Message ID | 20191204172804.6589-1-hch@lst.de (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | xfs: fix sub-page uptodate handling | expand |
On Wed, Dec 04, 2019 at 06:28:04PM +0100, Christoph Hellwig wrote: > bio complentions 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> Looks sane, similar fix to previous completion issues like this. Reviewed-by: Dave Chinner <dchinner@redhat.com>
On Wed, Dec 04, 2019 at 06:28:04PM +0100, Christoph Hellwig wrote: > bio complentions 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> Looks good to me, Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> --D > --- > fs/iomap/buffered-io.c | 35 +++++++++++++++++++++++++---------- > 1 file changed, 25 insertions(+), 10 deletions(-) > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > index 512856a88106..340c15400423 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -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) { > - 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); > } > > -- > 2.20.1 >
Btw, the subject should say iomap instead of xfs, sorry.
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index 512856a88106..340c15400423 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -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) { - 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); }
bio complentions 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> --- fs/iomap/buffered-io.c | 35 +++++++++++++++++++++++++---------- 1 file changed, 25 insertions(+), 10 deletions(-)