From: Christoph Hellwig hch@lst.de

commit 1cea335d1db1ce6ab71b3d2f94a807112b738a0f upstream

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

Fixes: 9dc55f1389f9 ("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 --- fs/iomap/buffered-io.c | 34 ++++++++++++++++++++++++---------- include/linux/iomap.h | 1 + 2 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 80867a1a94f2..5c73751adb2d 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -30,6 +30,7 @@ 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);

/* @@ -118,25 +119,38 @@ 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) { - 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; - } + 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 && !PageError(page)) + if (uptodate) + SetPageUptodate(page); + spin_unlock_irqrestore(&iop->uptodate_lock, flags); +} + +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); }

diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 7aa5d6117936..53b16f104081 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -139,6 +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; + spinlock_t uptodate_lock; DECLARE_BITMAP(uptodate, PAGE_SIZE / 512); };