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iomap: fix sub-page uptodate handling 

bio completions can race when a page spans more than one file system
block.  Add a spinlock to synchronize marking the page uptodate.

Fixes: 9dc55f1389 ("iomap: add support for sub-pagesize buffered I/O without buffer heads")
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Christoph Hellwig 2019-12-04 09:33:52 -08:00 committed by Darrick J. Wong
parent 88cfd30e18
commit 1cea335d1d
1 changed files with 25 additions and 10 deletions
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23
fs/iomap/buffered-io.c
View File

@ -28,6 +28,7 @@
struct iomap_page {
atomic_t read_count;
atomic_t write_count;
spinlock_t uptodate_lock;
DECLARE_BITMAP(uptodate, PAGE_SIZE / 512);
};
@ -51,6 +52,7 @@ iomap_page_create(struct inode *inode, struct page *page)
iop = kmalloc(sizeof(*iop), GFP_NOFS | __GFP_NOFAIL);
atomic_set(&iop->read_count, 0);
atomic_set(&iop->write_count, 0);
spin_lock_init(&iop->uptodate_lock);
bitmap_zero(iop->uptodate, PAGE_SIZE / SECTOR_SIZE);
/*
@ -139,25 +141,38 @@ iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop,
}
static void
iomap_set_range_uptodate(struct page *page, unsigned off, unsigned len)
iomap_iop_set_range_uptodate(struct page *page, unsigned off, unsigned len)
{
struct iomap_page *iop = to_iomap_page(page);
struct inode *inode = page->mapping->host;
unsigned first = off >> inode->i_blkbits;
unsigned last = (off + len - 1) >> inode->i_blkbits;
unsigned int i;
bool uptodate = true;
unsigned long flags;
unsigned int i;
if (iop) {
spin_lock_irqsave(&iop->uptodate_lock, flags);
for (i = 0; i < PAGE_SIZE / i_blocksize(inode); i++) {
if (i >= first && i <= last)
set_bit(i, iop->uptodate);
else if (!test_bit(i, iop->uptodate))
uptodate = false;
}
if (uptodate)
SetPageUptodate(page);
spin_unlock_irqrestore(&iop->uptodate_lock, flags);
}
if (uptodate && !PageError(page))
static void
iomap_set_range_uptodate(struct page *page, unsigned off, unsigned len)
{
if (PageError(page))
return;
if (page_has_private(page))
iomap_iop_set_range_uptodate(page, off, len);
else
SetPageUptodate(page);
}