Merge tag 'f2fs-for-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs

Pull f2fs updates from Jaegeuk Kim:
 "This patch-set includes the following major enhancement patches.
   - introduce a new gloabl lock scheme
   - add tracepoints on several major functions
   - fix the overall cleaning process focused on victim selection
   - apply the block plugging to merge IOs as much as possible
   - enhance management of free nids and its list
   - enhance the readahead mode for node pages
   - address several cretical deadlock conditions
   - reduce lock_page calls

  The other minor bug fixes and enhancements are as follows.
   - calculation mistakes: overflow
   - bio types: READ, READA, and READ_SYNC
   - fix the recovery flow, data races, and null pointer errors"

* tag 'f2fs-for-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (68 commits)
  f2fs: cover free_nid management with spin_lock
  f2fs: optimize scan_nat_page()
  f2fs: code cleanup for scan_nat_page() and build_free_nids()
  f2fs: bugfix for alloc_nid_failed()
  f2fs: recover when journal contains deleted files
  f2fs: continue to mount after failing recovery
  f2fs: avoid deadlock during evict after f2fs_gc
  f2fs: modify the number of issued pages to merge IOs
  f2fs: remove useless #include <linux/proc_fs.h> as we're now using sysfs as debug entry.
  f2fs: fix inconsistent using of NM_WOUT_THRESHOLD
  f2fs: check truncation of mapping after lock_page
  f2fs: enhance alloc_nid and build_free_nids flows
  f2fs: add a tracepoint on f2fs_new_inode
  f2fs: check nid == 0 in add_free_nid
  f2fs: add REQ_META about metadata requests for submit
  f2fs: give a chance to merge IOs by IO scheduler
  f2fs: avoid frequent background GC
  f2fs: add tracepoints to debug checkpoint request
  f2fs: add tracepoints for write page operations
  f2fs: add tracepoints to debug the block allocation
  ...

1 files changed, 116 insertions, 86 deletions

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index d0ed4ba4b61b..91ff93b0b0f4 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -22,6 +22,7 @@
 #include "f2fs.h"
 #include "node.h"
 #include "segment.h"
+#include <trace/events/f2fs.h>
 
 /*
  * Lock ordering for the change of data block address:
@@ -55,6 +56,8 @@ int reserve_new_block(struct dnode_of_data *dn)
 	if (!inc_valid_block_count(sbi, dn->inode, 1))
 		return -ENOSPC;
 
+	trace_f2fs_reserve_new_block(dn->inode, dn->nid, dn->ofs_in_node);
+
 	__set_data_blkaddr(dn, NEW_ADDR);
 	dn->data_blkaddr = NEW_ADDR;
 	sync_inode_page(dn);
@@ -134,7 +137,7 @@ void update_extent_cache(block_t blk_addr, struct dnode_of_data *dn)
 		goto end_update;
 	}
 
-	/* Frone merge */
+	/* Front merge */
 	if (fofs == start_fofs - 1 && blk_addr == start_blkaddr - 1) {
 		fi->ext.fofs--;
 		fi->ext.blk_addr--;
@@ -170,7 +173,7 @@ end_update:
 	return;
 }
 
-struct page *find_data_page(struct inode *inode, pgoff_t index)
+struct page *find_data_page(struct inode *inode, pgoff_t index, bool sync)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	struct address_space *mapping = inode->i_mapping;
@@ -184,7 +187,7 @@ struct page *find_data_page(struct inode *inode, pgoff_t index)
 	f2fs_put_page(page, 0);
 
 	set_new_dnode(&dn, inode, NULL, NULL, 0);
-	err = get_dnode_of_data(&dn, index, RDONLY_NODE);
+	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
 	if (err)
 		return ERR_PTR(err);
 	f2fs_put_dnode(&dn);
@@ -200,12 +203,20 @@ struct page *find_data_page(struct inode *inode, pgoff_t index)
 	if (!page)
 		return ERR_PTR(-ENOMEM);
 
-	err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
-	if (err) {
-		f2fs_put_page(page, 1);
-		return ERR_PTR(err);
+	if (PageUptodate(page)) {
+		unlock_page(page);
+		return page;
+	}
+
+	err = f2fs_readpage(sbi, page, dn.data_blkaddr,
+					sync ? READ_SYNC : READA);
+	if (sync) {
+		wait_on_page_locked(page);
+		if (!PageUptodate(page)) {
+			f2fs_put_page(page, 0);
+			return ERR_PTR(-EIO);
+		}
 	}
-	unlock_page(page);
 	return page;
 }
 
@@ -223,14 +234,14 @@ struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
 	int err;
 
 	set_new_dnode(&dn, inode, NULL, NULL, 0);
-	err = get_dnode_of_data(&dn, index, RDONLY_NODE);
+	err = get_dnode_of_data(&dn, index, LOOKUP_NODE);
 	if (err)
 		return ERR_PTR(err);
 	f2fs_put_dnode(&dn);
 
 	if (dn.data_blkaddr == NULL_ADDR)
 		return ERR_PTR(-ENOENT);
-
+repeat:
 	page = grab_cache_page(mapping, index);
 	if (!page)
 		return ERR_PTR(-ENOMEM);
@@ -242,9 +253,17 @@ struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
 	BUG_ON(dn.data_blkaddr == NULL_ADDR);
 
 	err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
-	if (err) {
-		f2fs_put_page(page, 1);
+	if (err)
 		return ERR_PTR(err);
+
+	lock_page(page);
+	if (!PageUptodate(page)) {
+		f2fs_put_page(page, 1);
+		return ERR_PTR(-EIO);
+	}
+	if (page->mapping != mapping) {
+		f2fs_put_page(page, 1);
+		goto repeat;
 	}
 	return page;
 }
@@ -252,6 +271,9 @@ struct page *get_lock_data_page(struct inode *inode, pgoff_t index)
 /*
  * Caller ensures that this data page is never allocated.
  * A new zero-filled data page is allocated in the page cache.
+ *
+ * Also, caller should grab and release a mutex by calling mutex_lock_op() and
+ * mutex_unlock_op().
  */
 struct page *get_new_data_page(struct inode *inode, pgoff_t index,
 						bool new_i_size)
@@ -263,7 +285,7 @@ struct page *get_new_data_page(struct inode *inode, pgoff_t index,
 	int err;
 
 	set_new_dnode(&dn, inode, NULL, NULL, 0);
-	err = get_dnode_of_data(&dn, index, 0);
+	err = get_dnode_of_data(&dn, index, ALLOC_NODE);
 	if (err)
 		return ERR_PTR(err);
 
@@ -274,7 +296,7 @@ struct page *get_new_data_page(struct inode *inode, pgoff_t index,
 		}
 	}
 	f2fs_put_dnode(&dn);
-
+repeat:
 	page = grab_cache_page(mapping, index);
 	if (!page)
 		return ERR_PTR(-ENOMEM);
@@ -284,14 +306,21 @@ struct page *get_new_data_page(struct inode *inode, pgoff_t index,
 
 	if (dn.data_blkaddr == NEW_ADDR) {
 		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
+		SetPageUptodate(page);
 	} else {
 		err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
-		if (err) {
-			f2fs_put_page(page, 1);
+		if (err)
 			return ERR_PTR(err);
+		lock_page(page);
+		if (!PageUptodate(page)) {
+			f2fs_put_page(page, 1);
+			return ERR_PTR(-EIO);
+		}
+		if (page->mapping != mapping) {
+			f2fs_put_page(page, 1);
+			goto repeat;
 		}
 	}
-	SetPageUptodate(page);
 
 	if (new_i_size &&
 		i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) {
@@ -326,21 +355,15 @@ static void read_end_io(struct bio *bio, int err)
 
 /*
  * Fill the locked page with data located in the block address.
- * Read operation is synchronous, and caller must unlock the page.
+ * Return unlocked page.
  */
 int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page,
 					block_t blk_addr, int type)
 {
 	struct block_device *bdev = sbi->sb->s_bdev;
-	bool sync = (type == READ_SYNC);
 	struct bio *bio;
 
-	/* This page can be already read by other threads */
-	if (PageUptodate(page)) {
-		if (!sync)
-			unlock_page(page);
-		return 0;
-	}
+	trace_f2fs_readpage(page, blk_addr, type);
 
 	down_read(&sbi->bio_sem);
 
@@ -355,18 +378,12 @@ int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page,
 		kfree(bio->bi_private);
 		bio_put(bio);
 		up_read(&sbi->bio_sem);
+		f2fs_put_page(page, 1);
 		return -EFAULT;
 	}
 
 	submit_bio(type, bio);
 	up_read(&sbi->bio_sem);
-
-	/* wait for read completion if sync */
-	if (sync) {
-		lock_page(page);
-		if (PageError(page))
-			return -EIO;
-	}
 	return 0;
 }
 
@@ -388,14 +405,18 @@ static int get_data_block_ro(struct inode *inode, sector_t iblock,
 	/* Get the page offset from the block offset(iblock) */
 	pgofs =	(pgoff_t)(iblock >> (PAGE_CACHE_SHIFT - blkbits));
 
-	if (check_extent_cache(inode, pgofs, bh_result))
+	if (check_extent_cache(inode, pgofs, bh_result)) {
+		trace_f2fs_get_data_block(inode, iblock, bh_result, 0);
 		return 0;
+	}
 
 	/* When reading holes, we need its node page */
 	set_new_dnode(&dn, inode, NULL, NULL, 0);
-	err = get_dnode_of_data(&dn, pgofs, RDONLY_NODE);
-	if (err)
+	err = get_dnode_of_data(&dn, pgofs, LOOKUP_NODE_RA);
+	if (err) {
+		trace_f2fs_get_data_block(inode, iblock, bh_result, err);
 		return (err == -ENOENT) ? 0 : err;
+	}
 
 	/* It does not support data allocation */
 	BUG_ON(create);
@@ -420,6 +441,7 @@ static int get_data_block_ro(struct inode *inode, sector_t iblock,
 		bh_result->b_size = (i << blkbits);
 	}
 	f2fs_put_dnode(&dn);
+	trace_f2fs_get_data_block(inode, iblock, bh_result, 0);
 	return 0;
 }
 
@@ -438,13 +460,12 @@ static int f2fs_read_data_pages(struct file *file,
 int do_write_data_page(struct page *page)
 {
 	struct inode *inode = page->mapping->host;
-	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 	block_t old_blk_addr, new_blk_addr;
 	struct dnode_of_data dn;
 	int err = 0;
 
 	set_new_dnode(&dn, inode, NULL, NULL, 0);
-	err = get_dnode_of_data(&dn, page->index, RDONLY_NODE);
+	err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
 	if (err)
 		return err;
 
@@ -468,8 +489,6 @@ int do_write_data_page(struct page *page)
 		write_data_page(inode, page, &dn,
 				old_blk_addr, &new_blk_addr);
 		update_extent_cache(new_blk_addr, &dn);
-		F2FS_I(inode)->data_version =
-			le64_to_cpu(F2FS_CKPT(sbi)->checkpoint_ver);
 	}
 out_writepage:
 	f2fs_put_dnode(&dn);
@@ -485,10 +504,11 @@ static int f2fs_write_data_page(struct page *page,
 	const pgoff_t end_index = ((unsigned long long) i_size)
 							>> PAGE_CACHE_SHIFT;
 	unsigned offset;
+	bool need_balance_fs = false;
 	int err = 0;
 
 	if (page->index < end_index)
-		goto out;
+		goto write;
 
 	/*
 	 * If the offset is out-of-range of file size,
@@ -500,50 +520,46 @@ static int f2fs_write_data_page(struct page *page,
 			dec_page_count(sbi, F2FS_DIRTY_DENTS);
 			inode_dec_dirty_dents(inode);
 		}
-		goto unlock_out;
+		goto out;
 	}
 
 	zero_user_segment(page, offset, PAGE_CACHE_SIZE);
-out:
-	if (sbi->por_doing)
-		goto redirty_out;
-
-	if (wbc->for_reclaim && !S_ISDIR(inode->i_mode) && !is_cold_data(page))
+write:
+	if (sbi->por_doing) {
+		err = AOP_WRITEPAGE_ACTIVATE;
 		goto redirty_out;
+	}
 
-	mutex_lock_op(sbi, DATA_WRITE);
+	/* Dentry blocks are controlled by checkpoint */
 	if (S_ISDIR(inode->i_mode)) {
 		dec_page_count(sbi, F2FS_DIRTY_DENTS);
 		inode_dec_dirty_dents(inode);
+		err = do_write_data_page(page);
+	} else {
+		int ilock = mutex_lock_op(sbi);
+		err = do_write_data_page(page);
+		mutex_unlock_op(sbi, ilock);
+		need_balance_fs = true;
 	}
-	err = do_write_data_page(page);
-	if (err && err != -ENOENT) {
-		wbc->pages_skipped++;
-		set_page_dirty(page);
-	}
-	mutex_unlock_op(sbi, DATA_WRITE);
+	if (err == -ENOENT)
+		goto out;
+	else if (err)
+		goto redirty_out;
 
 	if (wbc->for_reclaim)
 		f2fs_submit_bio(sbi, DATA, true);
 
-	if (err == -ENOENT)
-		goto unlock_out;
-
 	clear_cold_data(page);
+out:
 	unlock_page(page);
-
-	if (!wbc->for_reclaim && !S_ISDIR(inode->i_mode))
+	if (need_balance_fs)
 		f2fs_balance_fs(sbi);
 	return 0;
 
-unlock_out:
-	unlock_page(page);
-	return (err == -ENOENT) ? 0 : err;
-
 redirty_out:
 	wbc->pages_skipped++;
 	set_page_dirty(page);
-	return AOP_WRITEPAGE_ACTIVATE;
+	return err;
 }
 
 #define MAX_DESIRED_PAGES_WP	4096
@@ -562,19 +578,26 @@ static int f2fs_write_data_pages(struct address_space *mapping,
 {
 	struct inode *inode = mapping->host;
 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
+	bool locked = false;
 	int ret;
 	long excess_nrtw = 0, desired_nrtw;
 
+	/* deal with chardevs and other special file */
+	if (!mapping->a_ops->writepage)
+		return 0;
+
 	if (wbc->nr_to_write < MAX_DESIRED_PAGES_WP) {
 		desired_nrtw = MAX_DESIRED_PAGES_WP;
 		excess_nrtw = desired_nrtw - wbc->nr_to_write;
 		wbc->nr_to_write = desired_nrtw;
 	}
 
-	if (!S_ISDIR(inode->i_mode))
+	if (!S_ISDIR(inode->i_mode)) {
 		mutex_lock(&sbi->writepages);
+		locked = true;
+	}
 	ret = write_cache_pages(mapping, wbc, __f2fs_writepage, mapping);
-	if (!S_ISDIR(inode->i_mode))
+	if (locked)
 		mutex_unlock(&sbi->writepages);
 	f2fs_submit_bio(sbi, DATA, (wbc->sync_mode == WB_SYNC_ALL));
 
@@ -594,39 +617,33 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
 	pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT;
 	struct dnode_of_data dn;
 	int err = 0;
+	int ilock;
 
 	/* for nobh_write_end */
 	*fsdata = NULL;
 
 	f2fs_balance_fs(sbi);
-
+repeat:
 	page = grab_cache_page_write_begin(mapping, index, flags);
 	if (!page)
 		return -ENOMEM;
 	*pagep = page;
 
-	mutex_lock_op(sbi, DATA_NEW);
+	ilock = mutex_lock_op(sbi);
 
 	set_new_dnode(&dn, inode, NULL, NULL, 0);
-	err = get_dnode_of_data(&dn, index, 0);
-	if (err) {
-		mutex_unlock_op(sbi, DATA_NEW);
-		f2fs_put_page(page, 1);
-		return err;
-	}
+	err = get_dnode_of_data(&dn, index, ALLOC_NODE);
+	if (err)
+		goto err;
 
-	if (dn.data_blkaddr == NULL_ADDR) {
+	if (dn.data_blkaddr == NULL_ADDR)
 		err = reserve_new_block(&dn);
-		if (err) {
-			f2fs_put_dnode(&dn);
-			mutex_unlock_op(sbi, DATA_NEW);
-			f2fs_put_page(page, 1);
-			return err;
-		}
-	}
+
 	f2fs_put_dnode(&dn);
+	if (err)
+		goto err;
 
-	mutex_unlock_op(sbi, DATA_NEW);
+	mutex_unlock_op(sbi, ilock);
 
 	if ((len == PAGE_CACHE_SIZE) || PageUptodate(page))
 		return 0;
@@ -637,21 +654,34 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
 
 		/* Reading beyond i_size is simple: memset to zero */
 		zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE);
-		return 0;
+		goto out;
 	}
 
 	if (dn.data_blkaddr == NEW_ADDR) {
 		zero_user_segment(page, 0, PAGE_CACHE_SIZE);
 	} else {
 		err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC);
-		if (err) {
-			f2fs_put_page(page, 1);
+		if (err)
 			return err;
+		lock_page(page);
+		if (!PageUptodate(page)) {
+			f2fs_put_page(page, 1);
+			return -EIO;
+		}
+		if (page->mapping != mapping) {
+			f2fs_put_page(page, 1);
+			goto repeat;
 		}
 	}
+out:
 	SetPageUptodate(page);
 	clear_cold_data(page);
 	return 0;
+
+err:
+	mutex_unlock_op(sbi, ilock);
+	f2fs_put_page(page, 1);
+	return err;
 }
 
 static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb,
@@ -682,7 +712,7 @@ static void f2fs_invalidate_data_page(struct page *page, unsigned long offset)
 static int f2fs_release_data_page(struct page *page, gfp_t wait)
 {
 	ClearPagePrivate(page);
-	return 0;
+	return 1;
 }
 
 static int f2fs_set_data_page_dirty(struct page *page)