From ff9ea323816dc1c8ac7144afd4eab3ac97704430 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 8 Sep 2014 08:03:56 +0900 Subject: block, bdi: an active gendisk always has a request_queue associated with it bdev_get_queue() returns the request_queue associated with the specified block_device. blk_get_backing_dev_info() makes use of bdev_get_queue() to determine the associated bdi given a block_device. All the callers of bdev_get_queue() including blk_get_backing_dev_info() assume that bdev_get_queue() may return NULL and implement NULL handling; however, bdev_get_queue() requires the passed in block_device is opened and attached to its gendisk. Because an active gendisk always has a valid request_queue associated with it, bdev_get_queue() can never return NULL and neither can blk_get_backing_dev_info(). Make it clear that neither of the two functions can return NULL and remove NULL handling from all the callers. Signed-off-by: Tejun Heo Cc: Chris Mason Cc: Dave Chinner Signed-off-by: Jens Axboe --- fs/block_dev.c | 2 -- fs/btrfs/disk-io.c | 2 +- fs/xfs/xfs_buf.c | 2 -- 3 files changed, 1 insertion(+), 5 deletions(-) (limited to 'fs') diff --git a/fs/block_dev.c b/fs/block_dev.c index 6d72746..d3251ec 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1173,8 +1173,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) if (!ret) { bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); bdi = blk_get_backing_dev_info(bdev); - if (bdi == NULL) - bdi = &default_backing_dev_info; bdev_inode_switch_bdi(bdev->bd_inode, bdi); } diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index d0ed9e6..39ff591 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1694,7 +1694,7 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits) if (!device->bdev) continue; bdi = blk_get_backing_dev_info(device->bdev); - if (bdi && bdi_congested(bdi, bdi_bits)) { + if (bdi_congested(bdi, bdi_bits)) { ret = 1; break; } diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index cd7b8ca..497fcde 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -1678,8 +1678,6 @@ xfs_alloc_buftarg( btp->bt_dev = bdev->bd_dev; btp->bt_bdev = bdev; btp->bt_bdi = blk_get_backing_dev_info(bdev); - if (!btp->bt_bdi) - goto error; if (xfs_setsize_buftarg_early(btp, bdev)) goto error; -- cgit v1.1 From 018a17bdc8658ad448497c84d4ba21b6985820ec Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 8 Sep 2014 08:04:01 +0900 Subject: bdi: reimplement bdev_inode_switch_bdi() A block_device may be attached to different gendisks and thus different bdis over time. bdev_inode_switch_bdi() is used to switch the associated bdi. The function assumes that the inode could be dirty and transfers it between bdis if so. This is a bit nasty in that it reaches into bdi internals. This patch reimplements the function so that it writes out the inode if dirty. This is a lot simpler and can be implemented without exposing bdi internals. Signed-off-by: Tejun Heo Cc: Alexander Viro Signed-off-by: Jens Axboe --- fs/block_dev.c | 32 +++++++++++--------------------- 1 file changed, 11 insertions(+), 21 deletions(-) (limited to 'fs') diff --git a/fs/block_dev.c b/fs/block_dev.c index d3251ec..cc8d68a 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -50,32 +50,22 @@ inline struct block_device *I_BDEV(struct inode *inode) EXPORT_SYMBOL(I_BDEV); /* - * Move the inode from its current bdi to a new bdi. If the inode is dirty we - * need to move it onto the dirty list of @dst so that the inode is always on - * the right list. + * Move the inode from its current bdi to a new bdi. Make sure the inode + * is clean before moving so that it doesn't linger on the old bdi. */ static void bdev_inode_switch_bdi(struct inode *inode, struct backing_dev_info *dst) { - struct backing_dev_info *old = inode->i_data.backing_dev_info; - bool wakeup_bdi = false; - - if (unlikely(dst == old)) /* deadlock avoidance */ - return; - bdi_lock_two(&old->wb, &dst->wb); - spin_lock(&inode->i_lock); - inode->i_data.backing_dev_info = dst; - if (inode->i_state & I_DIRTY) { - if (bdi_cap_writeback_dirty(dst) && !wb_has_dirty_io(&dst->wb)) - wakeup_bdi = true; - list_move(&inode->i_wb_list, &dst->wb.b_dirty); + while (true) { + spin_lock(&inode->i_lock); + if (!(inode->i_state & I_DIRTY)) { + inode->i_data.backing_dev_info = dst; + spin_unlock(&inode->i_lock); + return; + } + spin_unlock(&inode->i_lock); + WARN_ON_ONCE(write_inode_now(inode, true)); } - spin_unlock(&inode->i_lock); - spin_unlock(&old->wb.list_lock); - spin_unlock(&dst->wb.list_lock); - - if (wakeup_bdi) - bdi_wakeup_thread_delayed(dst); } /* Kill _all_ buffers and pagecache , dirty or not.. */ -- cgit v1.1 From e19a8a0ad2d255316830ead05b59c5a704434cbb Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Tue, 14 Oct 2014 09:00:44 -0600 Subject: block: Remove REQ_KERNEL REQ_KERNEL is no longer used. Remove it and drop the redundant uio argument to nfs_file_direct_{read,write}. Signed-off-by: Martin K. Petersen Cc: Christoph Hellwig Reported-by: Dan Carpenter Signed-off-by: Jens Axboe --- fs/nfs/direct.c | 12 +++++------- fs/nfs/file.c | 4 ++-- 2 files changed, 7 insertions(+), 9 deletions(-) (limited to 'fs') diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 65ef6e0..891f7dd 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -222,11 +222,9 @@ ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter, loff_t #else VM_BUG_ON(iocb->ki_nbytes != PAGE_SIZE); - if (rw == READ || rw == KERNEL_READ) - return nfs_file_direct_read(iocb, iter, pos, - rw == READ ? true : false); - return nfs_file_direct_write(iocb, iter, pos, - rw == WRITE ? true : false); + if (rw == READ) + return nfs_file_direct_read(iocb, iter, pos); + return nfs_file_direct_write(iocb, iter, pos); #endif /* CONFIG_NFS_SWAP */ } @@ -512,7 +510,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, * cache. */ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter, - loff_t pos, bool uio) + loff_t pos) { struct file *file = iocb->ki_filp; struct address_space *mapping = file->f_mapping; @@ -893,7 +891,7 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq, * is no atomic O_APPEND write facility in the NFS protocol. */ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter, - loff_t pos, bool uio) + loff_t pos) { ssize_t result = -EINVAL; struct file *file = iocb->ki_filp; diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 524dd80..3b42cb8 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -171,7 +171,7 @@ nfs_file_read(struct kiocb *iocb, struct iov_iter *to) ssize_t result; if (iocb->ki_filp->f_flags & O_DIRECT) - return nfs_file_direct_read(iocb, to, iocb->ki_pos, true); + return nfs_file_direct_read(iocb, to, iocb->ki_pos); dprintk("NFS: read(%pD2, %zu@%lu)\n", iocb->ki_filp, @@ -648,7 +648,7 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from) return result; if (file->f_flags & O_DIRECT) - return nfs_file_direct_write(iocb, from, pos, true); + return nfs_file_direct_write(iocb, from, pos); dprintk("NFS: write(%pD2, %zu@%Ld)\n", file, count, (long long) pos); -- cgit v1.1