vecs = (length + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ int nr_vecs = (length + page_size(page) - 1) >> page_shift(page);
if (ctx->bio)
submit_bio(ctx->bio);
@@ -293,9 +299,9 @@ iomap_readpage(struct page *page, const struct iomap_ops *ops)
unsigned poff;
loff_t ret;
- for (poff = 0; poff < PAGE_SIZE; poff += ret) {
+ for (poff = 0; poff < page_size(page); poff += ret) {
ret = iomap_apply(inode, page_offset(page) + poff,
- PAGE_SIZE - poff, 0, ops, &ctx,
+ page_size(page) - poff, 0, ops, &ctx,
iomap_readpage_actor);
if (ret <= 0) {
WARN_ON_ONCE(ret == 0);
@@ -342,7 +348,7 @@ iomap_next_page(struct inode *inode, struct list_head *pages, loff_t pos,
* readpages call itself as every page gets checked again once
* actually needed.
*/
- *done += PAGE_SIZE;
+ *done += page_size(page);
put_page(page);
}
@@ -355,9 +361,14 @@ iomap_readpages_actor(struct inode *inode, loff_t pos, loff_t length,
{
struct iomap_readpage_ctx *ctx = data;
loff_t done, ret;
+ size_t pg_left = 0;
+
+ if (ctx->cur_page)
+ pg_left = page_size(ctx->cur_page) -
+ (pos & (page_size(ctx->cur_page) - 1));
for (done = 0; done < length; done += ret) {
- if (ctx->cur_page && offset_in_page(pos + done) == 0) {
+ if (ctx->cur_page && pg_left == 0) {
if (!ctx->cur_page_in_bio)
unlock_page(ctx->cur_page);
put_page(ctx->cur_page);
@@ -369,9 +380,11 @@ iomap_readpages_actor(struct inode *inode, loff_t pos, loff_t length,
if (!ctx->cur_page)
break;
ctx->cur_page_in_bio = false;
+ pg_left = page_size(ctx->cur_page);
}
ret = iomap_readpage_actor(inode, pos + done, length - done,
ctx, iomap);
+ pg_left -= ret;
}
return done;
@@ -386,8 +399,9 @@ iomap_readpages(struct address_space *mapping, struct list_head *pages,
.is_readahead = true,
};
loff_t pos = page_offset(list_entry(pages->prev, struct page, lru));
- loff_t last = page_offset(list_entry(pages->next, struct page, lru));
- loff_t length = last - pos + PAGE_SIZE, ret = 0;
+ struct page *last_page = list_entry(pages->next, struct page, lru);
+ loff_t length = page_offset(last_page) - pos + page_size(last_page);
+ loff_t ret = 0;
while (length > 0) {
ret = iomap_apply(mapping->host, pos, length, 0, ops,
@@ -435,7 +449,7 @@ iomap_is_partially_uptodate(struct page *page, unsigned long from,
unsigned i;
/* Limit range to one page */
- len = min_t(unsigned, PAGE_SIZE - from, count);
+ len = min_t(unsigned, page_size(page) - from, count);
/* First and last blocks in range within page */
first = from >> inode->i_blkbits;
@@ -474,7 +488,7 @@ iomap_invalidatepage(struct page *page, unsigned int offset, unsigned int len)
* If we are invalidating the entire page, clear the dirty state from it
* and release it to avoid unnecessary buildup of the LRU.
*/
- if (offset == 0 && len == PAGE_SIZE) {
+ if (offset == 0 && len == page_size(page)) {
WARN_ON_ONCE(PageWriteback(page));
cancel_dirty_page(page);
iomap_page_release(page);
@@ -550,18 +564,20 @@ static int
__iomap_write_begin(struct inode *inode, loff_t pos, unsigned len,
struct page *page, struct iomap *iomap)
{
- struct iomap_page *iop = iomap_page_create(inode, page);
loff_t block_size = i_blocksize(inode);
loff_t block_start = pos & ~(block_size - 1);
loff_t block_end = (pos + len + block_size - 1) & ~(block_size - 1);
- unsigned from = offset_in_page(pos), to = from + len, poff, plen;
+ unsigned from = pos & (page_size(page) - 1);
+ unsigned to = from + len;
+ unsigned poff, plen;
int status = 0;
if (PageUptodate(page))
return 0;
+ iomap_page_create(inode, page);
do {
- iomap_adjust_read_range(inode, iop, &block_start,
+ iomap_adjust_read_range(inode, page, &block_start,
block_end - block_start, &poff, &plen);
if (plen == 0)
break;
@@ -673,7 +689,7 @@ __iomap_write_end(struct inode *inode, loff_t pos, unsigned len,
*/
if (unlikely(copied < len && !PageUptodate(page)))
return 0;
- iomap_set_range_uptodate(page, offset_in_page(pos), len);
+ iomap_set_range_uptodate(page, pos & (page_size(page) - 1), len);
iomap_set_page_dirty(page);
return copied;
}
@@ -685,7 +701,9 @@ iomap_write_end_inline(struct inode *inode, struct page *page,
void *addr;
WARN_ON_ONCE(!PageUptodate(page));
- BUG_ON(pos + copied > PAGE_SIZE - offset_in_page(iomap->inline_data));
+ BUG_ON(pos + copied > page_size(page) -
+ ((unsigned long)iomap->inline_data &
+ (page_size(page) - 1)));
addr = kmap_atomic(page);
memcpy(iomap->inline_data + pos, addr + pos, copied);
@@ -749,6 +767,10 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
unsigned long bytes; /* Bytes to write to page */
size_t copied; /* Bytes copied from user */
+ /*
+ * XXX: We don't know what size page we'll find in the
+ * page cache, so only copy up to a regular page boundary.
+ */
offset = offset_in_page(pos);
bytes = min_t(unsigned long, PAGE_SIZE - offset,
iov_iter_count(i));
@@ -1047,11 +1069,11 @@ vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops)
goto out_unlock;
}
- /* page is wholly or partially inside EOF */
- if (((page->index + 1) << PAGE_SHIFT) > size)
- length = offset_in_page(size);
+ /* page is wholly or partially beyond EOF */
+ if (((page->index + compound_nr(page)) << PAGE_SHIFT) > size)
+ length = size & (page_size(page) - 1);
else
- length = PAGE_SIZE;
+ length = page_size(page);
offset = page_offset(page);
while (length > 0) {
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index bc499ceae392..86be24a8259b 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -139,7 +139,7 @@ loff_t iomap_apply(struct inode *inode, loff_t pos, loff_t length,
struct iomap_page {
atomic_t read_count;
atomic_t write_count;
- DECLARE_BITMAP(uptodate, PAGE_SIZE / 512);
+ unsigned long uptodate[];
};
static inline struct iomap_page *to_iomap_page(struct page *page)
--
2.20.1
