f2fs: call f2fs_balance_fs only when node was changed

If user tries to update or read data, we don't need to call f2fs_balance_fs
which triggers f2fs_gc, which increases unnecessary long latency.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

3 files changed, 35 insertions, 21 deletions

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 82ecaa30fd77..958d8261b258 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -509,7 +509,6 @@ static void __allocate_data_blocks(struct inode *inode, loff_t offset,
         u64 end_offset;
 
         while (len) {
-                f2fs_balance_fs(sbi);
                 f2fs_lock_op(sbi);
 
                 /* When reading holes, we need its node page */
@@ -542,6 +541,9 @@ static void __allocate_data_blocks(struct inode *inode, loff_t offset,
 
                 f2fs_put_dnode(&dn);
                 f2fs_unlock_op(sbi);
+
+                if (dn.node_changed)
+                        f2fs_balance_fs(sbi);
         }
         return;
 
@@ -551,6 +553,8 @@ sync_out:
         f2fs_put_dnode(&dn);
 out:
         f2fs_unlock_op(sbi);
+        if (dn.node_changed)
+                f2fs_balance_fs(sbi);
         return;
 }
 
@@ -649,6 +653,8 @@ get_next:
 
                 if (create) {
                         f2fs_unlock_op(sbi);
+                        if (dn.node_changed)
+                                f2fs_balance_fs(sbi);
                         f2fs_lock_op(sbi);
                 }
 
@@ -706,8 +712,11 @@ sync_out:
 put_out:
         f2fs_put_dnode(&dn);
 unlock_out:
-        if (create)
+        if (create) {
                 f2fs_unlock_op(sbi);
+                if (dn.node_changed)
+                        f2fs_balance_fs(sbi);
+        }
 out:
         trace_f2fs_map_blocks(inode, map, err);
         return err;
@@ -1415,8 +1424,6 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
 
         trace_f2fs_write_begin(inode, pos, len, flags);
 
-        f2fs_balance_fs(sbi);
-
         /*
          * We should check this at this moment to avoid deadlock on inode page
          * and #0 page. The locking rule for inline_data conversion should be:
@@ -1466,6 +1473,17 @@ put_next:
         f2fs_put_dnode(&dn);
         f2fs_unlock_op(sbi);
 
+        if (dn.node_changed && has_not_enough_free_secs(sbi, 0)) {
+                unlock_page(page);
+                f2fs_balance_fs(sbi);
+                lock_page(page);
+                if (page->mapping != mapping) {
+                        /* The page got truncated from under us */
+                        f2fs_put_page(page, 1);
+                        goto repeat;
+                }
+        }
+
         f2fs_wait_on_page_writeback(page, DATA);
 
         /* wait for GCed encrypted page writeback */
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index f2effe18d3c5..888ce4765779 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -40,8 +40,6 @@ static int f2fs_vm_page_mkwrite(struct vm_area_struct *vma,
         struct dnode_of_data dn;
         int err;
 
-        f2fs_balance_fs(sbi);
-
         sb_start_pagefault(inode->i_sb);
 
         f2fs_bug_on(sbi, f2fs_has_inline_data(inode));
@@ -57,6 +55,9 @@ static int f2fs_vm_page_mkwrite(struct vm_area_struct *vma,
         f2fs_put_dnode(&dn);
         f2fs_unlock_op(sbi);
 
+        if (dn.node_changed)
+                f2fs_balance_fs(sbi);
+
         file_update_time(vma->vm_file);
         lock_page(page);
         if (unlikely(page->mapping != inode->i_mapping ||
@@ -233,9 +234,6 @@ int f2fs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
                 goto out;
         }
 go_write:
-        /* guarantee free sections for fsync */
-        f2fs_balance_fs(sbi);
-
         /*
          * Both of fdatasync() and fsync() are able to be recovered from
          * sudden-power-off.
@@ -267,6 +265,8 @@ sync_nodes:
         if (need_inode_block_update(sbi, ino)) {
                 mark_inode_dirty_sync(inode);
                 f2fs_write_inode(inode, NULL);
+
+                f2fs_balance_fs(sbi);
                 goto sync_nodes;
         }
 
@@ -945,8 +945,6 @@ static int f2fs_collapse_range(struct inode *inode, loff_t offset, loff_t len)
         if (offset & (F2FS_BLKSIZE - 1) || len & (F2FS_BLKSIZE - 1))
                 return -EINVAL;
 
-        f2fs_balance_fs(F2FS_I_SB(inode));
-
         ret = f2fs_convert_inline_inode(inode);
         if (ret)
                 return ret;
@@ -993,8 +991,6 @@ static int f2fs_zero_range(struct inode *inode, loff_t offset, loff_t len,
         if (ret)
                 return ret;
 
-        f2fs_balance_fs(sbi);
-
         ret = f2fs_convert_inline_inode(inode);
         if (ret)
                 return ret;
@@ -1104,12 +1100,12 @@ static int f2fs_insert_range(struct inode *inode, loff_t offset, loff_t len)
         if (offset & (F2FS_BLKSIZE - 1) || len & (F2FS_BLKSIZE - 1))
                 return -EINVAL;
 
-        f2fs_balance_fs(sbi);
-
         ret = f2fs_convert_inline_inode(inode);
         if (ret)
                 return ret;
 
+        f2fs_balance_fs(sbi);
+
         ret = truncate_blocks(inode, i_size_read(inode), true);
         if (ret)
                 return ret;
@@ -1152,8 +1148,6 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
         loff_t off_start, off_end;
         int ret = 0;
 
-        f2fs_balance_fs(sbi);
-
         ret = inode_newsize_ok(inode, (len + offset));
         if (ret)
                 return ret;
@@ -1162,6 +1156,8 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
         if (ret)
                 return ret;
 
+        f2fs_balance_fs(sbi);
+
         pg_start = ((unsigned long long) offset) >> PAGE_CACHE_SHIFT;
         pg_end = ((unsigned long long) offset + len) >> PAGE_CACHE_SHIFT;
 
@@ -1349,8 +1345,6 @@ static int f2fs_ioc_start_atomic_write(struct file *filp)
         if (!inode_owner_or_capable(inode))
                 return -EACCES;
 
-        f2fs_balance_fs(F2FS_I_SB(inode));
-
         if (f2fs_is_atomic_file(inode))
                 return 0;
 
@@ -1437,8 +1431,6 @@ static int f2fs_ioc_abort_volatile_write(struct file *filp)
         if (ret)
                 return ret;
 
-        f2fs_balance_fs(F2FS_I_SB(inode));
-
         clear_inode_flag(F2FS_I(inode), FI_ATOMIC_FILE);
         clear_inode_flag(F2FS_I(inode), FI_VOLATILE_FILE);
         commit_inmem_pages(inode, true);
diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index 8090854dd29c..c24e5d93720d 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -202,6 +202,10 @@ out:
         f2fs_unlock_op(sbi);
 
         f2fs_put_page(page, 1);
+
+        if (dn.node_changed)
+                f2fs_balance_fs(sbi);
+
         return err;
 }