diff options
| -rw-r--r-- | fs/buffer.c | 25 | ||||
| -rw-r--r-- | fs/fs-writeback.c | 37 | ||||
| -rw-r--r-- | fs/mpage.c | 2 | ||||
| -rw-r--r-- | include/linux/backing-dev.h | 12 | ||||
| -rw-r--r-- | include/linux/writeback.h | 68 | ||||
| -rw-r--r-- | mm/filemap.c | 2 |
6 files changed, 118 insertions, 28 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index b85e94134ea6..d883c799fb45 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -45,9 +45,9 @@ #include <trace/events/block.h> static int fsync_buffers_list(spinlock_t *lock, struct list_head *list); -static int submit_bh_blkcg(int rw, struct buffer_head *bh, - unsigned long bio_flags, - struct cgroup_subsys_state *blkcg_css); +static int submit_bh_wbc(int rw, struct buffer_head *bh, + unsigned long bio_flags, + struct writeback_control *wbc); #define BH_ENTRY(list) list_entry((list), struct buffer_head, b_assoc_buffers) @@ -1709,7 +1709,6 @@ static int __block_write_full_page(struct inode *inode, struct page *page, unsigned int blocksize, bbits; int nr_underway = 0; int write_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE); - struct cgroup_subsys_state *blkcg_css = inode_to_wb_blkcg_css(inode); head = create_page_buffers(page, inode, (1 << BH_Dirty)|(1 << BH_Uptodate)); @@ -1798,7 +1797,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page, do { struct buffer_head *next = bh->b_this_page; if (buffer_async_write(bh)) { - submit_bh_blkcg(write_op, bh, 0, blkcg_css); + submit_bh_wbc(write_op, bh, 0, wbc); nr_underway++; } bh = next; @@ -1852,7 +1851,7 @@ recover: struct buffer_head *next = bh->b_this_page; if (buffer_async_write(bh)) { clear_buffer_dirty(bh); - submit_bh_blkcg(write_op, bh, 0, blkcg_css); + submit_bh_wbc(write_op, bh, 0, wbc); nr_underway++; } bh = next; @@ -3017,11 +3016,11 @@ void guard_bio_eod(int rw, struct bio *bio) } } -static int submit_bh_blkcg(int rw, struct buffer_head *bh, - unsigned long bio_flags, - struct cgroup_subsys_state *blkcg_css) +static int submit_bh_wbc(int rw, struct buffer_head *bh, + unsigned long bio_flags, struct writeback_control *wbc) { struct bio *bio; + int ret = 0; BUG_ON(!buffer_locked(bh)); BUG_ON(!buffer_mapped(bh)); @@ -3041,8 +3040,8 @@ static int submit_bh_blkcg(int rw, struct buffer_head *bh, */ bio = bio_alloc(GFP_NOIO, 1); - if (blkcg_css) - bio_associate_blkcg(bio, blkcg_css); + if (wbc) + wbc_init_bio(wbc, bio); bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); bio->bi_bdev = bh->b_bdev; @@ -3071,13 +3070,13 @@ static int submit_bh_blkcg(int rw, struct buffer_head *bh, int _submit_bh(int rw, struct buffer_head *bh, unsigned long bio_flags) { - return submit_bh_blkcg(rw, bh, bio_flags, NULL); + return submit_bh_wbc(rw, bh, bio_flags, NULL); } EXPORT_SYMBOL_GPL(_submit_bh); int submit_bh(int rw, struct buffer_head *bh) { - return submit_bh_blkcg(rw, bh, 0, NULL); + return submit_bh_wbc(rw, bh, 0, NULL); } EXPORT_SYMBOL(submit_bh); diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index cf6ccfb01e03..755e8ef8d1f0 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -245,6 +245,37 @@ void __inode_attach_wb(struct inode *inode, struct page *page) } /** + * wbc_attach_and_unlock_inode - associate wbc with target inode and unlock it + * @wbc: writeback_control of interest + * @inode: target inode + * + * @inode is locked and about to be written back under the control of @wbc. + * Record @inode's writeback context into @wbc and unlock the i_lock. On + * writeback completion, wbc_detach_inode() should be called. This is used + * to track the cgroup writeback context. + */ +void wbc_attach_and_unlock_inode(struct writeback_control *wbc, + struct inode *inode) +{ + wbc->wb = inode_to_wb(inode); + wb_get(wbc->wb); + spin_unlock(&inode->i_lock); +} + +/** + * wbc_detach_inode - disassociate wbc from its target inode + * @wbc: writeback_control of interest + * + * To be called after a writeback attempt of an inode finishes and undoes + * wbc_attach_and_unlock_inode(). Can be called under any context. + */ +void wbc_detach_inode(struct writeback_control *wbc) +{ + wb_put(wbc->wb); + wbc->wb = NULL; +} + +/** * inode_congested - test whether an inode is congested * @inode: inode to test for congestion * @cong_bits: mask of WB_[a]sync_congested bits to test @@ -877,10 +908,11 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb, !mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK))) goto out; inode->i_state |= I_SYNC; - spin_unlock(&inode->i_lock); + wbc_attach_and_unlock_inode(wbc, inode); ret = __writeback_single_inode(inode, wbc); + wbc_detach_inode(wbc); spin_lock(&wb->list_lock); spin_lock(&inode->i_lock); /* @@ -1013,7 +1045,7 @@ static long writeback_sb_inodes(struct super_block *sb, continue; } inode->i_state |= I_SYNC; - spin_unlock(&inode->i_lock); + wbc_attach_and_unlock_inode(&wbc, inode); write_chunk = writeback_chunk_size(wb, work); wbc.nr_to_write = write_chunk; @@ -1025,6 +1057,7 @@ static long writeback_sb_inodes(struct super_block *sb, */ __writeback_single_inode(inode, &wbc); + wbc_detach_inode(&wbc); work->nr_pages -= write_chunk - wbc.nr_to_write; wrote += write_chunk - wbc.nr_to_write; spin_lock(&wb->list_lock); diff --git a/fs/mpage.c b/fs/mpage.c index a3ccb0bd465a..388fde6ac255 100644 --- a/fs/mpage.c +++ b/fs/mpage.c @@ -606,7 +606,7 @@ alloc_new: if (bio == NULL) goto confused; - bio_associate_blkcg(bio, inode_to_wb_blkcg_css(inode)); + wbc_init_bio(wbc, bio); } /* diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index 5c978a924157..b1d2489a6536 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -332,12 +332,6 @@ static inline struct bdi_writeback *inode_to_wb(struct inode *inode) return inode->i_wb; } -static inline struct cgroup_subsys_state * -inode_to_wb_blkcg_css(struct inode *inode) -{ - return inode_to_wb(inode)->blkcg_css; -} - struct wb_iter { int start_blkcg_id; struct radix_tree_iter tree_iter; @@ -434,12 +428,6 @@ static inline void wb_blkcg_offline(struct blkcg *blkcg) { } -static inline struct cgroup_subsys_state * -inode_to_wb_blkcg_css(struct inode *inode) -{ - return blkcg_root_css; -} - struct wb_iter { int next_id; }; diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 6726b7e56beb..8f964e558af5 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -86,6 +86,9 @@ struct writeback_control { unsigned for_reclaim:1; /* Invoked from the page allocator */ unsigned range_cyclic:1; /* range_start is cyclic */ unsigned for_sync:1; /* sync(2) WB_SYNC_ALL writeback */ +#ifdef CONFIG_CGROUP_WRITEBACK + struct bdi_writeback *wb; /* wb this writeback is issued under */ +#endif }; /* @@ -176,7 +179,14 @@ static inline void wait_on_inode(struct inode *inode) #ifdef CONFIG_CGROUP_WRITEBACK +#include <linux/cgroup.h> +#include <linux/bio.h> + void __inode_attach_wb(struct inode *inode, struct page *page); +void wbc_attach_and_unlock_inode(struct writeback_control *wbc, + struct inode *inode) + __releases(&inode->i_lock); +void wbc_detach_inode(struct writeback_control *wbc); /** * inode_attach_wb - associate an inode with its wb @@ -207,6 +217,44 @@ static inline void inode_detach_wb(struct inode *inode) } } +/** + * wbc_attach_fdatawrite_inode - associate wbc and inode for fdatawrite + * @wbc: writeback_control of interest + * @inode: target inode + * + * This function is to be used by __filemap_fdatawrite_range(), which is an + * alternative entry point into writeback code, and first ensures @inode is + * associated with a bdi_writeback and attaches it to @wbc. + */ +static inline void wbc_attach_fdatawrite_inode(struct writeback_control *wbc, + struct inode *inode) +{ + spin_lock(&inode->i_lock); + inode_attach_wb(inode, NULL); + wbc_attach_and_unlock_inode(wbc, inode); +} + +/** + * wbc_init_bio - writeback specific initializtion of bio + * @wbc: writeback_control for the writeback in progress + * @bio: bio to be initialized + * + * @bio is a part of the writeback in progress controlled by @wbc. Perform + * writeback specific initialization. This is used to apply the cgroup + * writeback context. + */ +static inline void wbc_init_bio(struct writeback_control *wbc, struct bio *bio) +{ + /* + * pageout() path doesn't attach @wbc to the inode being written + * out. This is intentional as we don't want the function to block + * behind a slow cgroup. Ultimately, we want pageout() to kick off + * regular writeback instead of writing things out itself. + */ + if (wbc->wb) + bio_associate_blkcg(bio, wbc->wb->blkcg_css); +} + #else /* CONFIG_CGROUP_WRITEBACK */ static inline void inode_attach_wb(struct inode *inode, struct page *page) @@ -217,6 +265,26 @@ static inline void inode_detach_wb(struct inode *inode) { } +static inline void wbc_attach_and_unlock_inode(struct writeback_control *wbc, + struct inode *inode) + __releases(&inode->i_lock) +{ + spin_unlock(&inode->i_lock); +} + +static inline void wbc_attach_fdatawrite_inode(struct writeback_control *wbc, + struct inode *inode) +{ +} + +static inline void wbc_detach_inode(struct writeback_control *wbc) +{ +} + +static inline void wbc_init_bio(struct writeback_control *wbc, struct bio *bio) +{ +} + #endif /* CONFIG_CGROUP_WRITEBACK */ /* diff --git a/mm/filemap.c b/mm/filemap.c index 7b1443dc3ad0..2f065b19b635 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -290,7 +290,9 @@ int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start, if (!mapping_cap_writeback_dirty(mapping)) return 0; + wbc_attach_fdatawrite_inode(&wbc, mapping->host); ret = do_writepages(mapping, &wbc); + wbc_detach_inode(&wbc); return ret; } |