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iomap: Support inline data with block size < page size

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Remove the restriction that inline data must start on a page boundary
in a file.  This allows, for example, the first 2KiB to be stored out
of line and the trailing 30 bytes to be stored inline.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2021-08-02 14:45:57 -07:00 committed by Darrick J. Wong
parent 69f4a26c1e
commit b405435b41
1 changed files with 16 additions and 18 deletions
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34
fs/iomap/buffered-io.c
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@ -209,28 +209,26 @@ static int iomap_read_inline_data(struct inode *inode, struct page *page,
struct iomap *iomap)
{
size_t size = i_size_read(inode) - iomap->offset;
size_t poff = offset_in_page(iomap->offset);
void *addr;
if (PageUptodate(page))
return 0;
return PAGE_SIZE - poff;
/* inline data must start page aligned in the file */
if (WARN_ON_ONCE(offset_in_page(iomap->offset)))
return -EIO;
if (WARN_ON_ONCE(size > PAGE_SIZE -
offset_in_page(iomap->inline_data)))
return -EIO;
if (WARN_ON_ONCE(size > iomap->length))
return -EIO;
if (WARN_ON_ONCE(page_has_private(page)))
return -EIO;
if (poff > 0)
iomap_page_create(inode, page);
addr = kmap_atomic(page);
addr = kmap_atomic(page) + poff;
memcpy(addr, iomap->inline_data, size);
memset(addr + size, 0, PAGE_SIZE - size);
memset(addr + size, 0, PAGE_SIZE - poff - size);
kunmap_atomic(addr);
SetPageUptodate(page);
return 0;
iomap_set_range_uptodate(page, poff, PAGE_SIZE - poff);
return PAGE_SIZE - poff;
}
static inline bool iomap_block_needs_zeroing(struct inode *inode,
@ -252,13 +250,8 @@ iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data,
unsigned poff, plen;
sector_t sector;
if (iomap->type == IOMAP_INLINE) {
int ret = iomap_read_inline_data(inode, page, iomap);
if (ret)
return ret;
return PAGE_SIZE;
}
if (iomap->type == IOMAP_INLINE)
return iomap_read_inline_data(inode, page, iomap);
/* zero post-eof blocks as the page may be mapped */
iop = iomap_page_create(inode, page);
@ -593,10 +586,15 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, int flags,
static int iomap_write_begin_inline(struct inode *inode,
struct page *page, struct iomap *srcmap)
{
int ret;
/* needs more work for the tailpacking case; disable for now */
if (WARN_ON_ONCE(srcmap->offset != 0))
return -EIO;
return iomap_read_inline_data(inode, page, srcmap);
ret = iomap_read_inline_data(inode, page, srcmap);
if (ret < 0)
return ret;
return 0;
}
static int