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authorLinus Torvalds <torvalds@linux-foundation.org>2015-06-25 16:00:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-25 16:00:17 -0700
commite4bc13adfd016fc1036838170288b5680d1a98b0 (patch)
tree8d2cb749397749439732f3a827cb7f2336408337 /fs
parentad90fb97515b732bc27a0109baa10af636c3c8cd (diff)
parent3e1534cf4a2a8278e811e7c84a79da1a02347b8b (diff)
Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block
Pull cgroup writeback support from Jens Axboe: "This is the big pull request for adding cgroup writeback support. This code has been in development for a long time, and it has been simmering in for-next for a good chunk of this cycle too. This is one of those problems that has been talked about for at least half a decade, finally there's a solution and code to go with it. Also see last weeks writeup on LWN: http://lwn.net/Articles/648292/" * 'for-4.2/writeback' of git://git.kernel.dk/linux-block: (85 commits) writeback, blkio: add documentation for cgroup writeback support vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB writeback: do foreign inode detection iff cgroup writeback is enabled v9fs: fix error handling in v9fs_session_init() bdi: fix wrong error return value in cgwb_create() buffer: remove unusued 'ret' variable writeback: disassociate inodes from dying bdi_writebacks writeback: implement foreign cgroup inode bdi_writeback switching writeback: add lockdep annotation to inode_to_wb() writeback: use unlocked_inode_to_wb transaction in inode_congested() writeback: implement unlocked_inode_to_wb transaction and use it for stat updates writeback: implement [locked_]inode_to_wb_and_lock_list() writeback: implement foreign cgroup inode detection writeback: make writeback_control track the inode being written back writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb() mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use writeback: implement memcg writeback domain based throttling writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes writeback: implement memcg wb_domain writeback: update wb_over_bg_thresh() to use wb_domain aware operations ...
Diffstat (limited to 'fs')
-rw-r--r--fs/9p/v9fs.c50
-rw-r--r--fs/9p/vfs_super.c8
-rw-r--r--fs/block_dev.c9
-rw-r--r--fs/buffer.c64
-rw-r--r--fs/ext2/super.c1
-rw-r--r--fs/ext4/extents.c1
-rw-r--r--fs/ext4/mballoc.c1
-rw-r--r--fs/ext4/super.c1
-rw-r--r--fs/f2fs/node.c4
-rw-r--r--fs/f2fs/segment.h3
-rw-r--r--fs/fat/file.c1
-rw-r--r--fs/fat/inode.c1
-rw-r--r--fs/fs-writeback.c1167
-rw-r--r--fs/fuse/file.c12
-rw-r--r--fs/gfs2/super.c2
-rw-r--r--fs/hfs/super.c1
-rw-r--r--fs/hfsplus/super.c1
-rw-r--r--fs/inode.c1
-rw-r--r--fs/mpage.c3
-rw-r--r--fs/nfs/filelayout/filelayout.c1
-rw-r--r--fs/nfs/internal.h2
-rw-r--r--fs/nfs/write.c3
-rw-r--r--fs/ocfs2/file.c1
-rw-r--r--fs/reiserfs/super.c1
-rw-r--r--fs/ufs/super.c1
-rw-r--r--fs/xfs/xfs_aops.c12
-rw-r--r--fs/xfs/xfs_file.c1
27 files changed, 1079 insertions, 274 deletions
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 620d93489539..8aa56bb6e861 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -320,31 +320,21 @@ fail_option_alloc:
struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
const char *dev_name, char *data)
{
- int retval = -EINVAL;
struct p9_fid *fid;
- int rc;
+ int rc = -ENOMEM;
v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
if (!v9ses->uname)
- return ERR_PTR(-ENOMEM);
+ goto err_names;
v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
- if (!v9ses->aname) {
- kfree(v9ses->uname);
- return ERR_PTR(-ENOMEM);
- }
+ if (!v9ses->aname)
+ goto err_names;
init_rwsem(&v9ses->rename_sem);
rc = bdi_setup_and_register(&v9ses->bdi, "9p");
- if (rc) {
- kfree(v9ses->aname);
- kfree(v9ses->uname);
- return ERR_PTR(rc);
- }
-
- spin_lock(&v9fs_sessionlist_lock);
- list_add(&v9ses->slist, &v9fs_sessionlist);
- spin_unlock(&v9fs_sessionlist_lock);
+ if (rc)
+ goto err_names;
v9ses->uid = INVALID_UID;
v9ses->dfltuid = V9FS_DEFUID;
@@ -352,10 +342,9 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
v9ses->clnt = p9_client_create(dev_name, data);
if (IS_ERR(v9ses->clnt)) {
- retval = PTR_ERR(v9ses->clnt);
- v9ses->clnt = NULL;
+ rc = PTR_ERR(v9ses->clnt);
p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
- goto error;
+ goto err_bdi;
}
v9ses->flags = V9FS_ACCESS_USER;
@@ -368,10 +357,8 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
}
rc = v9fs_parse_options(v9ses, data);
- if (rc < 0) {
- retval = rc;
- goto error;
- }
+ if (rc < 0)
+ goto err_clnt;
v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
@@ -405,10 +392,9 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
v9ses->aname);
if (IS_ERR(fid)) {
- retval = PTR_ERR(fid);
- fid = NULL;
+ rc = PTR_ERR(fid);
p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
- goto error;
+ goto err_clnt;
}
if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
@@ -420,12 +406,20 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
/* register the session for caching */
v9fs_cache_session_get_cookie(v9ses);
#endif
+ spin_lock(&v9fs_sessionlist_lock);
+ list_add(&v9ses->slist, &v9fs_sessionlist);
+ spin_unlock(&v9fs_sessionlist_lock);
return fid;
-error:
+err_clnt:
+ p9_client_destroy(v9ses->clnt);
+err_bdi:
bdi_destroy(&v9ses->bdi);
- return ERR_PTR(retval);
+err_names:
+ kfree(v9ses->uname);
+ kfree(v9ses->aname);
+ return ERR_PTR(rc);
}
/**
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index e99a338a4638..bf495cedec26 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -130,11 +130,7 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
fid = v9fs_session_init(v9ses, dev_name, data);
if (IS_ERR(fid)) {
retval = PTR_ERR(fid);
- /*
- * we need to call session_close to tear down some
- * of the data structure setup by session_init
- */
- goto close_session;
+ goto free_session;
}
sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses);
@@ -195,8 +191,8 @@ static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags,
clunk_fid:
p9_client_clunk(fid);
-close_session:
v9fs_session_close(v9ses);
+free_session:
kfree(v9ses);
return ERR_PTR(retval);
diff --git a/fs/block_dev.c b/fs/block_dev.c
index c7e4163ede87..f04c873a7365 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -14,6 +14,7 @@
#include <linux/device_cgroup.h>
#include <linux/highmem.h>
#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
#include <linux/module.h>
#include <linux/blkpg.h>
#include <linux/magic.h>
@@ -546,7 +547,8 @@ static struct file_system_type bd_type = {
.kill_sb = kill_anon_super,
};
-static struct super_block *blockdev_superblock __read_mostly;
+struct super_block *blockdev_superblock __read_mostly;
+EXPORT_SYMBOL_GPL(blockdev_superblock);
void __init bdev_cache_init(void)
{
@@ -687,11 +689,6 @@ static struct block_device *bd_acquire(struct inode *inode)
return bdev;
}
-int sb_is_blkdev_sb(struct super_block *sb)
-{
- return sb == blockdev_superblock;
-}
-
/* Call when you free inode */
void bd_forget(struct inode *inode)
diff --git a/fs/buffer.c b/fs/buffer.c
index f96173ad62d9..1cf7a53a0277 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -30,6 +30,7 @@
#include <linux/quotaops.h>
#include <linux/highmem.h>
#include <linux/export.h>
+#include <linux/backing-dev.h>
#include <linux/writeback.h>
#include <linux/hash.h>
#include <linux/suspend.h>
@@ -44,6 +45,9 @@
#include <trace/events/block.h>
static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
+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)
@@ -623,21 +627,22 @@ EXPORT_SYMBOL(mark_buffer_dirty_inode);
*
* If warn is true, then emit a warning if the page is not uptodate and has
* not been truncated.
+ *
+ * The caller must hold mem_cgroup_begin_page_stat() lock.
*/
-static void __set_page_dirty(struct page *page,
- struct address_space *mapping, int warn)
+static void __set_page_dirty(struct page *page, struct address_space *mapping,
+ struct mem_cgroup *memcg, int warn)
{
unsigned long flags;
spin_lock_irqsave(&mapping->tree_lock, flags);
if (page->mapping) { /* Race with truncate? */
WARN_ON_ONCE(warn && !PageUptodate(page));
- account_page_dirtied(page, mapping);
+ account_page_dirtied(page, mapping, memcg);
radix_tree_tag_set(&mapping->page_tree,
page_index(page), PAGECACHE_TAG_DIRTY);
}
spin_unlock_irqrestore(&mapping->tree_lock, flags);
- __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
}
/*
@@ -668,6 +673,7 @@ static void __set_page_dirty(struct page *page,
int __set_page_dirty_buffers(struct page *page)
{
int newly_dirty;
+ struct mem_cgroup *memcg;
struct address_space *mapping = page_mapping(page);
if (unlikely(!mapping))
@@ -683,11 +689,22 @@ int __set_page_dirty_buffers(struct page *page)
bh = bh->b_this_page;
} while (bh != head);
}
+ /*
+ * Use mem_group_begin_page_stat() to keep PageDirty synchronized with
+ * per-memcg dirty page counters.
+ */
+ memcg = mem_cgroup_begin_page_stat(page);
newly_dirty = !TestSetPageDirty(page);
spin_unlock(&mapping->private_lock);
if (newly_dirty)
- __set_page_dirty(page, mapping, 1);
+ __set_page_dirty(page, mapping, memcg, 1);
+
+ mem_cgroup_end_page_stat(memcg);
+
+ if (newly_dirty)
+ __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
+
return newly_dirty;
}
EXPORT_SYMBOL(__set_page_dirty_buffers);
@@ -1158,11 +1175,18 @@ void mark_buffer_dirty(struct buffer_head *bh)
if (!test_set_buffer_dirty(bh)) {
struct page *page = bh->b_page;
+ struct address_space *mapping = NULL;
+ struct mem_cgroup *memcg;
+
+ memcg = mem_cgroup_begin_page_stat(page);
if (!TestSetPageDirty(page)) {
- struct address_space *mapping = page_mapping(page);
+ mapping = page_mapping(page);
if (mapping)
- __set_page_dirty(page, mapping, 0);
+ __set_page_dirty(page, mapping, memcg, 0);
}
+ mem_cgroup_end_page_stat(memcg);
+ if (mapping)
+ __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
}
}
EXPORT_SYMBOL(mark_buffer_dirty);
@@ -1684,8 +1708,7 @@ static int __block_write_full_page(struct inode *inode, struct page *page,
struct buffer_head *bh, *head;
unsigned int blocksize, bbits;
int nr_underway = 0;
- int write_op = (wbc->sync_mode == WB_SYNC_ALL ?
- WRITE_SYNC : WRITE);
+ int write_op = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE);
head = create_page_buffers(page, inode,
(1 << BH_Dirty)|(1 << BH_Uptodate));
@@ -1774,7 +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(write_op, bh);
+ submit_bh_wbc(write_op, bh, 0, wbc);
nr_underway++;
}
bh = next;
@@ -1828,7 +1851,7 @@ recover:
struct buffer_head *next = bh->b_this_page;
if (buffer_async_write(bh)) {
clear_buffer_dirty(bh);
- submit_bh(write_op, bh);
+ submit_bh_wbc(write_op, bh, 0, wbc);
nr_underway++;
}
bh = next;
@@ -2993,7 +3016,8 @@ void guard_bio_eod(int rw, struct bio *bio)
}
}
-int _submit_bh(int rw, struct buffer_head *bh, unsigned long bio_flags)
+static int submit_bh_wbc(int rw, struct buffer_head *bh,
+ unsigned long bio_flags, struct writeback_control *wbc)
{
struct bio *bio;
@@ -3015,6 +3039,11 @@ int _submit_bh(int rw, struct buffer_head *bh, unsigned long bio_flags)
*/
bio = bio_alloc(GFP_NOIO, 1);
+ if (wbc) {
+ wbc_init_bio(wbc, bio);
+ wbc_account_io(wbc, bh->b_page, bh->b_size);
+ }
+
bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
bio->bi_bdev = bh->b_bdev;
bio->bi_io_vec[0].bv_page = bh->b_page;
@@ -3039,11 +3068,16 @@ int _submit_bh(int rw, struct buffer_head *bh, unsigned long bio_flags)
submit_bio(rw, bio);
return 0;
}
+
+int _submit_bh(int rw, struct buffer_head *bh, unsigned long bio_flags)
+{
+ 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(rw, bh, 0);
+ return submit_bh_wbc(rw, bh, 0, NULL);
}
EXPORT_SYMBOL(submit_bh);
@@ -3232,8 +3266,8 @@ int try_to_free_buffers(struct page *page)
* to synchronise against __set_page_dirty_buffers and prevent the
* dirty bit from being lost.
*/
- if (ret && TestClearPageDirty(page))
- account_page_cleaned(page, mapping);
+ if (ret)
+ cancel_dirty_page(page);
spin_unlock(&mapping->private_lock);
out:
if (buffers_to_free) {
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index d0e746e96511..900e19cf9ef6 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -882,6 +882,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
((EXT2_SB(sb)->s_mount_opt & EXT2_MOUNT_POSIX_ACL) ?
MS_POSIXACL : 0);
+ sb->s_iflags |= SB_I_CGROUPWB;
if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV &&
(EXT2_HAS_COMPAT_FEATURE(sb, ~0U) ||
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index d86d2622f826..aadb72828834 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -39,6 +39,7 @@
#include <linux/slab.h>
#include <asm/uaccess.h>
#include <linux/fiemap.h>
+#include <linux/backing-dev.h>
#include "ext4_jbd2.h"
#include "ext4_extents.h"
#include "xattr.h"
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 1c535fa67640..f6aedf88da43 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -26,6 +26,7 @@
#include <linux/log2.h>
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/backing-dev.h>
#include <trace/events/ext4.h>
#ifdef CONFIG_EXT4_DEBUG
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 90ec13fe8ac7..a7b4b6e10269 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -24,6 +24,7 @@
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
#include <linux/parser.h>
#include <linux/buffer_head.h>
#include <linux/exportfs.h>
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index d9c52424bac2..7dd63b794bfb 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -53,7 +53,7 @@ bool available_free_memory(struct f2fs_sb_info *sbi, int type)
PAGE_CACHE_SHIFT;
res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
} else if (type == DIRTY_DENTS) {
- if (sbi->sb->s_bdi->dirty_exceeded)
+ if (sbi->sb->s_bdi->wb.dirty_exceeded)
return false;
mem_size = get_pages(sbi, F2FS_DIRTY_DENTS);
res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
@@ -70,7 +70,7 @@ bool available_free_memory(struct f2fs_sb_info *sbi, int type)
sizeof(struct extent_node)) >> PAGE_CACHE_SHIFT;
res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
} else {
- if (sbi->sb->s_bdi->dirty_exceeded)
+ if (sbi->sb->s_bdi->wb.dirty_exceeded)
return false;
}
return res;
diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h
index 849635778118..79e7b879a753 100644
--- a/fs/f2fs/segment.h
+++ b/fs/f2fs/segment.h
@@ -9,6 +9,7 @@
* published by the Free Software Foundation.
*/
#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
/* constant macro */
#define NULL_SEGNO ((unsigned int)(~0))
@@ -714,7 +715,7 @@ static inline unsigned int max_hw_blocks(struct f2fs_sb_info *sbi)
*/
static inline int nr_pages_to_skip(struct f2fs_sb_info *sbi, int type)
{
- if (sbi->sb->s_bdi->dirty_exceeded)
+ if (sbi->sb->s_bdi->wb.dirty_exceeded)
return 0;
if (type == DATA)
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 442d50a0e33e..a08f1039909a 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -11,6 +11,7 @@
#include <linux/compat.h>
#include <linux/mount.h>
#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
#include <linux/fsnotify.h>
#include <linux/security.h>
#include "fat.h"
diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index c06774658345..509411dd3698 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -18,6 +18,7 @@
#include <linux/parser.h>
#include <linux/uio.h>
#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
#include <asm/unaligned.h>
#include "fat.h"
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 32a8bbd7a9ad..f0520bcf2094 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -27,6 +27,7 @@
#include <linux/backing-dev.h>
#include <linux/tracepoint.h>
#include <linux/device.h>
+#include <linux/memcontrol.h>
#include "internal.h"
/*
@@ -34,6 +35,10 @@
*/
#define MIN_WRITEBACK_PAGES (4096UL >> (PAGE_CACHE_SHIFT - 10))
+struct wb_completion {
+ atomic_t cnt;
+};
+
/*
* Passed into wb_writeback(), essentially a subset of writeback_control
*/
@@ -47,13 +52,29 @@ struct wb_writeback_work {
unsigned int range_cyclic:1;
unsigned int for_background:1;
unsigned int for_sync:1; /* sync(2) WB_SYNC_ALL writeback */
+ unsigned int auto_free:1; /* free on completion */
+ unsigned int single_wait:1;
+ unsigned int single_done:1;
enum wb_reason reason; /* why was writeback initiated? */
struct list_head list; /* pending work list */
- struct completion *done; /* set if the caller waits */
+ struct wb_completion *done; /* set if the caller waits */
};
/*
+ * If one wants to wait for one or more wb_writeback_works, each work's
+ * ->done should be set to a wb_completion defined using the following
+ * macro. Once all work items are issued with wb_queue_work(), the caller
+ * can wait for the completion of all using wb_wait_for_completion(). Work
+ * items which are waited upon aren't freed automatically on completion.
+ */
+#define DEFINE_WB_COMPLETION_ONSTACK(cmpl) \
+ struct wb_completion cmpl = { \
+ .cnt = ATOMIC_INIT(1), \
+ }
+
+
+/*
* If an inode is constantly having its pages dirtied, but then the
* updates stop dirtytime_expire_interval seconds in the past, it's
* possible for the worst case time between when an inode has its
@@ -65,35 +86,6 @@ struct wb_writeback_work {
*/
unsigned int dirtytime_expire_interval = 12 * 60 * 60;
-/**
- * writeback_in_progress - determine whether there is writeback in progress
- * @bdi: the device's backing_dev_info structure.
- *
- * Determine whether there is writeback waiting to be handled against a
- * backing device.
- */
-int writeback_in_progress(struct backing_dev_info *bdi)
-{
- return test_bit(BDI_writeback_running, &bdi->state);
-}
-EXPORT_SYMBOL(writeback_in_progress);
-
-struct backing_dev_info *inode_to_bdi(struct inode *inode)
-{
- struct super_block *sb;
-
- if (!inode)
- return &noop_backing_dev_info;
-
- sb = inode->i_sb;
-#ifdef CONFIG_BLOCK
- if (sb_is_blkdev_sb(sb))
- return blk_get_backing_dev_info(I_BDEV(inode));
-#endif
- return sb->s_bdi;
-}
-EXPORT_SYMBOL_GPL(inode_to_bdi);
-
static inline struct inode *wb_inode(struct list_head *head)
{
return list_entry(head, struct inode, i_wb_list);
@@ -109,45 +101,830 @@ static inline struct inode *wb_inode(struct list_head *head)
EXPORT_TRACEPOINT_SYMBOL_GPL(wbc_writepage);
-static void bdi_wakeup_thread(struct backing_dev_info *bdi)
+static bool wb_io_lists_populated(struct bdi_writeback *wb)
+{
+ if (wb_has_dirty_io(wb)) {
+ return false;
+ } else {
+ set_bit(WB_has_dirty_io, &wb->state);
+ WARN_ON_ONCE(!wb->avg_write_bandwidth);
+ atomic_long_add(wb->avg_write_bandwidth,
+ &wb->bdi->tot_write_bandwidth);
+ return true;
+ }
+}
+
+static void wb_io_lists_depopulated(struct bdi_writeback *wb)
{
- spin_lock_bh(&bdi->wb_lock);
- if (test_bit(BDI_registered, &bdi->state))
- mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0);
- spin_unlock_bh(&bdi->wb_lock);
+ if (wb_has_dirty_io(wb) && list_empty(&wb->b_dirty) &&
+ list_empty(&wb->b_io) && list_empty(&wb->b_more_io)) {
+ clear_bit(WB_has_dirty_io, &wb->state);
+ WARN_ON_ONCE(atomic_long_sub_return(wb->avg_write_bandwidth,
+ &wb->bdi->tot_write_bandwidth) < 0);
+ }
}
-static void bdi_queue_work(struct backing_dev_info *bdi,
- struct wb_writeback_work *work)
+/**
+ * inode_wb_list_move_locked - move an inode onto a bdi_writeback IO list
+ * @inode: inode to be moved
+ * @wb: target bdi_writeback
+ * @head: one of @wb->b_{dirty|io|more_io}
+ *
+ * Move @inode->i_wb_list to @list of @wb and set %WB_has_dirty_io.
+ * Returns %true if @inode is the first occupant of the !dirty_time IO
+ * lists; otherwise, %false.
+ */
+static bool inode_wb_list_move_locked(struct inode *inode,
+ struct bdi_writeback *wb,
+ struct list_head *head)
{
- trace_writeback_queue(bdi, work);
+ assert_spin_locked(&wb->list_lock);
+
+ list_move(&inode->i_wb_list, head);
- spin_lock_bh(&bdi->wb_lock);
- if (!test_bit(BDI_registered, &bdi->state)) {
- if (work->done)
- complete(work->done);
+ /* dirty_time doesn't count as dirty_io until expiration */
+ if (head != &wb->b_dirty_time)
+ return wb_io_lists_populated(wb);
+
+ wb_io_lists_depopulated(wb);
+ return false;
+}
+
+/**
+ * inode_wb_list_del_locked - remove an inode from its bdi_writeback IO list
+ * @inode: inode to be removed
+ * @wb: bdi_writeback @inode is being removed from
+ *
+ * Remove @inode which may be on one of @wb->b_{dirty|io|more_io} lists and
+ * clear %WB_has_dirty_io if all are empty afterwards.
+ */
+static void inode_wb_list_del_locked(struct inode *inode,
+ struct bdi_writeback *wb)
+{
+ assert_spin_locked(&wb->list_lock);
+
+ list_del_init(&inode->i_wb_list);
+ wb_io_lists_depopulated(wb);
+}
+
+static void wb_wakeup(struct bdi_writeback *wb)
+{
+ spin_lock_bh(&wb->work_lock);
+ if (test_bit(WB_registered, &wb->state))
+ mod_delayed_work(bdi_wq, &wb->dwork, 0);
+ spin_unlock_bh(&wb->work_lock);
+}
+
+static void wb_queue_work(struct bdi_writeback *wb,
+ struct wb_writeback_work *work)
+{
+ trace_writeback_queue(wb->bdi, work);
+
+ spin_lock_bh(&wb->work_lock);
+ if (!test_bit(WB_registered, &wb->state)) {
+ if (work->single_wait)
+ work->single_done = 1;
goto out_unlock;
}
- list_add_tail(&work->list, &bdi->work_list);
- mod_delayed_work(bdi_wq, &bdi->wb.dwork, 0);
+ if (work->done)
+ atomic_inc(&work->done->cnt);
+ list_add_tail(&work->list, &wb->work_list);
+ mod_delayed_work(bdi_wq, &wb->dwork, 0);
out_unlock:
- spin_unlock_bh(&bdi->wb_lock);
+ spin_unlock_bh(&wb->work_lock);
+}
+
+/**
+ * wb_wait_for_completion - wait for completion of bdi_writeback_works
+ * @bdi: bdi work items were issued to
+ * @done: target wb_completion
+ *
+ * Wait for one or more work items issued to @bdi with their ->done field
+ * set to @done, which should have been defined with
+ * DEFINE_WB_COMPLETION_ONSTACK(). This function returns after all such
+ * work items are completed. Work items which are waited upon aren't freed
+ * automatically on completion.
+ */
+static void wb_wait_for_completion(struct backing_dev_info *bdi,
+ struct wb_completion *done)
+{
+ atomic_dec(&done->cnt); /* put down the initial count */
+ wait_event(bdi->wb_waitq, !atomic_read(&done->cnt));
+}
+
+#ifdef CONFIG_CGROUP_WRITEBACK
+
+/* parameters for foreign inode detection, see wb_detach_inode() */
+#define WB_FRN_TIME_SHIFT 13 /* 1s = 2^13, upto 8 secs w/ 16bit */
+#define WB_FRN_TIME_AVG_SHIFT 3 /* avg = avg * 7/8 + new * 1/8 */
+#define WB_FRN_TIME_CUT_DIV 2 /* ignore rounds < avg / 2 */
+#define WB_FRN_TIME_PERIOD (2 * (1 << WB_FRN_TIME_SHIFT)) /* 2s */
+
+#define WB_FRN_HIST_SLOTS 16 /* inode->i_wb_frn_history is 16bit */
+#define WB_FRN_HIST_UNIT (WB_FRN_TIME_PERIOD / WB_FRN_HIST_SLOTS)
+ /* each slot's duration is 2s / 16 */
+#define WB_FRN_HIST_THR_SLOTS (WB_FRN_HIST_SLOTS / 2)
+ /* if foreign slots >= 8, switch */
+#define WB_FRN_HIST_MAX_SLOTS (WB_FRN_HIST_THR_SLOTS / 2 + 1)
+ /* one round can affect upto 5 slots */
+
+void __inode_attach_wb(struct inode *inode, struct page *page)
+{
+ struct backing_dev_info *bdi = inode_to_bdi(inode);
+ struct bdi_writeback *wb = NULL;
+
+ if (inode_cgwb_enabled(inode)) {
+ struct cgroup_subsys_state *memcg_css;
+
+ if (page) {
+ memcg_css = mem_cgroup_css_from_page(page);
+ wb = wb_get_create(bdi, memcg_css, GFP_ATOMIC);
+ } else {
+ /* must pin memcg_css, see wb_get_create() */
+ memcg_css = task_get_css(current, memory_cgrp_id);
+ wb = wb_get_create(bdi, memcg_css, GFP_ATOMIC);
+ css_put(memcg_css);
+ }
+ }
+
+ if (!wb)
+ wb = &bdi->wb;
+
+ /*
+ * There may be multiple instances of this function racing to
+ * update the same inode. Use cmpxchg() to tell the winner.
+ */
+ if (unlikely(cmpxchg(&inode->i_wb, NULL, wb)))
+ wb_put(wb);
+}
+
+/**
+ * locked_inode_to_wb_and_lock_list - determine a locked inode's wb and lock it
+ * @inode: inode of interest with i_lock held
+ *
+ * Returns @inode's wb with its list_lock held. @inode->i_lock must be
+ * held on entry and is released on return. The returned wb is guaranteed
+ * to stay @inode's associated wb until its list_lock is released.
+ */
+static struct bdi_writeback *
+locked_inode_to_wb_and_lock_list(struct inode *inode)
+ __releases(&inode->i_lock)
+ __acquires(&wb->list_lock)
+{
+ while (true) {
+ struct bdi_writeback *wb = inode_to_wb(inode);
+
+ /*
+ * inode_to_wb() association is protected by both
+ * @inode->i_lock and @wb->list_lock but list_lock nests
+ * outside i_lock. Drop i_lock and verify that the
+ * association hasn't changed after acquiring list_lock.
+ */
+ wb_get(wb);
+ spin_unlock(&inode->i_lock);
+ spin_lock(&wb->list_lock);
+ wb_put(wb); /* not gonna deref it anymore */
+
+ /* i_wb may have changed inbetween, can't use inode_to_wb() */
+ if (likely(wb == inode->i_wb))
+ return wb; /* @inode already has ref */
+
+ spin_unlock(&wb->list_lock);
+ cpu_relax();
+ spin_lock(&inode->i_lock);
+ }
+}
+
+/**
+ * inode_to_wb_and_lock_list - determine an inode's wb and lock it
+ * @inode: inode of interest
+ *
+ * Same as locked_inode_to_wb_and_lock_list() but @inode->i_lock isn't held
+ * on entry.
+ */
+static struct bdi_writeback *inode_to_wb_and_lock_list(struct inode *inode)
+ __acquires(&wb->list_lock)
+{
+ spin_lock(&inode->i_lock);
+ return locked_inode_to_wb_and_lock_list(inode);
+}
+
+struct inode_switch_wbs_context {
+ struct inode *inode;
+ struct bdi_writeback *new_wb;
+
+ struct rcu_head rcu_head;
+ struct work_struct work;
+};
+
+static void inode_switch_wbs_work_fn(struct work_struct *work)
+{
+ struct inode_switch_wbs_context *isw =
+ container_of(work, struct inode_switch_wbs_context, work);
+ struct inode *inode = isw->inode;
+ struct address_space *mapping = inode->i_mapping;
+ struct bdi_writeback *old_wb = inode->i_wb;
+ struct bdi_writeback *new_wb = isw->new_wb;
+ struct radix_tree_iter iter;
+ bool switched = false;
+ void **slot;
+
+ /*
+ * By the time control reaches here, RCU grace period has passed
+ * since I_WB_SWITCH assertion and all wb stat update transactions
+ * between unlocked_inode_to_wb_begin/end() are guaranteed to be
+ * synchronizing against mapping->tree_lock.
+ *
+ * Grabbing old_wb->list_lock, inode->i_lock and mapping->tree_lock
+ * gives us exclusion against all wb related operations on @inode
+ * including IO list manipulations and stat updates.
+ */
+ if (old_wb < new_wb) {
+ spin_lock(&old_wb->list_lock);
+ spin_lock_nested(&new_wb->list_lock, SINGLE_DEPTH_NESTING);
+ } else {
+ spin_lock(&new_wb->list_lock);
+ spin_lock_nested(&old_wb->list_lock, SINGLE_DEPTH_NESTING);
+ }
+ spin_lock(&inode->i_lock);
+ spin_lock_irq(&mapping->tree_lock);
+
+ /*
+ * Once I_FREEING is visible under i_lock, the eviction path owns
+ * the inode and we shouldn't modify ->i_wb_list.
+ */
+ if (unlikely(inode->i_state & I_FREEING))
+ goto skip_switch;
+
+ /*
+ * Count and transfer stats. Note that PAGECACHE_TAG_DIRTY points
+ * to possibly dirty pages while PAGECACHE_TAG_WRITEBACK points to
+ * pages actually under underwriteback.
+ */
+ radix_tree_for_each_tagged(slot, &mapping->page_tree, &iter, 0,
+ PAGECACHE_TAG_DIRTY) {
+ struct page *page = radix_tree_deref_slot_protected(slot,
+ &mapping->tree_lock);
+ if (likely(page) && PageDirty(page)) {
+ __dec_wb_stat(old_wb, WB_RECLAIMABLE);
+ __inc_wb_stat(new_wb, WB_RECLAIMABLE);
+ }
+ }
+
+ radix_tree_for_each_tagged(slot, &mapping->page_tree, &iter, 0,
+ PAGECACHE_TAG_WRITEBACK) {
+ struct page *page = radix_tree_deref_slot_protected(slot,
+ &mapping->tree_lock);
+ if (likely(page)) {
+ WARN_ON_ONCE(!PageWriteback(page));
+ __dec_wb_stat(old_wb, WB_WRITEBACK);
+ __inc_wb_stat(new_wb, WB_WRITEBACK);
+ }
+ }
+
+ wb_get(new_wb);
+
+ /*
+ * Transfer to @new_wb's IO list if necessary. The specific list
+ * @inode was on is ignored and the inode is put on ->b_dirty which
+ * is always correct including from ->b_dirty_time. The transfer
+ * preserves @inode->dirtied_when ordering.
+ */
+ if (!list_empty(&inode->i_wb_list)) {
+ struct inode *pos;
+
+ inode_wb_list_del_locked(inode, old_wb);
+ inode->i_wb = new_wb;
+ list_for_each_entry(pos, &new_wb->b_dirty, i_wb_list)
+ if (time_after_eq(inode->dirtied_when,
+ pos->dirtied_when))
+ break;
+ inode_wb_list_move_locked(inode, new_wb, pos->i_wb_list.prev);
+ } else {
+ inode->i_wb = new_wb;
+ }
+
+ /* ->i_wb_frn updates may race wbc_detach_inode() but doesn't matter */
+ inode->i_wb_frn_winner = 0;
+ inode->i_wb_frn_avg_time = 0;
+ inode->i_wb_frn_history = 0;
+ switched = true;
+skip_switch:
+ /*
+ * Paired with load_acquire in unlocked_inode_to_wb_begin() and
+ * ensures that the new wb is visible if they see !I_WB_SWITCH.
+ */
+ smp_store_release(&inode->i_state, inode->i_state & ~I_WB_SWITCH);
+
+ spin_unlock_irq(&mapping->tree_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&new_wb->list_lock);
+ spin_unlock(&old_wb->list_lock);
+
+ if (switched) {
+ wb_wakeup(new_wb);
+ wb_put(old_wb);
+ }
+ wb_put(new_wb);
+
+ iput(inode);
+ kfree(isw);
+}
+
+static void inode_switch_wbs_rcu_fn(struct rcu_head *rcu_head)
+{
+ struct inode_switch_wbs_context *isw = container_of(rcu_head,
+ struct inode_switch_wbs_context, rcu_head);
+
+ /* needs to grab bh-unsafe locks, bounce to work item */
+ INIT_WORK(&isw->work, inode_switch_wbs_work_fn);
+ schedule_work(&isw->work);
+}
+
+/**
+ * inode_switch_wbs - change the wb association of an inode
+ * @inode: target inode
+ * @new_wb_id: ID of the new wb
+ *
+ * Switch @inode's wb association to the wb identified by @new_wb_id. The
+ * switching is performed asynchronously and may fail silently.
+ */
+static void inode_switch_wbs(struct inode *inode, int new_wb_id)
+{
+ struct backing_dev_info *bdi = inode_to_bdi(inode);
+ struct cgroup_subsys_state *memcg_css;
+ struct inode_switch_wbs_context *isw;
+
+ /* noop if seems to be already in progress */
+ if (inode->i_state & I_WB_SWITCH)
+ return;
+
+ isw = kzalloc(sizeof(*isw), GFP_ATOMIC);
+ if (!isw)
+ return;
+
+ /* find and pin the new wb */
+ rcu_read_lock();
+ memcg_css = css_from_id(new_wb_id, &memory_cgrp_subsys);
+ if (memcg_css)
+ isw->new_wb = wb_get_create(bdi, memcg_css, GFP_ATOMIC);
+ rcu_read_unlock();
+ if (!isw->new_wb)
+ goto out_free;
+
+ /* while holding I_WB_SWITCH, no one else can update the association */
+ spin_lock(&inode->i_lock);
+ if (inode->i_state & (I_WB_SWITCH | I_FREEING) ||
+ inode_to_wb(inode) == isw->new_wb) {
+ spin_unlock(&inode->i_lock);
+ goto out_free;
+ }
+ inode->i_state |= I_WB_SWITCH;
+ spin_unlock(&inode->i_lock);
+
+ ihold(inode);
+ isw->inode = inode;
+
+ /*
+ * In addition to synchronizing among switchers, I_WB_SWITCH tells
+ * the RCU protected stat update paths to grab the mapping's
+ * tree_lock so that stat transfer can synchronize against them.
+ * Let's continue after I_WB_SWITCH is guaranteed to be visible.
+ */
+ call_rcu(&isw->rcu_head, inode_switch_wbs_rcu_fn);
+ return;
+
+out_free:
+ if (isw->new_wb)
+ wb_put(isw->new_wb);
+ kfree(isw);
+}
+
+/**
+ * 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)
+{
+ if (!inode_cgwb_enabled(inode)) {
+ spin_unlock(&inode->i_lock);
+ return;
+ }
+
+ wbc->wb = inode_to_wb(inode);
+ wbc->inode = inode;
+
+ wbc->wb_id = wbc->wb->memcg_css->id;
+ wbc->wb_lcand_id = inode->i_wb_frn_winner;
+ wbc->wb_tcand_id = 0;
+ wbc->wb_bytes = 0;
+ wbc->wb_lcand_bytes = 0;
+ wbc->wb_tcand_bytes = 0;
+
+ wb_get(wbc->wb);
+ spin_unlock(&inode->i_lock);
+
+ /*
+ * A dying wb indicates that the memcg-blkcg mapping has changed
+ * and a new wb is already serving the memcg. Switch immediately.
+ */
+ if (unlikely(wb_dying(wbc->wb)))
+ inode_switch_wbs(inode, wbc->wb_id);
+}
+
+/**
+ * wbc_detach_inode - disassociate wbc from inode and perform foreign detection
+ * @wbc: writeback_control of the just finished writeback
+ *
+ * To be called after a writeback attempt of an inode finishes and undoes
+ * wbc_attach_and_unlock_inode(). Can be called under any context.
+ *
+ * As concurrent write sharing of an inode is expected to be very rare and
+ * memcg only tracks page ownership on first-use basis severely confining
+ * the usefulness of such sharing, cgroup writeback tracks ownership
+ * per-inode. While the support for concurrent write sharing of an inode
+ * is deemed unnecessary, an inode being written to by different cgroups at
+ * different points in time is a lot more common, and, more importantly,
+ * charging only by first-use can too readily lead to grossly incorrect
+ * behaviors (single foreign page can lead to gigabytes of writeback to be
+ * incorrectly attributed).
+ *
+ * To resolve this issue, cgroup writeback detects the majority dirtier of
+ * an inode and transfers the ownership to it. To avoid unnnecessary
+ * oscillation, the detection mechanism keeps track of history and gives
+ * out the switch verdict only if the foreign usage pattern is stable over
+ * a certain amount of time and/or writeback attempts.
+ *
+ * On each writeback attempt, @wbc tries to detect the majority writer
+ * using Boyer-Moore majority vote algorithm. In addition to the byte
+ * count from the majority voting, it also counts the bytes written for the
+ * current wb and the last round's winner wb (max of last round's current
+ * wb, the winner from two rounds ago, and the last round's majority
+ * candidate). Keeping track of the historical winner helps the algorithm
+ * to semi-reliably detect the most active writer even when it's not the
+ * absolute majority.
+ *
+ * Once the winner of the round is determined, whether the winner is
+ * foreign or not and how much IO time the round consumed is recorded in
+ * inode->i_wb_frn_history. If the amount of recorded foreign IO time is
+ * over a certain threshold, the switch verdict is given.
+ */
+void wbc_detach_inode(struct writeback_control *wbc)
+{
+ struct bdi_writeback *wb = wbc->wb;
+ struct inode *inode = wbc->inode;
+ unsigned long avg_time, max_bytes, max_time;
+ u16 history;
+ int max_id;
+
+ if (!wb)
+ return;
+
+ history = inode->i_wb_frn_history;
+ avg_time = inode->i_wb_frn_avg_time;
+
+ /* pick the winner of this round */
+ if (wbc->wb_bytes >= wbc->wb_lcand_bytes &&
+ wbc->wb_bytes >= wbc->wb_tcand_bytes) {
+ max_id = wbc->wb_id;
+ max_bytes = wbc->wb_bytes;
+ } else if (wbc->wb_lcand_bytes >= wbc->wb_tcand_bytes) {
+ max_id = wbc->wb_lcand_id;
+ max_bytes = wbc->wb_lcand_bytes;
+ } else {
+ max_id = wbc->wb_tcand_id;
+ max_bytes = wbc->wb_tcand_bytes;
+ }
+
+ /*
+ * Calculate the amount of IO time the winner consumed and fold it
+ * into the running average kept per inode. If the consumed IO
+ * time is lower than avag / WB_FRN_TIME_CUT_DIV, ignore it for
+ * deciding whether to switch or not. This is to prevent one-off
+ * small dirtiers from skewing the verdict.
+ */
+ max_time = DIV_ROUND_UP((max_bytes >> PAGE_SHIFT) << WB_FRN_TIME_SHIFT,
+ wb->avg_write_bandwidth);
+ if (avg_time)
+ avg_time += (max_time >> WB_FRN_TIME_AVG_SHIFT) -
+ (avg_time >> WB_FRN_TIME_AVG_SHIFT);
+ else
+ avg_time = max_time; /* immediate catch up on first run */
+
+ if (max_time >= avg_time / WB_FRN_TIME_CUT_DIV) {
+ int slots;
+
+ /*
+ * The switch verdict is reached if foreign wb's consume
+ * more than a certain proportion of IO time in a
+ * WB_FRN_TIME_PERIOD. This is loosely tracked by 16 slot
+ * history mask where each bit represents one sixteenth of
+ * the period. Determine the number of slots to shift into
+ * history from @max_time.
+ */
+ slots = min(DIV_ROUND_UP(max_time, WB_FRN_HIST_UNIT),
+ (unsigned long)WB_FRN_HIST_MAX_SLOTS);
+ history <<= slots;
+ if (wbc->wb_id != max_id)
+ history |= (1U << slots) - 1;
+
+ /*
+ * Switch if the current wb isn't the consistent winner.
+ * If there are multiple closely competing dirtiers, the
+ * inode may switch across them repeatedly over time, which
+ * is okay. The main goal is avoiding keeping an inode on
+ * the wrong wb for an extended period of time.
+ */
+ if (hweight32(history) > WB_FRN_HIST_THR_SLOTS)
+ inode_switch_wbs(inode, max_id);
+ }
+
+ /*
+ * Multiple instances of this function may race to update the
+ * following fields but we don't mind occassional inaccuracies.
+ */
+ inode->i_wb_frn_winner = max_id;
+ inode->i_wb_frn_avg_time = min(avg_time, (unsigned long)U16_MAX);
+ inode->i_wb_frn_history = history;
+
+ wb_put(wbc->wb);
+ wbc->wb = NULL;
+}
+
+/**
+ * wbc_account_io - account IO issued during writeback
+ * @wbc: writeback_control of the writeback in progress
+ * @page: page being written out
+ * @bytes: number of bytes being written out
+ *
+ * @bytes from @page are about to written out during the writeback
+ * controlled by @wbc. Keep the book for foreign inode detection. See
+ * wbc_detach_inode().
+ */
+void wbc_account_io(struct writeback_control *wbc, struct page *page,
+ size_t bytes)
+{
+ int id;
+
+ /*
+ * 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)
+ return;
+
+ rcu_read_lock();
+ id = mem_cgroup_css_from_page(page)->id;
+ rcu_read_unlock();
+
+ if (id == wbc->wb_id) {
+ wbc->wb_bytes += bytes;
+ return;
+ }
+
+ if (id == wbc->wb_lcand_id)
+ wbc->wb_lcand_bytes += bytes;
+
+ /* Boyer-Moore majority vote algorithm */
+ if (!wbc->wb_tcand_bytes)
+ wbc->wb_tcand_id = id;
+ if (id == wbc->wb_tcand_id)
+ wbc->wb_tcand_bytes += bytes;
+ else
+ wbc->wb_tcand_bytes -= min(bytes, wbc->wb_tcand_bytes);
}
-static void
-__bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
- bool range_cyclic, enum wb_reason reason)
+/**
+ * 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
+ *
+ * Tests whether @inode is congested. @cong_bits is the mask of congestion
+ * bits to test and the return value is the mask of set bits.
+ *
+ * If cgroup writeback is enabled for @inode, the congestion state is
+ * determined by whether the cgwb (cgroup bdi_writeback) for the blkcg
+ * associated with @inode is congested; otherwise, the root wb's congestion
+ * state is used.
+ */
+int inode_congested(struct inode *inode, int cong_bits)
+{
+ /*
+ * Once set, ->i_wb never becomes NULL while the inode is alive.
+ * Start transaction iff ->i_wb is visible.
+ */
+ if (inode && inode_to_wb_is_valid(inode)) {
+ struct bdi_writeback *wb;
+ bool locked, congested;
+
+ wb = unlocked_inode_to_wb_begin(inode, &locked);
+ congested = wb_congested(wb, cong_bits);
+ unlocked_inode_to_wb_end(inode, locked);
+ return congested;
+ }
+
+ return wb_congested(&inode_to_bdi(inode)->wb, cong_bits);
+}
+EXPORT_SYMBOL_GPL(inode_congested);
+
+/**
+ * wb_wait_for_single_work - wait for completion of a single bdi_writeback_work
+ * @bdi: bdi the work item was issued to
+ * @work: work item to wait for
+ *
+ * Wait for the completion of @work which was issued to one of @bdi's
+ * bdi_writeback's. The caller must have set @work->single_wait before
+ * issuing it. This wait operates independently fo
+ * wb_wait_for_completion() and also disables automatic freeing of @work.
+ */
+static void wb_wait_for_single_work(struct backing_dev_info *bdi,
+ struct wb_writeback_work *work)
+{
+ if (WARN_ON_ONCE(!work->single_wait))
+ return;
+
+ wait_event(bdi->wb_waitq, work->single_done);
+
+ /*
+ * Paired with smp_wmb() in wb_do_writeback() and ensures that all
+ * modifications to @work prior to assertion of ->single_done is
+ * visible to the caller once this function returns.
+ */
+ smp_rmb();
+}
+
+/**
+ * wb_split_bdi_pages - split nr_pages to write according to bandwidth
+ * @wb: target bdi_writeback to split @nr_pages to
+ * @nr_pages: number of pages to write for the whole bdi
+ *
+ * Split @wb's portion of @nr_pages according to @wb's write bandwidth in
+ * relation to the total write bandwidth of all wb's w/ dirty inodes on
+ * @wb->bdi.
+ */
+static long wb_split_bdi_pages(struct bdi_writeback *wb, long nr_pages)
+{
+ unsigned long this_bw = wb->avg_write_bandwidth;
+ unsigned long tot_bw = atomic_long_read(&wb->bdi->tot_write_bandwidth);
+
+ if (nr_pages == LONG_MAX)
+ return LONG_MAX;
+
+ /*
+ * This may be called on clean wb's and proportional distribution
+ * may not make sense, just use the original @nr_pages in those
+ * cases. In general, we wanna err on the side of writing more.
+ */
+ if (!tot_bw || this_bw >= tot_bw)
+ return nr_pages;
+ else
+ return DIV_ROUND_UP_ULL((u64)nr_pages * this_bw, tot_bw);
+}
+
+/**
+ * wb_clone_and_queue_work - clone a wb_writeback_work and issue it to a wb
+ * @wb: target bdi_writeback
+ * @base_work: source wb_writeback_work
+ *
+ * Try to make a clone of @base_work and issue it to @wb. If cloning
+ * succeeds, %true is returned; otherwise, @base_work is issued directly
+ * and %false is returned. In the latter case, the caller is required to
+ * wait for @base_work's completion using wb_wait_for_single_work().
+ *
+ * A clone is auto-freed on completion. @base_work never is.
+ */
+static bool wb_clone_and_queue_work(struct bdi_writeback *wb,
+ struct wb_writeback_work *base_work)
{
struct wb_writeback_work *work;
+ work = kmalloc(sizeof(*work), GFP_ATOMIC);
+ if (work) {
+ *work = *base_work;
+ work->auto_free = 1;
+ work->single_wait = 0;
+ } else {
+ work = base_work;
+ work->auto_free = 0;
+ work->single_wait = 1;
+ }
+ work->single_done = 0;
+ wb_queue_work(wb, work);
+ return work != base_work;
+}
+
+/**
+ * bdi_split_work_to_wbs - split a wb_writeback_work to all wb's of a bdi
+ * @bdi: target backing_dev_info
+ * @base_work: wb_writeback_work to issue
+ * @skip_if_busy: skip wb's which already have writeback in progress
+ *
+ * Split and issue @base_work to all wb's (bdi_writeback's) of @bdi which
+ * have dirty inodes. If @base_work->nr_page isn't %LONG_MAX, it's
+ * distributed to the busy wbs according to each wb's proportion in the
+ * total active write bandwidth of @bdi.
+ */
+static void bdi_split_work_to_wbs(struct backing_dev_info *bdi,
+ struct wb_writeback_work *base_work,
+ bool skip_if_busy)
+{
+ long nr_pages = base_work->nr_pages;
+ int next_blkcg_id = 0;
+ struct bdi_writeback *wb;
+ struct wb_iter iter;
+
+ might_sleep();
+
+ if (!bdi_has_dirty_io(bdi))
+ return;
+restart:
+ rcu_read_lock();
+ bdi_for_each_wb(wb, bdi, &iter, next_blkcg_id) {
+ if (!wb_has_dirty_io(wb) ||
+ (skip_if_busy && writeback_in_progress(wb)))
+ continue;
+
+ base_work->nr_pages = wb_split_bdi_pages(wb, nr_pages);
+ if (!wb_clone_and_queue_work(wb, base_work)) {
+ next_blkcg_id = wb->blkcg_css->id + 1;
+ rcu_read_unlock();
+ wb_wait_for_single_work(bdi, base_work);
+ goto restart;
+ }
+ }
+ rcu_read_unlock();
+}
+
+#else /* CONFIG_CGROUP_WRITEBACK */
+
+static struct bdi_writeback *
+locked_inode_to_wb_and_lock_list(struct inode *inode)
+ __releases(&inode->i_lock)
+ __acquires(&wb->list_lock)
+{
+ struct bdi_writeback *wb = inode_to_wb(inode);
+
+ spin_unlock(&inode->i_lock);
+ spin_lock(&wb->list_lock);
+ return wb;
+}
+
+static struct bdi_writeback *inode_to_wb_and_lock_list(struct inode *inode)
+ __acquires(&wb->list_lock)
+{
+ struct bdi_writeback *wb = inode_to_wb(inode);
+
+ spin_lock(&wb->list_lock);
+ return wb;
+}
+
+static long wb_split_bdi_pages(struct bdi_writeback *wb, long nr_pages)
+{
+ return nr_pages;
+}
+
+static void bdi_split_work_to_wbs(struct backing_dev_info *bdi,
+ struct wb_writeback_work *base_work,
+ bool skip_if_busy)
+{
+ might_sleep();
+
+ if (bdi_has_dirty_io(bdi) &&
+ (!skip_if_busy || !writeback_in_progress(&bdi->wb))) {
+ base_work->auto_free = 0;
+ base_work->single_wait = 0;
+ base_work->single_done = 0;
+ wb_queue_work(&bdi->wb, base_work);
+ }
+}
+
+#endif /* CONFIG_CGROUP_WRITEBACK */
+
+void wb_start_writeback(struct bdi_writeback *wb, long nr_pages,
+ bool range_cyclic, enum wb_reason reason)
+{
+ struct wb_writeback_work *work;
+
+ if (!wb_has_dirty_io(wb))
+ return;
+
/*
* This is WB_SYNC_NONE writeback, so if allocation fails just
* wakeup the thread for old dirty data writeback
*/
work = kzalloc(sizeof(*work), GFP_ATOMIC);
if (!work) {
- trace_writeback_nowork(bdi);
- bdi_wakeup_thread(bdi);
+ trace_writeback_nowork(wb->bdi);
+ wb_wakeup(wb);
return;
}
@@ -155,46 +932,29 @@ __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
work->nr_pages = nr_pages;
work->range_cyclic = range_cyclic;
work->reason = reason;
+ work->auto_free = 1;
- bdi_queue_work(bdi, work);
+ wb_queue_work(wb, work);
}
/**
- * bdi_start_writeback - start writeback
- * @bdi: the backing device to write from
- * @nr_pages: the number of pages to write
- * @reason: reason why some writeback work was initiated
- *
- * Description:
- * This does WB_SYNC_NONE opportunistic writeback. The IO is only
- * started when this function returns, we make no guarantees on
- * completion. Caller need not hold sb s_umount semaphore.
- *
- */
-void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
- enum wb_reason reason)
-{
- __bdi_start_writeback(bdi, nr_pages, true, reason);
-}
-
-/**
- * bdi_start_background_writeback - start background writeback
- * @bdi: the backing device to write from
+ * wb_start_background_writeback - start background writeback
+ * @wb: bdi_writback to write from
*
* Description:
* This makes sure WB_SYNC_NONE background writeback happens. When
- * this function returns, it is only guaranteed that for given BDI
+ * this function returns, it is only guaranteed that for given wb
* some IO is happening if we are over background dirty threshold.
* Caller need not hold sb s_umount semaphore.
*/
-void bdi_start_background_writeback(struct backing_dev_info *bdi)
+void wb_start_background_writeback(struct bdi_writeback *wb)
{
/*
* We just wake up the flusher thread. It will perform background
* writeback as soon as there is no other work to do.
*/
- trace_writeback_wake_background(bdi);
- bdi_wakeup_thread(bdi);
+ trace_writeback_wake_background(wb->bdi);
+ wb_wakeup(wb);
}
/*
@@ -202,11 +962,11 @@ void bdi_start_background_writeback(struct backing_dev_info *bdi)
*/
void inode_wb_list_del(struct inode *inode)
{
- struct backing_dev_info *bdi = inode_to_bdi(inode);
+ struct bdi_writeback *wb;
- spin_lock(&bdi->wb.list_lock);
- list_del_init(&inode->i_wb_list);
- spin_unlock(&bdi->wb.list_lock);
+ wb = inode_to_wb_and_lock_list(inode);
+ inode_wb_list_del_locked(inode, wb);
+ spin_unlock(&wb->list_lock);
}
/*
@@ -220,7 +980,6 @@ void inode_wb_list_del(struct inode *inode)
*/
static void redirty_tail(struct inode *inode, struct bdi_writeback *wb)
{
- assert_spin_locked(&wb->list_lock);
if (!list_empty(&wb->b_dirty)) {
struct inode *tail;
@@ -228,7 +987,7 @@ static void redirty_tail(struct inode *inode, struct bdi_writeback *wb)
if (time_before(inode->dirtied_when, tail->dirtied_when))
inode->dirtied_when = jiffies;
}
- list_move(&inode->i_wb_list, &wb->b_dirty);
+ inode_wb_list_move_locked(inode, wb, &wb->b_dirty);
}
/*
@@ -236,8 +995,7 @@ static void redirty_tail(struct inode *inode, struct bdi_writeback *wb)
*/
static void requeue_io(struct inode *inode, struct bdi_writeback *wb)
{
- assert_spin_locked(&wb->list_lock);
- list_move(&inode->i_wb_list, &wb->b_more_io);
+ inode_wb_list_move_locked(inode, wb, &wb->b_more_io);
}
static void inode_sync_complete(struct inode *inode)
@@ -346,6 +1104,8 @@ static void queue_io(struct bdi_writeback *wb, struct wb_writeback_work *work)
moved = move_expired_inodes(&wb->b_dirty, &wb->b_io, 0, work);
moved += move_expired_inodes(&wb->b_dirty_time, &wb->b_io,
EXPIRE_DIRTY_ATIME, work);
+ if (moved)
+ wb_io_lists_populated(wb);
trace_writeback_queue_io(wb, work, moved);
}
@@ -471,10 +1231,10 @@ static void requeue_inode(struct inode *inode, struct bdi_writeback *wb,
redirty_tail(inode, wb);
} else if (inode->i_state & I_DIRTY_TIME) {
inode->dirtied_when = jiffies;
- list_move(&inode->i_wb_list, &wb->b_dirty_time);
+ inode_wb_list_move_locked(inode, wb, &wb->b_dirty_time);
} else {
/* The inode is clean. Remove from writeback lists. */
- list_del_init(&inode->i_wb_list);
+ inode_wb_list_del_locked(inode, wb);
}
}
@@ -605,10 +1365,11 @@ 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);
/*
@@ -616,7 +1377,7 @@ writeback_single_inode(struct inode *inode, struct bdi_writeback *wb,
* touch it. See comment above for explanation.
*/
if (!(inode->i_state & I_DIRTY_ALL))
- list_del_init(&inode->i_wb_list);
+ inode_wb_list_del_locked(inode, wb);
spin_unlock(&wb->list_lock);
inode_sync_complete(inode);
out:
@@ -624,7 +1385,7 @@ out:
return ret;
}
-static long writeback_chunk_size(struct backing_dev_info *bdi,
+static long writeback_chunk_size(struct bdi_writeback *wb,
struct wb_writeback_work *work)
{
long pages;
@@ -645,8 +1406,8 @@ static long writeback_chunk_size(struct backing_dev_info *bdi,
if (work->sync_mode == WB_SYNC_ALL || work->tagged_writepages)
pages = LONG_MAX;
else {
- pages = min(bdi->avg_write_bandwidth / 2,
- global_dirty_limit / DIRTY_SCOPE);
+ pages = min(wb->avg_write_bandwidth / 2,
+ global_wb_domain.dirty_limit / DIRTY_SCOPE);
pages = min(pages, work->nr_pages);
pages = round_down(pages + MIN_WRITEBACK_PAGES,
MIN_WRITEBACK_PAGES);
@@ -741,9 +1502,9 @@ 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->bdi, work);
+ write_chunk = writeback_chunk_size(wb, work);
wbc.nr_to_write = write_chunk;
wbc.pages_skipped = 0;
@@ -753,6 +1514,7 @@ 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);
@@ -830,33 +1592,6 @@ static long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages,
return nr_pages - work.nr_pages;
}
-static bool over_bground_thresh(struct backing_dev_info *bdi)
-{
- unsigned long background_thresh, dirty_thresh;
-
- global_dirty_limits(&background_thresh, &dirty_thresh);
-
- if (global_page_state(NR_FILE_DIRTY) +
- global_page_state(NR_UNSTABLE_NFS) > background_thresh)
- return true;
-
- if (bdi_stat(bdi, BDI_RECLAIMABLE) >
- bdi_dirty_limit(bdi, background_thresh))
- return true;
-
- return false;
-}
-
-/*
- * Called under wb->list_lock. If there are multiple wb per bdi,
- * only the flusher working on the first wb should do it.
- */
-static void wb_update_bandwidth(struct bdi_writeback *wb,
- unsigned long start_time)
-{
- __bdi_update_bandwidth(wb->bdi, 0, 0, 0, 0, 0, start_time);
-}
-
/*
* Explicit flushing or periodic writeback of "old" data.
*
@@ -899,14 +1634,14 @@ static long wb_writeback(struct bdi_writeback *wb,
* after the other works are all done.
*/
if ((work->for_background || work->for_kupdate) &&
- !list_empty(&wb->bdi->work_list))
+ !list_empty(&wb->work_list))
break;
/*
* For background writeout, stop when we are below the
* background dirty threshold
*/
- if (work->for_background && !over_bground_thresh(wb->bdi))
+ if (work->for_background && !wb_over_bg_thresh(wb))
break;
/*
@@ -970,18 +1705,17 @@ static long wb_writeback(struct bdi_writeback *wb,
/*
* Return the next wb_writeback_work struct that hasn't been processed yet.
*/
-static struct wb_writeback_work *
-get_next_work_item(struct backing_dev_info *bdi)
+static struct wb_writeback_work *get_next_work_item(struct bdi_writeback *wb)
{
struct wb_writeback_work *work = NULL;
- spin_lock_bh(&bdi->wb_lock);
- if (!list_empty(&bdi->work_list)) {
- work = list_entry(bdi->work_list.next,
+ spin_lock_bh(&wb->work_lock);
+ if (!list_empty(&wb->work_list)) {
+ work = list_entry(wb->work_list.next,
struct wb_writeback_work, list);
list_del_init(&work->list);
}
- spin_unlock_bh(&bdi->wb_lock);
+ spin_unlock_bh(&wb->work_lock);
return work;
}
@@ -998,7 +1732,7 @@ static unsigned long get_nr_dirty_pages(void)
static long wb_check_background_flush(struct bdi_writeback *wb)
{
- if (over_bground_thresh(wb->bdi)) {
+ if (wb_over_bg_thresh(wb)) {
struct wb_writeback_work work = {
.nr_pages = LONG_MAX,
@@ -1053,25 +1787,33 @@ static long wb_check_old_data_flush(struct bdi_writeback *wb)
*/
static long wb_do_writeback(struct bdi_writeback *wb)
{
- struct backing_dev_info *bdi = wb->bdi;
struct wb_writeback_work *work;
long wrote = 0;
- set_bit(BDI_writeback_running, &wb->bdi->state);
- while ((work = get_next_work_item(bdi)) != NULL) {
+ set_bit(WB_writeback_running, &wb->state);
+ while ((work = get_next_work_item(wb)) != NULL) {
+ struct wb_completion *done = work->done;
+ bool need_wake_up = false;
- trace_writeback_exec(bdi, work);
+ trace_writeback_exec(wb->bdi, work);
wrote += wb_writeback(wb, work);
- /*
- * Notify the caller of completion if this is a synchronous
- * work item, otherwise just free it.
- */
- if (work->done)
- complete(work->done);
- else
+ if (work->single_wait) {
+ WARN_ON_ONCE(work->auto_free);
+ /* paired w/ rmb in wb_wait_for_single_work() */
+ smp_wmb();
+ work->single_done = 1;
+ need_wake_up = true;
+ } else if (work->auto_free) {
kfree(work);
+ }
+
+ if (done && atomic_dec_and_test(&done->cnt))
+ need_wake_up = true;
+
+ if (need_wake_up)
+ wake_up_all(&wb->bdi->wb_waitq);
}
/*
@@ -1079,7 +1821,7 @@ static long wb_do_writeback(struct bdi_writeback *wb)
*/
wrote += wb_check_old_data_flush(wb);
wrote += wb_check_background_flush(wb);
- clear_bit(BDI_writeback_running, &wb->bdi->state);
+ clear_bit(WB_writeback_running, &wb->state);
return wrote;
}
@@ -1088,43 +1830,42 @@ static long wb_do_writeback(struct bdi_writeback *wb)
* Handle writeback of dirty data for the device backed by this bdi. Also
* reschedules periodically and does kupdated style flushing.
*/
-void bdi_writeback_workfn(struct work_struct *work)
+void wb_workfn(struct work_struct *work)
{
struct bdi_writeback *wb = container_of(to_delayed_work(work),
struct bdi_writeback, dwork);
- struct backing_dev_info *bdi = wb->bdi;
long pages_written;
- set_worker_desc("flush-%s", dev_name(bdi->dev));
+ set_worker_desc("flush-%s", dev_name(wb->bdi->dev));
current->flags |= PF_SWAPWRITE;
if (likely(!current_is_workqueue_rescuer() ||
- !test_bit(BDI_registered, &bdi->state))) {
+ !test_bit(WB_registered, &wb->state))) {
/*
- * The normal path. Keep writing back @bdi until its
+ * The normal path. Keep writing back @wb until its
* work_list is empty. Note that this path is also taken
- * if @bdi is shutting down even when we're running off the
+ * if @wb is shutting down even when we're running off the
* rescuer as work_list needs to be drained.
*/
do {
pages_written = wb_do_writeback(wb);
trace_writeback_pages_written(pages_written);
- } while (!list_empty(&bdi->work_list));
+ } while (!list_empty(&wb->work_list));
} else {
/*
* bdi_wq can't get enough workers and we're running off
* the emergency worker. Don't hog it. Hopefully, 1024 is
* enough for efficient IO.
*/
- pages_written = writeback_inodes_wb(&bdi->wb, 1024,
+ pages_written = writeback_inodes_wb(wb, 1024,
WB_REASON_FORKER_THREAD);
trace_writeback_pages_written(pages_written);
}
- if (!list_empty(&bdi->work_list))
+ if (!list_empty(&wb->work_list))
mod_delayed_work(bdi_wq, &wb->dwork, 0);
else if (wb_has_dirty_io(wb) && dirty_writeback_interval)
- bdi_wakeup_thread_delayed(bdi);
+ wb_wakeup_delayed(wb);
current->flags &= ~PF_SWAPWRITE;
}
@@ -1142,9 +1883,15 @@ void wakeup_flusher_threads(long nr_pages, enum wb_reason reason)
rcu_read_lock();
list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) {
+ struct bdi_writeback *wb;
+ struct wb_iter iter;
+
if (!bdi_has_dirty_io(bdi))
continue;
- __bdi_start_writeback(bdi, nr_pages, false, reason);
+
+ bdi_for_each_wb(wb, bdi, &iter, 0)
+ wb_start_writeback(wb, wb_split_bdi_pages(wb, nr_pages),
+ false, reason);
}
rcu_read_unlock();
}
@@ -1173,9 +1920,12 @@ static void wakeup_dirtytime_writeback(struct work_struct *w)
rcu_read_lock();
list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) {
- if (list_empty(&bdi->wb.b_dirty_time))
- continue;
- bdi_wakeup_thread(bdi);
+ struct bdi_writeback *wb;
+ struct wb_iter iter;
+
+ bdi_for_each_wb(wb, bdi, &iter, 0)
+ if (!list_empty(&bdi->wb.b_dirty_time))
+ wb_wakeup(&bdi->wb);
}
rcu_read_unlock();
schedule_delayed_work(&dirtytime_work, dirtytime_expire_interval * HZ);
@@ -1249,7 +1999,6 @@ static noinline void block_dump___mark_inode_dirty(struct inode *inode)
void __mark_inode_dirty(struct inode *inode, int flags)
{
struct super_block *sb = inode->i_sb;
- struct backing_dev_info *bdi = NULL;
int dirtytime;
trace_writeback_mark_inode_dirty(inode, flags);
@@ -1289,6 +2038,8 @@ void __mark_inode_dirty(struct inode *inode, int flags)
if ((inode->i_state & flags) != flags) {
const int was_dirty = inode->i_state & I_DIRTY;
+ inode_attach_wb(inode, NULL);
+
if (flags & I_DIRTY_INODE)
inode->i_state &= ~I_DIRTY_TIME;
inode->i_state |= flags;
@@ -1317,38 +2068,39 @@ void __mark_inode_dirty(struct inode *inode, int flags)
* reposition it (that would break b_dirty time-ordering).
*/
if (!was_dirty) {
+ struct bdi_writeback *wb;
+ struct list_head *dirty_list;
bool wakeup_bdi = false;
- bdi = inode_to_bdi(inode);
- spin_unlock(&inode->i_lock);
- spin_lock(&bdi->wb.list_lock);
- if (bdi_cap_writeback_dirty(bdi)) {
- WARN(!test_bit(BDI_registered, &bdi->state),
- "bdi-%s not registered\n", bdi->name);
+ wb = locked_inode_to_wb_and_lock_list(inode);
- /*
- * If this is the first dirty inode for this
- * bdi, we have to wake-up the corresponding
- * bdi thread to make sure background
- * write-back happens later.
- */
- if (!wb_has_dirty_io(&bdi->wb))
- wakeup_bdi = true;
- }
+ WARN(bdi_cap_writeback_dirty(wb->bdi) &&
+ !test_bit(WB_registered, &wb->state),
+ "bdi-%s not registered\n", wb->bdi->name);
inode->dirtied_when = jiffies;
if (dirtytime)
inode->dirtied_time_when = jiffies;
+
if (inode->i_state & (I_DIRTY_INODE | I_DIRTY_PAGES))
- list_move(&inode->i_wb_list, &bdi->wb.b_dirty);
+ dirty_list = &wb->b_dirty;
else
- list_move(&inode->i_wb_list,
- &bdi->wb.b_dirty_time);
- spin_unlock(&bdi->wb.list_lock);
+ dirty_list = &wb->b_dirty_time;
+
+ wakeup_bdi = inode_wb_list_move_locked(inode, wb,
+ dirty_list);
+
+ spin_unlock(&wb->list_lock);
trace_writeback_dirty_inode_enqueue(inode);
- if (wakeup_bdi)
- bdi_wakeup_thread_delayed(bdi);
+ /*
+ * If this is the first dirty inode for this bdi,
+ * we have to wake-up the corresponding bdi thread
+ * to make sure background write-back happens
+ * later.
+ */
+ if (bdi_cap_writeback_dirty(wb->bdi) && wakeup_bdi)
+ wb_wakeup_delayed(wb);
return;
}
}
@@ -1411,6 +2163,28 @@ static void wait_sb_inodes(struct super_block *sb)
iput(old_inode);
}
+static void __writeback_inodes_sb_nr(struct super_block *sb, unsigned long nr,
+ enum wb_reason reason, bool skip_if_busy)
+{
+ DEFINE_WB_COMPLETION_ONSTACK(done);
+ struct wb_writeback_work work = {
+ .sb = sb,
+ .sync_mode = WB_SYNC_NONE,
+ .tagged_writepages = 1,
+ .done = &done,
+ .nr_pages = nr,
+ .reason = reason,
+ };
+ struct backing_dev_info *bdi = sb->s_bdi;
+
+ if (!bdi_has_dirty_io(bdi) || bdi == &noop_backing_dev_info)
+ return;
+ WARN_ON(!rwsem_is_locked(&sb->s_umount));
+
+ bdi_split_work_to_wbs(sb->s_bdi, &work, skip_if_busy);
+ wb_wait_for_completion(bdi, &done);
+}
+
/**
* writeback_inodes_sb_nr - writeback dirty inodes from given super_block
* @sb: the superblock
@@ -1425,21 +2199,7 @@ void writeback_inodes_sb_nr(struct super_block *sb,
unsigned long nr,
enum wb_reason reason)
{
- DECLARE_COMPLETION_ONSTACK(done);
- struct wb_writeback_work work = {
- .sb = sb,
- .sync_mode = WB_SYNC_NONE,
- .tagged_writepages = 1,
- .done = &done,
- .nr_pages = nr,
- .reason = reason,
- };
-
- if (sb->s_bdi == &noop_backing_dev_info)
- return;
- WARN_ON(!rwsem_is_locked(&sb->s_umount));
- bdi_queue_work(sb->s_bdi, &work);
- wait_for_completion(&done);
+ __writeback_inodes_sb_nr(sb, nr, reason, false);
}
EXPORT_SYMBOL(writeback_inodes_sb_nr);
@@ -1467,19 +2227,15 @@ EXPORT_SYMBOL(writeback_inodes_sb);
* Invoke writeback_inodes_sb_nr if no writeback is currently underway.
* Returns 1 if writeback was started, 0 if not.
*/
-int try_to_writeback_inodes_sb_nr(struct super_block *sb,
- unsigned long nr,
- enum wb_reason reason)
+bool try_to_writeback_inodes_sb_nr(struct super_block *sb, unsigned long nr,
+ enum wb_reason reason)
{
- if (writeback_in_progress(sb->s_bdi))
- return 1;
-
if (!down_read_trylock(&sb->s_umount))
- return 0;
+ return false;
- writeback_inodes_sb_nr(sb, nr, reason);
+ __writeback_inodes_sb_nr(sb, nr, reason, true);
up_read(&sb->s_umount);
- return 1;
+ return true;
}
EXPORT_SYMBOL(try_to_writeback_inodes_sb_nr);
@@ -1491,7 +2247,7 @@ EXPORT_SYMBOL(try_to_writeback_inodes_sb_nr);
* Implement by try_to_writeback_inodes_sb_nr()
* Returns 1 if writeback was started, 0 if not.
*/
-int try_to_writeback_inodes_sb(struct super_block *sb, enum wb_reason reason)
+bool try_to_writeback_inodes_sb(struct super_block *sb, enum wb_reason reason)
{
return try_to_writeback_inodes_sb_nr(sb, get_nr_dirty_pages(), reason);
}
@@ -1506,7 +2262,7 @@ EXPORT_SYMBOL(try_to_writeback_inodes_sb);
*/
void sync_inodes_sb(struct super_block *sb)
{
- DECLARE_COMPLETION_ONSTACK(done);
+ DEFINE_WB_COMPLETION_ONSTACK(done);
struct wb_writeback_work work = {
.sb = sb,
.sync_mode = WB_SYNC_ALL,
@@ -1516,14 +2272,15 @@ void sync_inodes_sb(struct super_block *sb)
.reason = WB_REASON_SYNC,
.for_sync = 1,
};
+ struct backing_dev_info *bdi = sb->s_bdi;
/* Nothing to do? */
- if (sb->s_bdi == &noop_backing_dev_info)
+ if (!bdi_has_dirty_io(bdi) || bdi == &noop_backing_dev_info)
return;
WARN_ON(!rwsem_is_locked(&sb->s_umount));
- bdi_queue_work(sb->s_bdi, &work);
- wait_for_completion(&done);
+ bdi_split_work_to_wbs(bdi, &work, false);
+ wb_wait_for_completion(bdi, &done);
wait_sb_inodes(sb);
}
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 5ef05b5c4cff..8c5e2fa68835 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1445,9 +1445,9 @@ static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req)
list_del(&req->writepages_entry);
for (i = 0; i < req->num_pages; i++) {
- dec_bdi_stat(bdi, BDI_WRITEBACK);
+ dec_wb_stat(&bdi->wb, WB_WRITEBACK);
dec_zone_page_state(req->pages[i], NR_WRITEBACK_TEMP);
- bdi_writeout_inc(bdi);
+ wb_writeout_inc(&bdi->wb);
}
wake_up(&fi->page_waitq);
}
@@ -1634,7 +1634,7 @@ static int fuse_writepage_locked(struct page *page)
req->end = fuse_writepage_end;
req->inode = inode;
- inc_bdi_stat(inode_to_bdi(inode), BDI_WRITEBACK);
+ inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK);
inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
spin_lock(&fc->lock);
@@ -1749,9 +1749,9 @@ static bool fuse_writepage_in_flight(struct fuse_req *new_req,
copy_highpage(old_req->pages[0], page);
spin_unlock(&fc->lock);
- dec_bdi_stat(bdi, BDI_WRITEBACK);
+ dec_wb_stat(&bdi->wb, WB_WRITEBACK);
dec_zone_page_state(page, NR_WRITEBACK_TEMP);
- bdi_writeout_inc(bdi);
+ wb_writeout_inc(&bdi->wb);
fuse_writepage_free(fc, new_req);
fuse_request_free(new_req);
goto out;
@@ -1848,7 +1848,7 @@ static int fuse_writepages_fill(struct page *page,
req->page_descs[req->num_pages].offset = 0;
req->page_descs[req->num_pages].length = PAGE_SIZE;
- inc_bdi_stat(inode_to_bdi(inode), BDI_WRITEBACK);
+ inc_wb_stat(&inode_to_bdi(inode)->wb, WB_WRITEBACK);
inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP);
err = 0;
diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 859c6edbf81a..2982445947e1 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -748,7 +748,7 @@ static int gfs2_write_inode(struct inode *inode, struct writeback_control *wbc)
if (wbc->sync_mode == WB_SYNC_ALL)
gfs2_log_flush(GFS2_SB(inode), ip->i_gl, NORMAL_FLUSH);
- if (bdi->dirty_exceeded)
+ if (bdi->wb.dirty_exceeded)
gfs2_ail1_flush(sdp, wbc);
else
filemap_fdatawrite(metamapping);
diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index eee7206c38d1..55c03b9e9070 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -14,6 +14,7 @@
#include <linux/module.h>
#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
#include <linux/mount.h>
#include <linux/init.h>
#include <linux/nls.h>
diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c
index 593af2fdcc2d..7302d96ae8bf 100644
--- a/fs/hfsplus/super.c
+++ b/fs/hfsplus/super.c
@@ -11,6 +11,7 @@
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/vfs.h>
diff --git a/fs/inode.c b/fs/inode.c
index e8d62688ed91..069721f0cc0e 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -224,6 +224,7 @@ EXPORT_SYMBOL(free_inode_nonrcu);
void __destroy_inode(struct inode *inode)
{
BUG_ON(inode_has_buffers(inode));
+ inode_detach_wb(inode);
security_inode_free(inode);
fsnotify_inode_delete(inode);
locks_free_lock_context(inode->i_flctx);
diff --git a/fs/mpage.c b/fs/mpage.c
index 3e79220babac..ca0244b69de8 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -605,6 +605,8 @@ alloc_new:
bio_get_nr_vecs(bdev), GFP_NOFS|__GFP_HIGH);
if (bio == NULL)
goto confused;
+
+ wbc_init_bio(wbc, bio);
}
/*
@@ -612,6 +614,7 @@ alloc_new:
* the confused fail path above (OOM) will be very confused when
* it finds all bh marked clean (i.e. it will not write anything)
*/
+ wbc_account_io(wbc, page, PAGE_SIZE);
length = first_unmapped << blkbits;
if (bio_add_page(bio, page, length, 0) < length) {
bio = mpage_bio_submit(WRITE, bio);
diff --git a/fs/nfs/filelayout/filelayout.c b/fs/nfs/filelayout/filelayout.c
index a46bf6de9ce4..b34f2e228601 100644
--- a/fs/nfs/filelayout/filelayout.c
+++ b/fs/nfs/filelayout/filelayout.c
@@ -32,6 +32,7 @@
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/module.h>
+#include <linux/backing-dev.h>
#include <linux/sunrpc/metrics.h>
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 9e6475bc5ba2..7e3c4604bea8 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -607,7 +607,7 @@ void nfs_mark_page_unstable(struct page *page)
struct inode *inode = page_file_mapping(page)->host;
inc_zone_page_state(page, NR_UNSTABLE_NFS);
- inc_bdi_stat(inode_to_bdi(inode), BDI_RECLAIMABLE);
+ inc_wb_stat(&inode_to_bdi(inode)->wb, WB_RECLAIMABLE);
__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
}
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index dfc19f1575a1..e6c262555e08 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -853,7 +853,8 @@ static void
nfs_clear_page_commit(struct page *page)
{
dec_zone_page_state(page, NR_UNSTABLE_NFS);
- dec_bdi_stat(inode_to_bdi(page_file_mapping(page)->host), BDI_RECLAIMABLE);
+ dec_wb_stat(&inode_to_bdi(page_file_mapping(page)->host)->wb,
+ WB_RECLAIMABLE);
}
/* Called holding inode (/cinfo) lock */
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index fbfadb289e62..719f7f4c7a37 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -37,6 +37,7 @@
#include <linux/falloc.h>
#include <linux/quotaops.h>
#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
#include <cluster/masklog.h>
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index 0111ad0466ed..3e0af317fcc3 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -21,6 +21,7 @@
#include "xattr.h"
#include <linux/init.h>
#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
#include <linux/buffer_head.h>
#include <linux/exportfs.h>
#include <linux/quotaops.h>
diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index b3bc3e7ae79d..098508a93c7b 100644
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -80,6 +80,7 @@
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
#include <linux/init.h>
#include <linux/parser.h>
#include <linux/buffer_head.h>
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 095f94c2d8b5..e5099f268032 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -1873,6 +1873,7 @@ xfs_vm_set_page_dirty(
loff_t end_offset;
loff_t offset;
int newly_dirty;
+ struct mem_cgroup *memcg;
if (unlikely(!mapping))
return !TestSetPageDirty(page);
@@ -1892,6 +1893,11 @@ xfs_vm_set_page_dirty(
offset += 1 << inode->i_blkbits;
} while (bh != head);
}
+ /*
+ * Use mem_group_begin_page_stat() to keep PageDirty synchronized with
+ * per-memcg dirty page counters.
+ */
+ memcg = mem_cgroup_begin_page_stat(page);
newly_dirty = !TestSetPageDirty(page);
spin_unlock(&mapping->private_lock);
@@ -1902,13 +1908,15 @@ xfs_vm_set_page_dirty(
spin_lock_irqsave(&mapping->tree_lock, flags);
if (page->mapping) { /* Race with truncate? */
WARN_ON_ONCE(!PageUptodate(page));
- account_page_dirtied(page, mapping);
+ account_page_dirtied(page, mapping, memcg);
radix_tree_tag_set(&mapping->page_tree,
page_index(page), PAGECACHE_TAG_DIRTY);
}
spin_unlock_irqrestore(&mapping->tree_lock, flags);
- __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
}
+ mem_cgroup_end_page_stat(memcg);
+ if (newly_dirty)
+ __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
return newly_dirty;
}
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 3b7591224f4a..7c62fca53e2f 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -41,6 +41,7 @@
#include <linux/dcache.h>
#include <linux/falloc.h>
#include <linux/pagevec.h>
+#include <linux/backing-dev.h>
static const struct vm_operations_struct xfs_file_vm_ops;