[PATCH v2 00/22] ext4 fast commit fixes

[PATCH v2 00/22] ext4 fast commit fixes

[Harshad Shirwadkar]

ext4: fast commit fixes

This patch series adds several code-only (no on disk format changes)
fixes for the fast commit code. I verified that there were no
regressions introduced by this patch series in xfstests auto and log
groups in fast_commit and 4k configurations.

Changes since V1:

- Broke couple of misc patches into separate patches
- Added a few new fixes:
   - atomic update of mount flags
   - no fast commits on aborted journal
   - Dropped confusing fast commit mount options
- Dropped jbd2_fc_init()

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>

Harshad Shirwadkar (22):
  ext4: describe fast_commit feature flags
  ext4: mark fc ineligible if inode gets evictied due to mem pressure
  ext4: drop redundant calls ext4_fc_track_range
  ext4: fixup ext4_fc_track_* functions' signature
  jbd2: rename j_maxlen to j_total_len and add jbd2_journal_max_txn_bufs
  ext4: clean up the JBD2 API that initializes fast commits
  jbd2: drop jbd2_fc_init documentation
  jbd2: don't use state lock during commit path
  jbd2: don't pass tid to jbd2_fc_end_commit_fallback()
  jbd2: add todo for a fast commit  performance optimization
  jbd2: don't touch buffer state until it is filled
  jbd2: don't read journal->j_commit_sequence without taking a lock
  ext4: dedpulicate the code to wait on inode that's being committed
  ext4: fix code documentatioon
  ext4: mark buf dirty before submitting fast commit buffer
  ext4: remove unnecessary fast commit calls from ext4_file_mmap
  ext4: fix inode dirty check in case of fast commits
  ext4: disable fast commit with data journalling
  ext4: issue fsdev cache flush before starting fast commit
  ext4: make s_mount_flags modifications atomic
  jbd2: don't start fast commit on aborted journal
  ext4: cleanup fast commit mount options

 Documentation/filesystems/ext4/journal.rst |   6 +
 Documentation/filesystems/ext4/super.rst   |   7 +
 Documentation/filesystems/journalling.rst  |   6 +-
 fs/ext4/ext4.h                             |  66 +++++---
 fs/ext4/extents.c                          |   7 +-
 fs/ext4/fast_commit.c                      | 169 +++++++++++----------
 fs/ext4/fast_commit.h                      |   6 +-
 fs/ext4/file.c                             |   6 +-
 fs/ext4/fsmap.c                            |   2 +-
 fs/ext4/fsync.c                            |   2 +-
 fs/ext4/inode.c                            |  19 +--
 fs/ext4/mballoc.c                          |   4 +-
 fs/ext4/namei.c                            |  61 ++++----
 fs/ext4/super.c                            |  43 +++---
 fs/jbd2/commit.c                           |  11 +-
 fs/jbd2/journal.c                          | 138 +++++++++--------
 fs/jbd2/recovery.c                         |   6 +-
 fs/ocfs2/journal.c                         |   2 +-
 include/linux/jbd2.h                       |  23 ++-
 include/trace/events/ext4.h                |  10 +-
 20 files changed, 328 insertions(+), 266 deletions(-)

-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 01/22] ext4: describe fast_commit feature flags

[Harshad Shirwadkar]

Fast commit feature has flags in the file system as well in JBD2. The
meaning of fast commit feature flags can get confusing. Update docs
and code to add more documentation about it.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
---
 Documentation/filesystems/ext4/journal.rst | 6 ++++++
 Documentation/filesystems/ext4/super.rst   | 7 +++++++
 fs/ext4/ext4.h                             | 7 +++++++
 3 files changed, 20 insertions(+)

diff --git a/Documentation/filesystems/ext4/journal.rst b/Documentation/filesystems/ext4/journal.rst
index 805a1e9ea3a5..849d5b119eb8 100644
--- a/Documentation/filesystems/ext4/journal.rst
+++ b/Documentation/filesystems/ext4/journal.rst
@@ -256,6 +256,10 @@ which is 1024 bytes long:
      - s\_padding2
      -
    * - 0x54
+     - \_\_be32
+     - s\_num\_fc\_blocks
+     - Number of fast commit blocks in the journal.
+   * - 0x58
      - \_\_u32
      - s\_padding[42]
      -
@@ -310,6 +314,8 @@ The journal incompat features are any combination of the following:
      - This journal uses v3 of the checksum on-disk format. This is the same as
        v2, but the journal block tag size is fixed regardless of the size of
        block numbers. (JBD2\_FEATURE\_INCOMPAT\_CSUM\_V3)
+   * - 0x20
+     - Journal has fast commit blocks. (JBD2\_FEATURE\_INCOMPAT\_FAST\_COMMIT)
 
 .. _jbd2_checksum_type:
 
diff --git a/Documentation/filesystems/ext4/super.rst b/Documentation/filesystems/ext4/super.rst
index 93e55d7c1d40..2eb1ab20498d 100644
--- a/Documentation/filesystems/ext4/super.rst
+++ b/Documentation/filesystems/ext4/super.rst
@@ -596,6 +596,13 @@ following:
      - Sparse Super Block, v2. If this flag is set, the SB field s\_backup\_bgs
        points to the two block groups that contain backup superblocks
        (COMPAT\_SPARSE\_SUPER2).
+   * - 0x400
+     - Fast commits supported. Although fast commits blocks are
+       backward incompatible, fast commit blocks are not always
+       present in the journal. If fast commit blocks are present in
+       the journal, JBD2 incompat feature
+       (JBD2\_FEATURE\_INCOMPAT\_FAST\_COMMIT) gets
+       set (COMPAT\_FAST\_COMMIT).
 
 .. _super_incompat:
 
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 2337e443fa30..12673f9ec880 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1875,6 +1875,13 @@ static inline bool ext4_verity_in_progress(struct inode *inode)
 #define EXT4_FEATURE_COMPAT_RESIZE_INODE	0x0010
 #define EXT4_FEATURE_COMPAT_DIR_INDEX		0x0020
 #define EXT4_FEATURE_COMPAT_SPARSE_SUPER2	0x0200
+/*
+ * The reason why "FAST_COMMIT" is a compat feature is that, FS becomes
+ * incompatible only if fast commit blocks are present in the FS. Since we
+ * clear the journal (and thus the fast commit blocks), we don't mark FS as
+ * incompatible. We also have a JBD2 incompat feature, which gets set when
+ * there are fast commit blocks present in the journal.
+ */
 #define EXT4_FEATURE_COMPAT_FAST_COMMIT		0x0400
 #define EXT4_FEATURE_COMPAT_STABLE_INODES	0x0800
 
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 02/22] ext4: mark fc ineligible if inode gets evictied due to mem pressure

[Harshad Shirwadkar]

If inode gets evicted due to memory pressure, we have to remove it
from the fast commit list. However, that inode may have uncommitted
changes that fast commits will lose. So, just fall back to full
commits in this case. Also, rename the fast commit ineligiblity reason
from "EXT4_FC_REASON_MEM" to "EXT4_FC_REASON_MEM_NOMEM" for better
expression.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/fast_commit.c       | 4 ++--
 fs/ext4/fast_commit.h       | 2 +-
 fs/ext4/inode.c             | 2 ++
 include/trace/events/ext4.h | 6 +++---
 4 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 8d43058386c3..48b7bc129392 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -384,7 +384,7 @@ static int __track_dentry_update(struct inode *inode, void *arg, bool update)
 	mutex_unlock(&ei->i_fc_lock);
 	node = kmem_cache_alloc(ext4_fc_dentry_cachep, GFP_NOFS);
 	if (!node) {
-		ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_MEM);
+		ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_NOMEM);
 		mutex_lock(&ei->i_fc_lock);
 		return -ENOMEM;
 	}
@@ -397,7 +397,7 @@ static int __track_dentry_update(struct inode *inode, void *arg, bool update)
 		if (!node->fcd_name.name) {
 			kmem_cache_free(ext4_fc_dentry_cachep, node);
 			ext4_fc_mark_ineligible(inode->i_sb,
-				EXT4_FC_REASON_MEM);
+				EXT4_FC_REASON_NOMEM);
 			mutex_lock(&ei->i_fc_lock);
 			return -ENOMEM;
 		}
diff --git a/fs/ext4/fast_commit.h b/fs/ext4/fast_commit.h
index 06907d485989..140fbb6af19e 100644
--- a/fs/ext4/fast_commit.h
+++ b/fs/ext4/fast_commit.h
@@ -100,7 +100,7 @@ enum {
 	EXT4_FC_REASON_XATTR = 0,
 	EXT4_FC_REASON_CROSS_RENAME,
 	EXT4_FC_REASON_JOURNAL_FLAG_CHANGE,
-	EXT4_FC_REASON_MEM,
+	EXT4_FC_REASON_NOMEM,
 	EXT4_FC_REASON_SWAP_BOOT,
 	EXT4_FC_REASON_RESIZE,
 	EXT4_FC_REASON_RENAME_DIR,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b96a18679a27..081b6a86b5db 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -327,6 +327,8 @@ void ext4_evict_inode(struct inode *inode)
 	ext4_xattr_inode_array_free(ea_inode_array);
 	return;
 no_delete:
+	if (!list_empty(&EXT4_I(inode)->i_fc_list))
+		ext4_fc_mark_ineligible(inode->i_sb, EXT4_FC_REASON_NOMEM);
 	ext4_clear_inode(inode);	/* We must guarantee clearing of inode... */
 }
 
diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index b14314fcf732..0f899d3b09d3 100644
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -100,7 +100,7 @@ TRACE_DEFINE_ENUM(ES_REFERENCED_B);
 		{ EXT4_FC_REASON_XATTR,		"XATTR"},		\
 		{ EXT4_FC_REASON_CROSS_RENAME,	"CROSS_RENAME"},	\
 		{ EXT4_FC_REASON_JOURNAL_FLAG_CHANGE, "JOURNAL_FLAG_CHANGE"}, \
-		{ EXT4_FC_REASON_MEM,	"NO_MEM"},			\
+		{ EXT4_FC_REASON_NOMEM,	"NO_MEM"},			\
 		{ EXT4_FC_REASON_SWAP_BOOT,	"SWAP_BOOT"},		\
 		{ EXT4_FC_REASON_RESIZE,	"RESIZE"},		\
 		{ EXT4_FC_REASON_RENAME_DIR,	"RENAME_DIR"},		\
@@ -2917,13 +2917,13 @@ TRACE_EVENT(ext4_fc_stats,
 		    ),
 
 	    TP_printk("dev %d:%d fc ineligible reasons:\n"
-		      "%s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s,%d; "
+		      "%s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d; "
 		      "num_commits:%ld, ineligible: %ld, numblks: %ld",
 		      MAJOR(__entry->dev), MINOR(__entry->dev),
 		      FC_REASON_NAME_STAT(EXT4_FC_REASON_XATTR),
 		      FC_REASON_NAME_STAT(EXT4_FC_REASON_CROSS_RENAME),
 		      FC_REASON_NAME_STAT(EXT4_FC_REASON_JOURNAL_FLAG_CHANGE),
-		      FC_REASON_NAME_STAT(EXT4_FC_REASON_MEM),
+		      FC_REASON_NAME_STAT(EXT4_FC_REASON_NOMEM),
 		      FC_REASON_NAME_STAT(EXT4_FC_REASON_SWAP_BOOT),
 		      FC_REASON_NAME_STAT(EXT4_FC_REASON_RESIZE),
 		      FC_REASON_NAME_STAT(EXT4_FC_REASON_RENAME_DIR),
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 03/22] ext4: drop redundant calls ext4_fc_track_range

[Harshad Shirwadkar]

ext4_fc_track_range() should only be called when blocks are added or
removed from an inode. So, the only places from where we need to call
this function are ext4_map_blocks(), punch hole, collapse / zero
range, truncate. Remove all the other redundant calls to ths function.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/extents.c | 5 -----
 fs/ext4/super.c   | 4 ----
 2 files changed, 9 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 559100f3e23c..1db762c770ca 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3723,7 +3723,6 @@ static int ext4_convert_unwritten_extents_endio(handle_t *handle,
 	err = ext4_ext_dirty(handle, inode, path + path->p_depth);
 out:
 	ext4_ext_show_leaf(inode, path);
-	ext4_fc_track_range(inode, ee_block, ee_block + ee_len - 1);
 	return err;
 }
 
@@ -3795,7 +3794,6 @@ convert_initialized_extent(handle_t *handle, struct inode *inode,
 	if (*allocated > map->m_len)
 		*allocated = map->m_len;
 	map->m_len = *allocated;
-	ext4_fc_track_range(inode, ee_block, ee_block + ee_len - 1);
 	return 0;
 }
 
@@ -4329,7 +4327,6 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 	map->m_len = ar.len;
 	allocated = map->m_len;
 	ext4_ext_show_leaf(inode, path);
-	ext4_fc_track_range(inode, map->m_lblk, map->m_lblk + map->m_len - 1);
 out:
 	ext4_ext_drop_refs(path);
 	kfree(path);
@@ -4651,8 +4648,6 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 		     FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
 		     FALLOC_FL_INSERT_RANGE))
 		return -EOPNOTSUPP;
-	ext4_fc_track_range(inode, offset >> blkbits,
-			(offset + len - 1) >> blkbits);
 
 	ext4_fc_start_update(inode);
 
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index d92de21212e9..804f9fc5bdbd 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -6561,10 +6561,6 @@ static ssize_t ext4_quota_write(struct super_block *sb, int type,
 	brelse(bh);
 out:
 	if (inode->i_size < off + len) {
-		ext4_fc_track_range(inode,
-			(inode->i_size > 0 ? inode->i_size - 1 : 0)
-				>> inode->i_sb->s_blocksize_bits,
-			(off + len) >> inode->i_sb->s_blocksize_bits);
 		i_size_write(inode, off + len);
 		EXT4_I(inode)->i_disksize = inode->i_size;
 		err2 = ext4_mark_inode_dirty(handle, inode);
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 04/22] ext4: fixup ext4_fc_track_* functions' signature

[Harshad Shirwadkar]

Firstly, pass handle to all ext4_fc_track_* functions and use
transaction id found in handle->h_transaction->h_tid for tracking fast
commit updates. Secondly, don't pass inode to
ext4_fc_track_link/create/unlink functions. inode can be found inside
these functions as d_inode(dentry). However, rename path is an
exeception. That's because in that case, we need inode that's not same
as d_inode(dentry). To handle that, add a couple of low-level wrapper
functions that take inode and dentry as arguments.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/ext4.h        | 16 +++++++-----
 fs/ext4/extents.c     |  2 +-
 fs/ext4/fast_commit.c | 48 +++++++++++++++++++++-------------
 fs/ext4/inode.c       | 10 +++----
 fs/ext4/namei.c       | 61 ++++++++++++++++++++-----------------------
 5 files changed, 74 insertions(+), 63 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 12673f9ec880..23f8edd4fb2a 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2750,12 +2750,16 @@ extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
 int ext4_fc_info_show(struct seq_file *seq, void *v);
 void ext4_fc_init(struct super_block *sb, journal_t *journal);
 void ext4_fc_init_inode(struct inode *inode);
-void ext4_fc_track_range(struct inode *inode, ext4_lblk_t start,
+void ext4_fc_track_range(handle_t *handle, struct inode *inode, ext4_lblk_t start,
 			 ext4_lblk_t end);
-void ext4_fc_track_unlink(struct inode *inode, struct dentry *dentry);
-void ext4_fc_track_link(struct inode *inode, struct dentry *dentry);
-void ext4_fc_track_create(struct inode *inode, struct dentry *dentry);
-void ext4_fc_track_inode(struct inode *inode);
+void __ext4_fc_track_unlink(handle_t *handle, struct inode *inode,
+	struct dentry *dentry);
+void __ext4_fc_track_link(handle_t *handle, struct inode *inode,
+	struct dentry *dentry);
+void ext4_fc_track_unlink(handle_t *handle, struct dentry *dentry);
+void ext4_fc_track_link(handle_t *handle, struct dentry *dentry);
+void ext4_fc_track_create(handle_t *handle, struct dentry *dentry);
+void ext4_fc_track_inode(handle_t *handle, struct inode *inode);
 void ext4_fc_mark_ineligible(struct super_block *sb, int reason);
 void ext4_fc_start_ineligible(struct super_block *sb, int reason);
 void ext4_fc_stop_ineligible(struct super_block *sb);
@@ -3471,7 +3475,7 @@ extern int ext4_handle_dirty_dirblock(handle_t *handle, struct inode *inode,
 extern int ext4_ci_compare(const struct inode *parent,
 			   const struct qstr *fname,
 			   const struct qstr *entry, bool quick);
-extern int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
+extern int __ext4_unlink(handle_t *handle, struct inode *dir, const struct qstr *d_name,
 			 struct inode *inode);
 extern int __ext4_link(struct inode *dir, struct inode *inode,
 		       struct dentry *dentry);
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 1db762c770ca..1bac0e237e7c 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4599,7 +4599,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
 	ret = ext4_mark_inode_dirty(handle, inode);
 	if (unlikely(ret))
 		goto out_handle;
-	ext4_fc_track_range(inode, offset >> inode->i_sb->s_blocksize_bits,
+	ext4_fc_track_range(handle, inode, offset >> inode->i_sb->s_blocksize_bits,
 			(offset + len - 1) >> inode->i_sb->s_blocksize_bits);
 	/* Zero out partial block at the edges of the range */
 	ret = ext4_zero_partial_blocks(handle, inode, offset, len);
diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 48b7bc129392..9399e9cccb7e 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -323,13 +323,14 @@ static inline int ext4_fc_is_ineligible(struct super_block *sb)
  * If enqueue is set, this function enqueues the inode in fast commit list.
  */
 static int ext4_fc_track_template(
-	struct inode *inode, int (*__fc_track_fn)(struct inode *, void *, bool),
+	handle_t *handle, struct inode *inode,
+	int (*__fc_track_fn)(struct inode *, void *, bool),
 	void *args, int enqueue)
 {
-	tid_t running_txn_tid;
 	bool update = false;
 	struct ext4_inode_info *ei = EXT4_I(inode);
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+	tid_t tid = 0;
 	int ret;
 
 	if (!test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT) ||
@@ -339,15 +340,13 @@ static int ext4_fc_track_template(
 	if (ext4_fc_is_ineligible(inode->i_sb))
 		return -EINVAL;
 
-	running_txn_tid = sbi->s_journal ?
-		sbi->s_journal->j_commit_sequence + 1 : 0;
-
+	tid = handle->h_transaction->t_tid;
 	mutex_lock(&ei->i_fc_lock);
-	if (running_txn_tid == ei->i_sync_tid) {
+	if (tid == ei->i_sync_tid) {
 		update = true;
 	} else {
 		ext4_fc_reset_inode(inode);
-		ei->i_sync_tid = running_txn_tid;
+		ei->i_sync_tid = tid;
 	}
 	ret = __fc_track_fn(inode, args, update);
 	mutex_unlock(&ei->i_fc_lock);
@@ -422,7 +421,8 @@ static int __track_dentry_update(struct inode *inode, void *arg, bool update)
 	return 0;
 }
 
-void ext4_fc_track_unlink(struct inode *inode, struct dentry *dentry)
+void __ext4_fc_track_unlink(handle_t *handle,
+		struct inode *inode, struct dentry *dentry)
 {
 	struct __track_dentry_update_args args;
 	int ret;
@@ -430,12 +430,18 @@ void ext4_fc_track_unlink(struct inode *inode, struct dentry *dentry)
 	args.dentry = dentry;
 	args.op = EXT4_FC_TAG_UNLINK;
 
-	ret = ext4_fc_track_template(inode, __track_dentry_update,
+	ret = ext4_fc_track_template(handle, inode, __track_dentry_update,
 					(void *)&args, 0);
 	trace_ext4_fc_track_unlink(inode, dentry, ret);
 }
 
-void ext4_fc_track_link(struct inode *inode, struct dentry *dentry)
+void ext4_fc_track_unlink(handle_t *handle, struct dentry *dentry)
+{
+	__ext4_fc_track_unlink(handle, d_inode(dentry), dentry);
+}
+
+void __ext4_fc_track_link(handle_t *handle,
+	struct inode *inode, struct dentry *dentry)
 {
 	struct __track_dentry_update_args args;
 	int ret;
@@ -443,20 +449,26 @@ void ext4_fc_track_link(struct inode *inode, struct dentry *dentry)
 	args.dentry = dentry;
 	args.op = EXT4_FC_TAG_LINK;
 
-	ret = ext4_fc_track_template(inode, __track_dentry_update,
+	ret = ext4_fc_track_template(handle, inode, __track_dentry_update,
 					(void *)&args, 0);
 	trace_ext4_fc_track_link(inode, dentry, ret);
 }
 
-void ext4_fc_track_create(struct inode *inode, struct dentry *dentry)
+void ext4_fc_track_link(handle_t *handle, struct dentry *dentry)
+{
+	__ext4_fc_track_link(handle, d_inode(dentry), dentry);
+}
+
+void ext4_fc_track_create(handle_t *handle, struct dentry *dentry)
 {
 	struct __track_dentry_update_args args;
+	struct inode *inode = d_inode(dentry);
 	int ret;
 
 	args.dentry = dentry;
 	args.op = EXT4_FC_TAG_CREAT;
 
-	ret = ext4_fc_track_template(inode, __track_dentry_update,
+	ret = ext4_fc_track_template(handle, inode, __track_dentry_update,
 					(void *)&args, 0);
 	trace_ext4_fc_track_create(inode, dentry, ret);
 }
@@ -472,14 +484,14 @@ static int __track_inode(struct inode *inode, void *arg, bool update)
 	return 0;
 }
 
-void ext4_fc_track_inode(struct inode *inode)
+void ext4_fc_track_inode(handle_t *handle, struct inode *inode)
 {
 	int ret;
 
 	if (S_ISDIR(inode->i_mode))
 		return;
 
-	ret = ext4_fc_track_template(inode, __track_inode, NULL, 1);
+	ret = ext4_fc_track_template(handle, inode, __track_inode, NULL, 1);
 	trace_ext4_fc_track_inode(inode, ret);
 }
 
@@ -515,7 +527,7 @@ static int __track_range(struct inode *inode, void *arg, bool update)
 	return 0;
 }
 
-void ext4_fc_track_range(struct inode *inode, ext4_lblk_t start,
+void ext4_fc_track_range(handle_t *handle, struct inode *inode, ext4_lblk_t start,
 			 ext4_lblk_t end)
 {
 	struct __track_range_args args;
@@ -527,7 +539,7 @@ void ext4_fc_track_range(struct inode *inode, ext4_lblk_t start,
 	args.start = start;
 	args.end = end;
 
-	ret = ext4_fc_track_template(inode,  __track_range, &args, 1);
+	ret = ext4_fc_track_template(handle, inode,  __track_range, &args, 1);
 
 	trace_ext4_fc_track_range(inode, start, end, ret);
 }
@@ -1263,7 +1275,7 @@ static int ext4_fc_replay_unlink(struct super_block *sb, struct ext4_fc_tl *tl)
 		return 0;
 	}
 
-	ret = __ext4_unlink(old_parent, &entry, inode);
+	ret = __ext4_unlink(NULL, old_parent, &entry, inode);
 	/* -ENOENT ok coz it might not exist anymore. */
 	if (ret == -ENOENT)
 		ret = 0;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 081b6a86b5db..87120c4c44f3 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -732,7 +732,7 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
 			if (ret)
 				return ret;
 		}
-		ext4_fc_track_range(inode, map->m_lblk,
+		ext4_fc_track_range(handle, inode, map->m_lblk,
 			    map->m_lblk + map->m_len - 1);
 	}
 
@@ -4111,7 +4111,7 @@ int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length)
 
 		up_write(&EXT4_I(inode)->i_data_sem);
 	}
-	ext4_fc_track_range(inode, first_block, stop_block);
+	ext4_fc_track_range(handle, inode, first_block, stop_block);
 	if (IS_SYNC(inode))
 		ext4_handle_sync(handle);
 
@@ -5444,14 +5444,14 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 			}
 
 			if (shrink)
-				ext4_fc_track_range(inode,
+				ext4_fc_track_range(handle, inode,
 					(attr->ia_size > 0 ? attr->ia_size - 1 : 0) >>
 					inode->i_sb->s_blocksize_bits,
 					(oldsize > 0 ? oldsize - 1 : 0) >>
 					inode->i_sb->s_blocksize_bits);
 			else
 				ext4_fc_track_range(
-					inode,
+					handle, inode,
 					(oldsize > 0 ? oldsize - 1 : oldsize) >>
 					inode->i_sb->s_blocksize_bits,
 					(attr->ia_size > 0 ? attr->ia_size - 1 : 0) >>
@@ -5701,7 +5701,7 @@ int ext4_mark_iloc_dirty(handle_t *handle,
 		put_bh(iloc->bh);
 		return -EIO;
 	}
-	ext4_fc_track_inode(inode);
+	ext4_fc_track_inode(handle, inode);
 
 	if (IS_I_VERSION(inode))
 		inode_inc_iversion(inode);
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 5159830dacb8..b0d4371b684b 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2610,7 +2610,7 @@ static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 		       bool excl)
 {
 	handle_t *handle;
-	struct inode *inode, *inode_save;
+	struct inode *inode;
 	int err, credits, retries = 0;
 
 	err = dquot_initialize(dir);
@@ -2628,11 +2628,9 @@ static int ext4_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 		inode->i_op = &ext4_file_inode_operations;
 		inode->i_fop = &ext4_file_operations;
 		ext4_set_aops(inode);
-		inode_save = inode;
-		ihold(inode_save);
 		err = ext4_add_nondir(handle, dentry, &inode);
-		ext4_fc_track_create(inode_save, dentry);
-		iput(inode_save);
+		if (!err)
+			ext4_fc_track_create(handle, dentry);
 	}
 	if (handle)
 		ext4_journal_stop(handle);
@@ -2647,7 +2645,7 @@ static int ext4_mknod(struct inode *dir, struct dentry *dentry,
 		      umode_t mode, dev_t rdev)
 {
 	handle_t *handle;
-	struct inode *inode, *inode_save;
+	struct inode *inode;
 	int err, credits, retries = 0;
 
 	err = dquot_initialize(dir);
@@ -2664,12 +2662,9 @@ static int ext4_mknod(struct inode *dir, struct dentry *dentry,
 	if (!IS_ERR(inode)) {
 		init_special_inode(inode, inode->i_mode, rdev);
 		inode->i_op = &ext4_special_inode_operations;
-		inode_save = inode;
-		ihold(inode_save);
 		err = ext4_add_nondir(handle, dentry, &inode);
 		if (!err)
-			ext4_fc_track_create(inode_save, dentry);
-		iput(inode_save);
+			ext4_fc_track_create(handle, dentry);
 	}
 	if (handle)
 		ext4_journal_stop(handle);
@@ -2833,7 +2828,6 @@ static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 		iput(inode);
 		goto out_retry;
 	}
-	ext4_fc_track_create(inode, dentry);
 	ext4_inc_count(dir);
 
 	ext4_update_dx_flag(dir);
@@ -2841,6 +2835,7 @@ static int ext4_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 	if (err)
 		goto out_clear_inode;
 	d_instantiate_new(dentry, inode);
+	ext4_fc_track_create(handle, dentry);
 	if (IS_DIRSYNC(dir))
 		ext4_handle_sync(handle);
 
@@ -3175,7 +3170,7 @@ static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
 		goto end_rmdir;
 	ext4_dec_count(dir);
 	ext4_update_dx_flag(dir);
-	ext4_fc_track_unlink(inode, dentry);
+	ext4_fc_track_unlink(handle, dentry);
 	retval = ext4_mark_inode_dirty(handle, dir);
 
 #ifdef CONFIG_UNICODE
@@ -3196,13 +3191,12 @@ static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
 	return retval;
 }
 
-int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
+int __ext4_unlink(handle_t *handle, struct inode *dir, const struct qstr *d_name,
 		  struct inode *inode)
 {
 	int retval = -ENOENT;
 	struct buffer_head *bh;
 	struct ext4_dir_entry_2 *de;
-	handle_t *handle = NULL;
 	int skip_remove_dentry = 0;
 
 	bh = ext4_find_entry(dir, d_name, &de, NULL);
@@ -3221,14 +3215,7 @@ int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
 		if (EXT4_SB(inode->i_sb)->s_mount_state & EXT4_FC_REPLAY)
 			skip_remove_dentry = 1;
 		else
-			goto out_bh;
-	}
-
-	handle = ext4_journal_start(dir, EXT4_HT_DIR,
-				    EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
-	if (IS_ERR(handle)) {
-		retval = PTR_ERR(handle);
-		goto out_bh;
+			goto out;
 	}
 
 	if (IS_DIRSYNC(dir))
@@ -3237,12 +3224,12 @@ int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
 	if (!skip_remove_dentry) {
 		retval = ext4_delete_entry(handle, dir, de, bh);
 		if (retval)
-			goto out_handle;
+			goto out;
 		dir->i_ctime = dir->i_mtime = current_time(dir);
 		ext4_update_dx_flag(dir);
 		retval = ext4_mark_inode_dirty(handle, dir);
 		if (retval)
-			goto out_handle;
+			goto out;
 	} else {
 		retval = 0;
 	}
@@ -3256,15 +3243,14 @@ int __ext4_unlink(struct inode *dir, const struct qstr *d_name,
 	inode->i_ctime = current_time(inode);
 	retval = ext4_mark_inode_dirty(handle, inode);
 
-out_handle:
-	ext4_journal_stop(handle);
-out_bh:
+out:
 	brelse(bh);
 	return retval;
 }
 
 static int ext4_unlink(struct inode *dir, struct dentry *dentry)
 {
+	handle_t *handle;
 	int retval;
 
 	if (unlikely(ext4_forced_shutdown(EXT4_SB(dir->i_sb))))
@@ -3282,9 +3268,16 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
 	if (retval)
 		goto out_trace;
 
-	retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry));
+	handle = ext4_journal_start(dir, EXT4_HT_DIR,
+				    EXT4_DATA_TRANS_BLOCKS(dir->i_sb));
+	if (IS_ERR(handle)) {
+		retval = PTR_ERR(handle);
+		goto out_trace;
+	}
+
+	retval = __ext4_unlink(handle, dir, &dentry->d_name, d_inode(dentry));
 	if (!retval)
-		ext4_fc_track_unlink(d_inode(dentry), dentry);
+		ext4_fc_track_unlink(handle, dentry);
 #ifdef CONFIG_UNICODE
 	/* VFS negative dentries are incompatible with Encoding and
 	 * Case-insensitiveness. Eventually we'll want avoid
@@ -3295,6 +3288,8 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
 	if (IS_CASEFOLDED(dir))
 		d_invalidate(dentry);
 #endif
+	if (handle)
+		ext4_journal_stop(handle);
 
 out_trace:
 	trace_ext4_unlink_exit(dentry, retval);
@@ -3451,7 +3446,6 @@ int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry)
 
 	err = ext4_add_entry(handle, dentry, inode);
 	if (!err) {
-		ext4_fc_track_link(inode, dentry);
 		err = ext4_mark_inode_dirty(handle, inode);
 		/* this can happen only for tmpfile being
 		 * linked the first time
@@ -3459,6 +3453,7 @@ int __ext4_link(struct inode *dir, struct inode *inode, struct dentry *dentry)
 		if (inode->i_nlink == 1)
 			ext4_orphan_del(handle, inode);
 		d_instantiate(dentry, inode);
+		ext4_fc_track_link(handle, dentry);
 	} else {
 		drop_nlink(inode);
 		iput(inode);
@@ -3919,9 +3914,9 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
 			EXT4_FC_REASON_RENAME_DIR);
 	} else {
 		if (new.inode)
-			ext4_fc_track_unlink(new.inode, new.dentry);
-		ext4_fc_track_link(old.inode, new.dentry);
-		ext4_fc_track_unlink(old.inode, old.dentry);
+			ext4_fc_track_unlink(handle, new.dentry);
+		__ext4_fc_track_link(handle, old.inode, new.dentry);
+		__ext4_fc_track_unlink(handle, old.inode, old.dentry);
 	}
 
 	if (new.inode) {
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 05/22] jbd2: rename j_maxlen to j_total_len and add jbd2_journal_max_txn_bufs

[Harshad Shirwadkar]

The on-disk superblock field sb->s_maxlen represents the total size of
the journal including the fast commit area and is no more the max
number of blocks available for a transaction. The maximum number of
blocks available to a transaction is reduced by the number of fast
commit blocks. So, this patch renames j_maxlen to j_total_len to
better represent its intent. Also, it adds a function to calculate max
number of bufs available for a transaction.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/fsmap.c      |  2 +-
 fs/ext4/super.c      |  2 +-
 fs/jbd2/commit.c     |  2 +-
 fs/jbd2/journal.c    | 12 ++++++------
 fs/jbd2/recovery.c   |  6 +++---
 fs/ocfs2/journal.c   |  2 +-
 include/linux/jbd2.h |  9 +++++++--
 7 files changed, 20 insertions(+), 15 deletions(-)

diff --git a/fs/ext4/fsmap.c b/fs/ext4/fsmap.c
index b232c2767534..4c2a9fe30067 100644
--- a/fs/ext4/fsmap.c
+++ b/fs/ext4/fsmap.c
@@ -280,7 +280,7 @@ static int ext4_getfsmap_logdev(struct super_block *sb, struct ext4_fsmap *keys,
 
 	/* Fabricate an rmap entry for the external log device. */
 	irec.fmr_physical = journal->j_blk_offset;
-	irec.fmr_length = journal->j_maxlen;
+	irec.fmr_length = journal->j_total_len;
 	irec.fmr_owner = EXT4_FMR_OWN_LOG;
 	irec.fmr_flags = 0;
 
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 804f9fc5bdbd..49982c230401 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3976,7 +3976,7 @@ int ext4_calculate_overhead(struct super_block *sb)
 	 * loaded or not
 	 */
 	if (sbi->s_journal && !sbi->s_journal_bdev)
-		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen);
+		overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_total_len);
 	else if (ext4_has_feature_journal(sb) && !sbi->s_journal && j_inum) {
 		/* j_inum for internal journal is non-zero */
 		j_inode = ext4_get_journal_inode(sb, j_inum);
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index fa688e163a80..ec516490cb35 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -801,7 +801,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 		if (first_block < journal->j_tail)
 			freed += journal->j_last - journal->j_first;
 		/* Update tail only if we free significant amount of space */
-		if (freed < journal->j_maxlen / 4)
+		if (freed < jbd2_journal_get_max_txn_bufs(journal))
 			update_tail = 0;
 	}
 	J_ASSERT(commit_transaction->t_state == T_COMMIT);
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 0c7c42bd530f..c3c768248527 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1348,7 +1348,7 @@ static journal_t *journal_init_common(struct block_device *bdev,
 	journal->j_dev = bdev;
 	journal->j_fs_dev = fs_dev;
 	journal->j_blk_offset = start;
-	journal->j_maxlen = len;
+	journal->j_total_len = len;
 	/* We need enough buffers to write out full descriptor block. */
 	n = journal->j_blocksize / jbd2_min_tag_size();
 	journal->j_wbufsize = n;
@@ -1531,7 +1531,7 @@ static int journal_reset(journal_t *journal)
 	journal->j_commit_sequence = journal->j_transaction_sequence - 1;
 	journal->j_commit_request = journal->j_commit_sequence;
 
-	journal->j_max_transaction_buffers = journal->j_maxlen / 4;
+	journal->j_max_transaction_buffers = jbd2_journal_get_max_txn_bufs(journal);
 
 	/*
 	 * As a special case, if the on-disk copy is already marked as needing
@@ -1792,15 +1792,15 @@ static int journal_get_superblock(journal_t *journal)
 		goto out;
 	}
 
-	if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen)
-		journal->j_maxlen = be32_to_cpu(sb->s_maxlen);
-	else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) {
+	if (be32_to_cpu(sb->s_maxlen) < journal->j_total_len)
+		journal->j_total_len = be32_to_cpu(sb->s_maxlen);
+	else if (be32_to_cpu(sb->s_maxlen) > journal->j_total_len) {
 		printk(KERN_WARNING "JBD2: journal file too short\n");
 		goto out;
 	}
 
 	if (be32_to_cpu(sb->s_first) == 0 ||
-	    be32_to_cpu(sb->s_first) >= journal->j_maxlen) {
+	    be32_to_cpu(sb->s_first) >= journal->j_total_len) {
 		printk(KERN_WARNING
 			"JBD2: Invalid start block of journal: %u\n",
 			be32_to_cpu(sb->s_first));
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index eb2606133cd8..dc0694fcfcd1 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -74,8 +74,8 @@ static int do_readahead(journal_t *journal, unsigned int start)
 
 	/* Do up to 128K of readahead */
 	max = start + (128 * 1024 / journal->j_blocksize);
-	if (max > journal->j_maxlen)
-		max = journal->j_maxlen;
+	if (max > journal->j_total_len)
+		max = journal->j_total_len;
 
 	/* Do the readahead itself.  We'll submit MAXBUF buffer_heads at
 	 * a time to the block device IO layer. */
@@ -134,7 +134,7 @@ static int jread(struct buffer_head **bhp, journal_t *journal,
 
 	*bhp = NULL;
 
-	if (offset >= journal->j_maxlen) {
+	if (offset >= journal->j_total_len) {
 		printk(KERN_ERR "JBD2: corrupted journal superblock\n");
 		return -EFSCORRUPTED;
 	}
diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index b9a9d69dde7e..db52e843002a 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -877,7 +877,7 @@ int ocfs2_journal_init(struct ocfs2_journal *journal, int *dirty)
 		goto done;
 	}
 
-	trace_ocfs2_journal_init_maxlen(j_journal->j_maxlen);
+	trace_ocfs2_journal_init_maxlen(j_journal->j_total_len);
 
 	*dirty = (le32_to_cpu(di->id1.journal1.ij_flags) &
 		  OCFS2_JOURNAL_DIRTY_FL);
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 1d5566af48ac..e0b6b53eae64 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -988,9 +988,9 @@ struct journal_s
 	struct block_device	*j_fs_dev;
 
 	/**
-	 * @j_maxlen: Total maximum capacity of the journal region on disk.
+	 * @j_total_len: Total maximum capacity of the journal region on disk.
 	 */
-	unsigned int		j_maxlen;
+	unsigned int		j_total_len;
 
 	/**
 	 * @j_reserved_credits:
@@ -1624,6 +1624,11 @@ int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode);
 int jbd2_fc_wait_bufs(journal_t *journal, int num_blks);
 int jbd2_fc_release_bufs(journal_t *journal);
 
+static inline int jbd2_journal_get_max_txn_bufs(journal_t *journal)
+{
+	return (journal->j_total_len - journal->j_fc_wbufsize) / 4;
+}
+
 /*
  * is_journal_abort
  *
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 06/22] ext4: clean up the JBD2 API that initializes fast commits

[Harshad Shirwadkar]

This patch removes jbd2_fc_init() API and its related functions to
simplify enabling fast commits. With this change, the number of fast
commit blocks to use is solely determined by the JBD2 layer. So, we
move the default value for minimum number of fast commit blocks from
ext4/fast_commit.h to include/linux/jbd2.h. However, whether or not to
use fast commits is determined by the file system. The file system
just sets the fast commit feature using
jbd2_journal_set_features(). JBD2 layer then determines how many
blocks to use for fast commits (based on the value found in the JBD2
superblock).

Note that the JBD2 feature flag of fast commits is just an indication
that there are fast commit blocks present on disk. It doesn't tell
JBD2 layer about the intent of the file system of whether to it wants
to use fast commit or not. That's why, we blindly clear the fast
commit flag in journal_reset() after the recovery is done.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/fast_commit.c | 14 -------
 fs/ext4/fast_commit.h |  3 --
 fs/ext4/super.c       |  8 ++++
 fs/jbd2/journal.c     | 96 +++++++++++++++++++++++++------------------
 include/linux/jbd2.h  |  2 +-
 5 files changed, 65 insertions(+), 58 deletions(-)

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 9399e9cccb7e..bab60c5d5095 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -2091,8 +2091,6 @@ static int ext4_fc_replay(journal_t *journal, struct buffer_head *bh,
 
 void ext4_fc_init(struct super_block *sb, journal_t *journal)
 {
-	int num_fc_blocks;
-
 	/*
 	 * We set replay callback even if fast commit disabled because we may
 	 * could still have fast commit blocks that need to be replayed even if
@@ -2102,18 +2100,6 @@ void ext4_fc_init(struct super_block *sb, journal_t *journal)
 	if (!test_opt2(sb, JOURNAL_FAST_COMMIT))
 		return;
 	journal->j_fc_cleanup_callback = ext4_fc_cleanup;
-	if (!buffer_uptodate(journal->j_sb_buffer)
-		&& ext4_read_bh_lock(journal->j_sb_buffer, REQ_META | REQ_PRIO,
-					true)) {
-		ext4_msg(sb, KERN_ERR, "I/O error on journal");
-		return;
-	}
-	num_fc_blocks = be32_to_cpu(journal->j_superblock->s_num_fc_blks);
-	if (jbd2_fc_init(journal, num_fc_blocks ? num_fc_blocks :
-					EXT4_NUM_FC_BLKS)) {
-		pr_warn("Error while enabling fast commits, turning off.");
-		ext4_clear_feature_fast_commit(sb);
-	}
 }
 
 const char *fc_ineligible_reasons[] = {
diff --git a/fs/ext4/fast_commit.h b/fs/ext4/fast_commit.h
index 140fbb6af19e..1d96e0ac8138 100644
--- a/fs/ext4/fast_commit.h
+++ b/fs/ext4/fast_commit.h
@@ -3,9 +3,6 @@
 #ifndef __FAST_COMMIT_H__
 #define __FAST_COMMIT_H__
 
-/* Number of blocks in journal area to allocate for fast commits */
-#define EXT4_NUM_FC_BLKS		256
-
 /* Fast commit tags */
 #define EXT4_FC_TAG_ADD_RANGE		0x0001
 #define EXT4_FC_TAG_DEL_RANGE		0x0002
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 49982c230401..9d2fbeb0c9ea 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4857,6 +4857,14 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		goto failed_mount_wq;
 	}
 
+	if (test_opt2(sb, JOURNAL_FAST_COMMIT) &&
+		!jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
+					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT)) {
+		ext4_msg(sb, KERN_ERR,
+			"Failed to set fast commit journal feature");
+		goto failed_mount_wq;
+	}
+
 	/* We have now updated the journal if required, so we can
 	 * validate the data journaling mode. */
 	switch (test_opt(sb, DATA_FLAGS)) {
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index c3c768248527..500152f0421a 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1352,19 +1352,12 @@ static journal_t *journal_init_common(struct block_device *bdev,
 	/* We need enough buffers to write out full descriptor block. */
 	n = journal->j_blocksize / jbd2_min_tag_size();
 	journal->j_wbufsize = n;
+	journal->j_fc_wbuf = NULL;
 	journal->j_wbuf = kmalloc_array(n, sizeof(struct buffer_head *),
 					GFP_KERNEL);
 	if (!journal->j_wbuf)
 		goto err_cleanup;
 
-	if (journal->j_fc_wbufsize > 0) {
-		journal->j_fc_wbuf = kmalloc_array(journal->j_fc_wbufsize,
-					sizeof(struct buffer_head *),
-					GFP_KERNEL);
-		if (!journal->j_fc_wbuf)
-			goto err_cleanup;
-	}
-
 	bh = getblk_unmovable(journal->j_dev, start, journal->j_blocksize);
 	if (!bh) {
 		pr_err("%s: Cannot get buffer for journal superblock\n",
@@ -1378,23 +1371,11 @@ static journal_t *journal_init_common(struct block_device *bdev,
 
 err_cleanup:
 	kfree(journal->j_wbuf);
-	kfree(journal->j_fc_wbuf);
 	jbd2_journal_destroy_revoke(journal);
 	kfree(journal);
 	return NULL;
 }
 
-int jbd2_fc_init(journal_t *journal, int num_fc_blks)
-{
-	journal->j_fc_wbufsize = num_fc_blks;
-	journal->j_fc_wbuf = kmalloc_array(journal->j_fc_wbufsize,
-				sizeof(struct buffer_head *), GFP_KERNEL);
-	if (!journal->j_fc_wbuf)
-		return -ENOMEM;
-	return 0;
-}
-EXPORT_SYMBOL(jbd2_fc_init);
-
 /* jbd2_journal_init_dev and jbd2_journal_init_inode:
  *
  * Create a journal structure assigned some fixed set of disk blocks to
@@ -1512,16 +1493,7 @@ static int journal_reset(journal_t *journal)
 	}
 
 	journal->j_first = first;
-
-	if (jbd2_has_feature_fast_commit(journal) &&
-	    journal->j_fc_wbufsize > 0) {
-		journal->j_fc_last = last;
-		journal->j_last = last - journal->j_fc_wbufsize;
-		journal->j_fc_first = journal->j_last + 1;
-		journal->j_fc_off = 0;
-	} else {
-		journal->j_last = last;
-	}
+	journal->j_last = last;
 
 	journal->j_head = journal->j_first;
 	journal->j_tail = journal->j_first;
@@ -1533,6 +1505,13 @@ static int journal_reset(journal_t *journal)
 
 	journal->j_max_transaction_buffers = jbd2_journal_get_max_txn_bufs(journal);
 
+	/*
+	 * Now that journal recovery is done, turn fast commits off here. This
+	 * way, if fast commit was enabled before the crash but if now FS has
+	 * disabled it, we don't enable fast commits.
+	 */
+	jbd2_clear_feature_fast_commit(journal);
+
 	/*
 	 * As a special case, if the on-disk copy is already marked as needing
 	 * no recovery (s_start == 0), then we can safely defer the superblock
@@ -1872,6 +1851,7 @@ static int load_superblock(journal_t *journal)
 {
 	int err;
 	journal_superblock_t *sb;
+	int num_fc_blocks;
 
 	err = journal_get_superblock(journal);
 	if (err)
@@ -1883,15 +1863,17 @@ static int load_superblock(journal_t *journal)
 	journal->j_tail = be32_to_cpu(sb->s_start);
 	journal->j_first = be32_to_cpu(sb->s_first);
 	journal->j_errno = be32_to_cpu(sb->s_errno);
+	journal->j_last = be32_to_cpu(sb->s_maxlen);
 
-	if (jbd2_has_feature_fast_commit(journal) &&
-	    journal->j_fc_wbufsize > 0) {
+	if (jbd2_has_feature_fast_commit(journal)) {
 		journal->j_fc_last = be32_to_cpu(sb->s_maxlen);
-		journal->j_last = journal->j_fc_last - journal->j_fc_wbufsize;
+		num_fc_blocks = be32_to_cpu(sb->s_num_fc_blks);
+		if (!num_fc_blocks)
+			num_fc_blocks = JBD2_MIN_FC_BLOCKS;
+		if (journal->j_last - num_fc_blocks >= JBD2_MIN_JOURNAL_BLOCKS)
+			journal->j_last = journal->j_fc_last - num_fc_blocks;
 		journal->j_fc_first = journal->j_last + 1;
 		journal->j_fc_off = 0;
-	} else {
-		journal->j_last = be32_to_cpu(sb->s_maxlen);
 	}
 
 	return 0;
@@ -1954,9 +1936,6 @@ int jbd2_journal_load(journal_t *journal)
 	 */
 	journal->j_flags &= ~JBD2_ABORT;
 
-	if (journal->j_fc_wbufsize > 0)
-		jbd2_journal_set_features(journal, 0, 0,
-					  JBD2_FEATURE_INCOMPAT_FAST_COMMIT);
 	/* OK, we've finished with the dynamic journal bits:
 	 * reinitialise the dynamic contents of the superblock in memory
 	 * and reset them on disk. */
@@ -2040,8 +2019,7 @@ int jbd2_journal_destroy(journal_t *journal)
 		jbd2_journal_destroy_revoke(journal);
 	if (journal->j_chksum_driver)
 		crypto_free_shash(journal->j_chksum_driver);
-	if (journal->j_fc_wbufsize > 0)
-		kfree(journal->j_fc_wbuf);
+	kfree(journal->j_fc_wbuf);
 	kfree(journal->j_wbuf);
 	kfree(journal);
 
@@ -2116,6 +2094,37 @@ int jbd2_journal_check_available_features(journal_t *journal, unsigned long comp
 	return 0;
 }
 
+static int
+jbd2_journal_initialize_fast_commit(journal_t *journal)
+{
+	journal_superblock_t *sb = journal->j_superblock;
+	unsigned long long num_fc_blks;
+
+	num_fc_blks = be32_to_cpu(sb->s_num_fc_blks);
+	if (num_fc_blks == 0)
+		num_fc_blks = JBD2_MIN_FC_BLOCKS;
+	if (journal->j_last - num_fc_blks < JBD2_MIN_JOURNAL_BLOCKS)
+		return -ENOSPC;
+
+	/* Are we called twice? */
+	WARN_ON(journal->j_fc_wbuf != NULL);
+	journal->j_fc_wbuf = kmalloc_array(num_fc_blks,
+				sizeof(struct buffer_head *), GFP_KERNEL);
+	if (!journal->j_fc_wbuf)
+		return -ENOMEM;
+
+	journal->j_fc_wbufsize = num_fc_blks;
+	journal->j_fc_last = journal->j_last;
+	journal->j_last = journal->j_fc_last - num_fc_blks;
+	journal->j_fc_first = journal->j_last + 1;
+	journal->j_fc_off = 0;
+	journal->j_free = journal->j_last - journal->j_first;
+	journal->j_max_transaction_buffers =
+		jbd2_journal_get_max_txn_bufs(journal);
+
+	return 0;
+}
+
 /**
  * int jbd2_journal_set_features() - Mark a given journal feature in the superblock
  * @journal: Journal to act on.
@@ -2159,6 +2168,13 @@ int jbd2_journal_set_features(journal_t *journal, unsigned long compat,
 
 	sb = journal->j_superblock;
 
+	if (incompat & JBD2_FEATURE_INCOMPAT_FAST_COMMIT) {
+		if (jbd2_journal_initialize_fast_commit(journal)) {
+			pr_err("JBD2: Cannot enable fast commits.\n");
+			return 0;
+		}
+	}
+
 	/* Load the checksum driver if necessary */
 	if ((journal->j_chksum_driver == NULL) &&
 	    INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) {
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index e0b6b53eae64..b2caf7bbd8e5 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -68,6 +68,7 @@ extern void *jbd2_alloc(size_t size, gfp_t flags);
 extern void jbd2_free(void *ptr, size_t size);
 
 #define JBD2_MIN_JOURNAL_BLOCKS 1024
+#define JBD2_MIN_FC_BLOCKS	256
 
 #ifdef __KERNEL__
 
@@ -1614,7 +1615,6 @@ extern void __jbd2_journal_drop_transaction(journal_t *, transaction_t *);
 extern int jbd2_cleanup_journal_tail(journal_t *);
 
 /* Fast commit related APIs */
-int jbd2_fc_init(journal_t *journal, int num_fc_blks);
 int jbd2_fc_begin_commit(journal_t *journal, tid_t tid);
 int jbd2_fc_end_commit(journal_t *journal);
 int jbd2_fc_end_commit_fallback(journal_t *journal, tid_t tid);
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 07/22] jbd2: drop jbd2_fc_init documentation

[Harshad Shirwadkar]

Now that jbd2_fc_init is dropped, drop its docs too.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 Documentation/filesystems/journalling.rst | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/Documentation/filesystems/journalling.rst b/Documentation/filesystems/journalling.rst
index 5a5f70b4063e..e18f90ffc6fd 100644
--- a/Documentation/filesystems/journalling.rst
+++ b/Documentation/filesystems/journalling.rst
@@ -136,10 +136,8 @@ Fast commits
 ~~~~~~~~~~~~
 
 JBD2 to also allows you to perform file-system specific delta commits known as
-fast commits. In order to use fast commits, you first need to call
-:c:func:`jbd2_fc_init` and tell how many blocks at the end of journal
-area should be reserved for fast commits. Along with that, you will also need
-to set following callbacks that perform correspodning work:
+fast commits. In order to use fast commits, you will need to set following
+callbacks that perform correspodning work:
 
 `journal->j_fc_cleanup_cb`: Cleanup function called after every full commit and
 fast commit.
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 08/22] jbd2: don't use state lock during commit path

[Harshad Shirwadkar]

Variables journal->j_fc_off, journal->j_fc_wbuf are accessed during
commit path. Since today we allow only one process to perform a fast
commit, there is no need take state lock before accessing these
variables. This patch removes these locks and adds comments to
describe this.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/jbd2/journal.c    |  6 ------
 include/linux/jbd2.h | 10 ++++++----
 2 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 500152f0421a..778ea50fc8d1 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -865,7 +865,6 @@ int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out)
 	int fc_off;
 
 	*bh_out = NULL;
-	write_lock(&journal->j_state_lock);
 
 	if (journal->j_fc_off + journal->j_fc_first < journal->j_fc_last) {
 		fc_off = journal->j_fc_off;
@@ -874,7 +873,6 @@ int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out)
 	} else {
 		ret = -EINVAL;
 	}
-	write_unlock(&journal->j_state_lock);
 
 	if (ret)
 		return ret;
@@ -909,9 +907,7 @@ int jbd2_fc_wait_bufs(journal_t *journal, int num_blks)
 	struct buffer_head *bh;
 	int i, j_fc_off;
 
-	read_lock(&journal->j_state_lock);
 	j_fc_off = journal->j_fc_off;
-	read_unlock(&journal->j_state_lock);
 
 	/*
 	 * Wait in reverse order to minimize chances of us being woken up before
@@ -939,9 +935,7 @@ int jbd2_fc_release_bufs(journal_t *journal)
 	struct buffer_head *bh;
 	int i, j_fc_off;
 
-	read_lock(&journal->j_state_lock);
 	j_fc_off = journal->j_fc_off;
-	read_unlock(&journal->j_state_lock);
 
 	/*
 	 * Wait in reverse order to minimize chances of us being woken up before
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index b2caf7bbd8e5..5f0ef6380b0c 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -945,8 +945,9 @@ struct journal_s
 	/**
 	 * @j_fc_off:
 	 *
-	 * Number of fast commit blocks currently allocated.
-	 * [j_state_lock].
+	 * Number of fast commit blocks currently allocated. Accessed only
+	 * during fast commit. Currently only process can do fast commit, so
+	 * this field is not protected by any lock.
 	 */
 	unsigned long		j_fc_off;
 
@@ -1109,8 +1110,9 @@ struct journal_s
 	struct buffer_head	**j_wbuf;
 
 	/**
-	 * @j_fc_wbuf: Array of fast commit bhs for
-	 * jbd2_journal_commit_transaction.
+	 * @j_fc_wbuf: Array of fast commit bhs for fast commit. Accessed only
+	 * during a fast commit. Currently only process can do fast commit, so
+	 * this field is not protected by any lock.
 	 */
 	struct buffer_head	**j_fc_wbuf;
 
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 09/22] jbd2: don't pass tid to jbd2_fc_end_commit_fallback()

[Harshad Shirwadkar]

In jbd2_fc_end_commit_fallback(), we know which tid to commit. There's
no need for caller to pass it.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/fast_commit.c |  2 +-
 fs/jbd2/journal.c     | 12 +++++++++---
 include/linux/jbd2.h  |  2 +-
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index bab60c5d5095..e69c580fa91e 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -1143,7 +1143,7 @@ int ext4_fc_commit(journal_t *journal, tid_t commit_tid)
 		"Fast commit ended with blks = %d, reason = %d, subtid - %d",
 		nblks, reason, subtid);
 	if (reason == EXT4_FC_REASON_FC_FAILED)
-		return jbd2_fc_end_commit_fallback(journal, commit_tid);
+		return jbd2_fc_end_commit_fallback(journal);
 	if (reason == EXT4_FC_REASON_FC_START_FAILED ||
 		reason == EXT4_FC_REASON_INELIGIBLE)
 		return jbd2_complete_transaction(journal, commit_tid);
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 778ea50fc8d1..59166e299cde 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -777,13 +777,19 @@ static int __jbd2_fc_end_commit(journal_t *journal, tid_t tid, bool fallback)
 
 int jbd2_fc_end_commit(journal_t *journal)
 {
-	return __jbd2_fc_end_commit(journal, 0, 0);
+	return __jbd2_fc_end_commit(journal, 0, false);
 }
 EXPORT_SYMBOL(jbd2_fc_end_commit);
 
-int jbd2_fc_end_commit_fallback(journal_t *journal, tid_t tid)
+int jbd2_fc_end_commit_fallback(journal_t *journal)
 {
-	return __jbd2_fc_end_commit(journal, tid, 1);
+	tid_t tid;
+
+	read_lock(&journal->j_state_lock);
+	tid = journal->j_running_transaction ?
+		journal->j_running_transaction->t_tid : 0;
+	read_unlock(&journal->j_state_lock);
+	return __jbd2_fc_end_commit(journal, tid, true);
 }
 EXPORT_SYMBOL(jbd2_fc_end_commit_fallback);
 
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 5f0ef6380b0c..1c49fd62ff2e 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -1619,7 +1619,7 @@ extern int jbd2_cleanup_journal_tail(journal_t *);
 /* Fast commit related APIs */
 int jbd2_fc_begin_commit(journal_t *journal, tid_t tid);
 int jbd2_fc_end_commit(journal_t *journal);
-int jbd2_fc_end_commit_fallback(journal_t *journal, tid_t tid);
+int jbd2_fc_end_commit_fallback(journal_t *journal);
 int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out);
 int jbd2_submit_inode_data(struct jbd2_inode *jinode);
 int jbd2_wait_inode_data(journal_t *journal, struct jbd2_inode *jinode);
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 10/22] jbd2: add todo for a fast commit performance optimization

[Harshad Shirwadkar]

Fast commit performance can be optimized if commit thread doesn't wait
for ongoing fast commits to complete until the transaction enters
T_FLUSH state. Document this optimization.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/jbd2/commit.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index ec516490cb35..b121d7d434c6 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -450,6 +450,15 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 		schedule();
 		write_lock(&journal->j_state_lock);
 		finish_wait(&journal->j_fc_wait, &wait);
+		/*
+		 * TODO: by blocking fast commits here, we are increasing
+		 * fsync() latency slightly. Strictly speaking, we don't need
+		 * to block fast commits until the transaction enters T_FLUSH
+		 * state. So an optimization is possible where we block new fast
+		 * commits here and wait for existing ones to complete
+		 * just before we enter T_FLUSH. That way, the existing fast
+		 * commits and this full commit can proceed parallely.
+		 */
 	}
 	write_unlock(&journal->j_state_lock);
 
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 11/22] jbd2: don't touch buffer state until it is filled

[Harshad Shirwadkar]

Fast commit buffers should be filled in before toucing their
state. Remove code that sets buffer state as dirty before the buffer
is passed to the file system.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/jbd2/journal.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 59166e299cde..b5fbcd1b444c 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -891,11 +891,7 @@ int jbd2_fc_get_buf(journal_t *journal, struct buffer_head **bh_out)
 	if (!bh)
 		return -ENOMEM;
 
-	lock_buffer(bh);
 
-	clear_buffer_uptodate(bh);
-	set_buffer_dirty(bh);
-	unlock_buffer(bh);
 	journal->j_fc_wbuf[fc_off] = bh;
 
 	*bh_out = bh;
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 12/22] jbd2: don't read journal->j_commit_sequence without taking a lock

[Harshad Shirwadkar]

Take journal state lock before reading journal->j_commit_sequence.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/jbd2/journal.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index b5fbcd1b444c..f7ebf6ef69af 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -734,10 +734,12 @@ int jbd2_fc_begin_commit(journal_t *journal, tid_t tid)
 	if (!journal->j_stats.ts_tid)
 		return -EINVAL;
 
-	if (tid <= journal->j_commit_sequence)
+	write_lock(&journal->j_state_lock);
+	if (tid <= journal->j_commit_sequence) {
+		write_unlock(&journal->j_state_lock);
 		return -EALREADY;
+	}
 
-	write_lock(&journal->j_state_lock);
 	if (journal->j_flags & JBD2_FULL_COMMIT_ONGOING ||
 	    (journal->j_flags & JBD2_FAST_COMMIT_ONGOING)) {
 		DEFINE_WAIT(wait);
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 13/22] ext4: dedpulicate the code to wait on inode that's being committed

[Harshad Shirwadkar]

This patch removes the deduplicates the code that implements waiting
on inode that's being committed. That code is moved into a new
function.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/fast_commit.c | 61 +++++++++++++++++++------------------------
 1 file changed, 27 insertions(+), 34 deletions(-)

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index e69c580fa91e..fc5a5e6a581d 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -155,6 +155,30 @@ void ext4_fc_init_inode(struct inode *inode)
 	ei->i_fc_committed_subtid = 0;
 }
 
+/* This function must be called with sbi->s_fc_lock held. */
+static void ext4_fc_wait_committing_inode(struct inode *inode)
+{
+	wait_queue_head_t *wq;
+	struct ext4_inode_info *ei = EXT4_I(inode);
+
+#if (BITS_PER_LONG < 64)
+	DEFINE_WAIT_BIT(wait, &ei->i_state_flags,
+			EXT4_STATE_FC_COMMITTING);
+	wq = bit_waitqueue(&ei->i_state_flags,
+				EXT4_STATE_FC_COMMITTING);
+#else
+	DEFINE_WAIT_BIT(wait, &ei->i_flags,
+			EXT4_STATE_FC_COMMITTING);
+	wq = bit_waitqueue(&ei->i_flags,
+				EXT4_STATE_FC_COMMITTING);
+#endif
+	lockdep_assert_held(&EXT4_SB(inode->i_sb)->s_fc_lock);
+	prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
+	spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock);
+	schedule();
+	finish_wait(wq, &wait.wq_entry);
+}
+
 /*
  * Inform Ext4's fast about start of an inode update
  *
@@ -176,22 +200,7 @@ void ext4_fc_start_update(struct inode *inode)
 		goto out;
 
 	if (ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING)) {
-		wait_queue_head_t *wq;
-#if (BITS_PER_LONG < 64)
-		DEFINE_WAIT_BIT(wait, &ei->i_state_flags,
-				EXT4_STATE_FC_COMMITTING);
-		wq = bit_waitqueue(&ei->i_state_flags,
-				   EXT4_STATE_FC_COMMITTING);
-#else
-		DEFINE_WAIT_BIT(wait, &ei->i_flags,
-				EXT4_STATE_FC_COMMITTING);
-		wq = bit_waitqueue(&ei->i_flags,
-				   EXT4_STATE_FC_COMMITTING);
-#endif
-		prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
-		spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock);
-		schedule();
-		finish_wait(wq, &wait.wq_entry);
+		ext4_fc_wait_committing_inode(inode);
 		goto restart;
 	}
 out:
@@ -234,26 +243,10 @@ void ext4_fc_del(struct inode *inode)
 	}
 
 	if (ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING)) {
-		wait_queue_head_t *wq;
-#if (BITS_PER_LONG < 64)
-		DEFINE_WAIT_BIT(wait, &ei->i_state_flags,
-				EXT4_STATE_FC_COMMITTING);
-		wq = bit_waitqueue(&ei->i_state_flags,
-				   EXT4_STATE_FC_COMMITTING);
-#else
-		DEFINE_WAIT_BIT(wait, &ei->i_flags,
-				EXT4_STATE_FC_COMMITTING);
-		wq = bit_waitqueue(&ei->i_flags,
-				   EXT4_STATE_FC_COMMITTING);
-#endif
-		prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
-		spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock);
-		schedule();
-		finish_wait(wq, &wait.wq_entry);
+		ext4_fc_wait_committing_inode(inode);
 		goto restart;
 	}
-	if (!list_empty(&ei->i_fc_list))
-		list_del_init(&ei->i_fc_list);
+	list_del_init(&ei->i_fc_list);
 	spin_unlock(&EXT4_SB(inode->i_sb)->s_fc_lock);
 }
 
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 14/22] ext4: fix code documentatioon

[Harshad Shirwadkar]

Add a TODO to remember fixing REQ_FUA | REQ_PREFLUSH for fast commit
buffers. Also, fix a typo in top level comment in fast_commit.c

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/fast_commit.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index fc5a5e6a581d..639b2a308c7b 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -83,7 +83,7 @@
  *
  * Atomicity of commits
  * --------------------
- * In order to gaurantee atomicity during the commit operation, fast commit
+ * In order to guarantee atomicity during the commit operation, fast commit
  * uses "EXT4_FC_TAG_TAIL" tag that marks a fast commit as complete. Tail
  * tag contains CRC of the contents and TID of the transaction after which
  * this fast commit should be applied. Recovery code replays fast commit
@@ -542,6 +542,7 @@ static void ext4_fc_submit_bh(struct super_block *sb)
 	int write_flags = REQ_SYNC;
 	struct buffer_head *bh = EXT4_SB(sb)->s_fc_bh;
 
+	/* TODO: REQ_FUA | REQ_PREFLUSH is unnecessarily expensive. */
 	if (test_opt(sb, BARRIER))
 		write_flags |= REQ_FUA | REQ_PREFLUSH;
 	lock_buffer(bh);
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 15/22] ext4: mark buf dirty before submitting fast commit buffer

[Harshad Shirwadkar]

Mark the fast commit buffer as dirty before submission.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/fast_commit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 639b2a308c7b..05e6e76a7663 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -546,7 +546,7 @@ static void ext4_fc_submit_bh(struct super_block *sb)
 	if (test_opt(sb, BARRIER))
 		write_flags |= REQ_FUA | REQ_PREFLUSH;
 	lock_buffer(bh);
-	clear_buffer_dirty(bh);
+	set_buffer_dirty(bh);
 	set_buffer_uptodate(bh);
 	bh->b_end_io = ext4_end_buffer_io_sync;
 	submit_bh(REQ_OP_WRITE, write_flags, bh);
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 16/22] ext4: remove unnecessary fast commit calls from ext4_file_mmap

[Harshad Shirwadkar]

Remove unnecessary calls to ext4_fc_start_update() and
ext4_fc_stop_update() from ext4_file_mmap().

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/file.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index d85412d12e3a..80ad5ccc0288 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -761,7 +761,6 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
 	if (!daxdev_mapping_supported(vma, dax_dev))
 		return -EOPNOTSUPP;
 
-	ext4_fc_start_update(inode);
 	file_accessed(file);
 	if (IS_DAX(file_inode(file))) {
 		vma->vm_ops = &ext4_dax_vm_ops;
@@ -769,7 +768,6 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
 	} else {
 		vma->vm_ops = &ext4_file_vm_ops;
 	}
-	ext4_fc_stop_update(inode);
 	return 0;
 }
 
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 17/22] ext4: fix inode dirty check in case of fast commits

[Harshad Shirwadkar]

In case of fast commits, determine if the inode is dirty by checking
if the inode is on fast commit list. This also helps us get rid of
ext4_inode_info.i_fc_committed_subtid field.

Reported-by: Andrea Righi <andrea.righi@canonical.com>
Tested-by: Andrea Righi <andrea.righi@canonical.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/ext4.h        | 3 ---
 fs/ext4/fast_commit.c | 3 ---
 fs/ext4/inode.c       | 3 +--
 3 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 23f8edd4fb2a..e81104578015 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1028,9 +1028,6 @@ struct ext4_inode_info {
 					 * protected by sbi->s_fc_lock.
 					 */
 
-	/* Fast commit subtid when this inode was committed */
-	unsigned int i_fc_committed_subtid;
-
 	/* Start of lblk range that needs to be committed in this fast commit */
 	ext4_lblk_t i_fc_lblk_start;
 
diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 05e6e76a7663..6b963e09af2c 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -152,7 +152,6 @@ void ext4_fc_init_inode(struct inode *inode)
 	INIT_LIST_HEAD(&ei->i_fc_list);
 	init_waitqueue_head(&ei->i_fc_wait);
 	atomic_set(&ei->i_fc_updates, 0);
-	ei->i_fc_committed_subtid = 0;
 }
 
 /* This function must be called with sbi->s_fc_lock held. */
@@ -1037,8 +1036,6 @@ static int ext4_fc_perform_commit(journal_t *journal)
 		if (ret)
 			goto out;
 		spin_lock(&sbi->s_fc_lock);
-		EXT4_I(inode)->i_fc_committed_subtid =
-			atomic_read(&sbi->s_fc_subtid);
 	}
 	spin_unlock(&sbi->s_fc_lock);
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 87120c4c44f3..000bf70e88ed 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3312,8 +3312,7 @@ static bool ext4_inode_datasync_dirty(struct inode *inode)
 			EXT4_I(inode)->i_datasync_tid))
 			return false;
 		if (test_opt2(inode->i_sb, JOURNAL_FAST_COMMIT))
-			return atomic_read(&EXT4_SB(inode->i_sb)->s_fc_subtid) <
-				EXT4_I(inode)->i_fc_committed_subtid;
+			return !list_empty(&EXT4_I(inode)->i_fc_list);
 		return true;
 	}
 
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 18/22] ext4: disable fast commit with data journalling

[Harshad Shirwadkar]

Fast commits don't work with data journalling. This patch disables the
fast commit support when data journalling is turned on.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/fast_commit.c       | 7 +++++++
 fs/ext4/fast_commit.h       | 1 +
 fs/ext4/super.c             | 3 ++-
 include/trace/events/ext4.h | 6 ++++--
 4 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 6b963e09af2c..fb9b4e9d82b2 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -483,6 +483,12 @@ void ext4_fc_track_inode(handle_t *handle, struct inode *inode)
 	if (S_ISDIR(inode->i_mode))
 		return;
 
+	if (ext4_should_journal_data(inode)) {
+		ext4_fc_mark_ineligible(inode->i_sb,
+					EXT4_FC_REASON_INODE_JOURNAL_DATA);
+		return;
+	}
+
 	ret = ext4_fc_track_template(handle, inode, __track_inode, NULL, 1);
 	trace_ext4_fc_track_inode(inode, ret);
 }
@@ -2102,6 +2108,7 @@ const char *fc_ineligible_reasons[] = {
 	"Resize",
 	"Dir renamed",
 	"Falloc range op",
+	"Data journalling",
 	"FC Commit Failed"
 };
 
diff --git a/fs/ext4/fast_commit.h b/fs/ext4/fast_commit.h
index 1d96e0ac8138..3a6e5a1fa1b8 100644
--- a/fs/ext4/fast_commit.h
+++ b/fs/ext4/fast_commit.h
@@ -102,6 +102,7 @@ enum {
 	EXT4_FC_REASON_RESIZE,
 	EXT4_FC_REASON_RENAME_DIR,
 	EXT4_FC_REASON_FALLOC_RANGE,
+	EXT4_FC_REASON_INODE_JOURNAL_DATA,
 	EXT4_FC_COMMIT_FAILED,
 	EXT4_FC_REASON_MAX
 };
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 9d2fbeb0c9ea..5386736913d2 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4340,9 +4340,10 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 #endif
 
 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
-		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, and O_DIRECT support!\n");
+		printk_once(KERN_WARNING "EXT4-fs: Warning: mounting with data=journal disables delayed allocation, dioread_nolock, O_DIRECT and fast_commit support!\n");
 		/* can't mount with both data=journal and dioread_nolock. */
 		clear_opt(sb, DIOREAD_NOLOCK);
+		clear_opt2(sb, JOURNAL_FAST_COMMIT);
 		if (test_opt2(sb, EXPLICIT_DELALLOC)) {
 			ext4_msg(sb, KERN_ERR, "can't mount with "
 				 "both data=journal and delalloc");
diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
index 0f899d3b09d3..70ae5497b73a 100644
--- a/include/trace/events/ext4.h
+++ b/include/trace/events/ext4.h
@@ -104,7 +104,8 @@ TRACE_DEFINE_ENUM(ES_REFERENCED_B);
 		{ EXT4_FC_REASON_SWAP_BOOT,	"SWAP_BOOT"},		\
 		{ EXT4_FC_REASON_RESIZE,	"RESIZE"},		\
 		{ EXT4_FC_REASON_RENAME_DIR,	"RENAME_DIR"},		\
-		{ EXT4_FC_REASON_FALLOC_RANGE,	"FALLOC_RANGE"})
+		{ EXT4_FC_REASON_FALLOC_RANGE,	"FALLOC_RANGE"},	\
+		{ EXT4_FC_REASON_INODE_JOURNAL_DATA,	"INODE_JOURNAL_DATA"})
 
 TRACE_EVENT(ext4_other_inode_update_time,
 	TP_PROTO(struct inode *inode, ino_t orig_ino),
@@ -2917,7 +2918,7 @@ TRACE_EVENT(ext4_fc_stats,
 		    ),
 
 	    TP_printk("dev %d:%d fc ineligible reasons:\n"
-		      "%s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d; "
+		      "%s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d, %s:%d; "
 		      "num_commits:%ld, ineligible: %ld, numblks: %ld",
 		      MAJOR(__entry->dev), MINOR(__entry->dev),
 		      FC_REASON_NAME_STAT(EXT4_FC_REASON_XATTR),
@@ -2928,6 +2929,7 @@ TRACE_EVENT(ext4_fc_stats,
 		      FC_REASON_NAME_STAT(EXT4_FC_REASON_RESIZE),
 		      FC_REASON_NAME_STAT(EXT4_FC_REASON_RENAME_DIR),
 		      FC_REASON_NAME_STAT(EXT4_FC_REASON_FALLOC_RANGE),
+		      FC_REASON_NAME_STAT(EXT4_FC_REASON_INODE_JOURNAL_DATA),
 		      __entry->sbi->s_fc_stats.fc_num_commits,
 		      __entry->sbi->s_fc_stats.fc_ineligible_commits,
 		      __entry->sbi->s_fc_stats.fc_numblks)
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 19/22] ext4: issue fsdev cache flush before starting fast commit

[Harshad Shirwadkar]

If the journal dev is different from fsdev, issue a cache flush before
committing fast commit blocks to disk.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
---
 fs/ext4/fast_commit.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index fb9b4e9d82b2..ebe5f423f8f2 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -1007,6 +1007,13 @@ static int ext4_fc_perform_commit(journal_t *journal)
 	if (ret)
 		return ret;
 
+	/*
+	 * If file system device is different from journal device, issue a cache
+	 * flush before we start writing fast commit blocks.
+	 */
+	if (journal->j_fs_dev != journal->j_dev)
+		blkdev_issue_flush(journal->j_fs_dev, GFP_NOFS);
+
 	blk_start_plug(&plug);
 	if (sbi->s_fc_bytes == 0) {
 		/*
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 20/22] ext4: make s_mount_flags modifications atomic

[Harshad Shirwadkar]

Fast commit file system states are recorded in
sbi->s_mount_flags. Fast commit expects these bit manipulations to be
atomic. This patch adds helpers to make those modifications atomic.

Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/ext4.h        | 40 +++++++++++++++++++++++++++++-----------
 fs/ext4/fast_commit.c | 18 +++++++++---------
 fs/ext4/file.c        |  4 ++--
 fs/ext4/fsync.c       |  2 +-
 fs/ext4/inode.c       |  4 ++--
 fs/ext4/mballoc.c     |  4 ++--
 fs/ext4/super.c       | 14 +++++++-------
 7 files changed, 52 insertions(+), 34 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index e81104578015..16de3d62ce2b 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1419,16 +1419,6 @@ struct ext4_super_block {
 
 #ifdef __KERNEL__
 
-/*
- * run-time mount flags
- */
-#define EXT4_MF_MNTDIR_SAMPLED		0x0001
-#define EXT4_MF_FS_ABORTED		0x0002	/* Fatal error detected */
-#define EXT4_MF_FC_INELIGIBLE		0x0004	/* Fast commit ineligible */
-#define EXT4_MF_FC_COMMITTING		0x0008	/* File system underoing a fast
-						 * commit.
-						 */
-
 #ifdef CONFIG_FS_ENCRYPTION
 #define DUMMY_ENCRYPTION_ENABLED(sbi) ((sbi)->s_dummy_enc_policy.policy != NULL)
 #else
@@ -1471,7 +1461,7 @@ struct ext4_sb_info {
 	struct buffer_head * __rcu *s_group_desc;
 	unsigned int s_mount_opt;
 	unsigned int s_mount_opt2;
-	unsigned int s_mount_flags;
+	unsigned long s_mount_flags;
 	unsigned int s_def_mount_opt;
 	ext4_fsblk_t s_sb_block;
 	atomic64_t s_resv_clusters;
@@ -1703,6 +1693,34 @@ static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
 	_v;								   \
 })
 
+/*
+ * run-time mount flags
+ */
+enum {
+	EXT4_MF_MNTDIR_SAMPLED,
+	EXT4_MF_FS_ABORTED,	/* Fatal error detected */
+	EXT4_MF_FC_INELIGIBLE,	/* Fast commit ineligible */
+	EXT4_MF_FC_COMMITTING	/* File system underoing a fast
+				 * commit.
+				 */
+};
+
+static inline void ext4_set_mount_flag(struct super_block *sb, int bit)
+{
+	set_bit(bit, &EXT4_SB(sb)->s_mount_flags);
+}
+
+static inline void ext4_clear_mount_flag(struct super_block *sb, int bit)
+{
+	clear_bit(bit, &EXT4_SB(sb)->s_mount_flags);
+}
+
+static inline int ext4_test_mount_flag(struct super_block *sb, int bit)
+{
+	return test_bit(bit, &EXT4_SB(sb)->s_mount_flags);
+}
+
+
 /*
  * Simulate_fail codes
  */
diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index ebe5f423f8f2..5cd6630ab1b9 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -261,7 +261,7 @@ void ext4_fc_mark_ineligible(struct super_block *sb, int reason)
 	    (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY))
 		return;
 
-	sbi->s_mount_flags |= EXT4_MF_FC_INELIGIBLE;
+	ext4_set_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
 	WARN_ON(reason >= EXT4_FC_REASON_MAX);
 	sbi->s_fc_stats.fc_ineligible_reason_count[reason]++;
 }
@@ -294,14 +294,14 @@ void ext4_fc_stop_ineligible(struct super_block *sb)
 	    (EXT4_SB(sb)->s_mount_state & EXT4_FC_REPLAY))
 		return;
 
-	EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FC_INELIGIBLE;
+	ext4_set_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
 	atomic_dec(&EXT4_SB(sb)->s_fc_ineligible_updates);
 }
 
 static inline int ext4_fc_is_ineligible(struct super_block *sb)
 {
-	return (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FC_INELIGIBLE) ||
-		atomic_read(&EXT4_SB(sb)->s_fc_ineligible_updates);
+	return (ext4_test_mount_flag(sb, EXT4_MF_FC_INELIGIBLE) ||
+		atomic_read(&EXT4_SB(sb)->s_fc_ineligible_updates));
 }
 
 /*
@@ -349,7 +349,7 @@ static int ext4_fc_track_template(
 	spin_lock(&sbi->s_fc_lock);
 	if (list_empty(&EXT4_I(inode)->i_fc_list))
 		list_add_tail(&EXT4_I(inode)->i_fc_list,
-				(sbi->s_mount_flags & EXT4_MF_FC_COMMITTING) ?
+				(ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_COMMITTING)) ?
 				&sbi->s_fc_q[FC_Q_STAGING] :
 				&sbi->s_fc_q[FC_Q_MAIN]);
 	spin_unlock(&sbi->s_fc_lock);
@@ -402,7 +402,7 @@ static int __track_dentry_update(struct inode *inode, void *arg, bool update)
 	node->fcd_name.len = dentry->d_name.len;
 
 	spin_lock(&sbi->s_fc_lock);
-	if (sbi->s_mount_flags & EXT4_MF_FC_COMMITTING)
+	if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FC_COMMITTING))
 		list_add_tail(&node->fcd_list,
 				&sbi->s_fc_dentry_q[FC_Q_STAGING]);
 	else
@@ -857,7 +857,7 @@ static int ext4_fc_submit_inode_data_all(journal_t *journal)
 	int ret = 0;
 
 	spin_lock(&sbi->s_fc_lock);
-	sbi->s_mount_flags |= EXT4_MF_FC_COMMITTING;
+	ext4_set_mount_flag(sb, EXT4_MF_FC_COMMITTING);
 	list_for_each(pos, &sbi->s_fc_q[FC_Q_MAIN]) {
 		ei = list_entry(pos, struct ext4_inode_info, i_fc_list);
 		ext4_set_inode_state(&ei->vfs_inode, EXT4_STATE_FC_COMMITTING);
@@ -1206,8 +1206,8 @@ static void ext4_fc_cleanup(journal_t *journal, int full)
 	list_splice_init(&sbi->s_fc_q[FC_Q_STAGING],
 				&sbi->s_fc_q[FC_Q_STAGING]);
 
-	sbi->s_mount_flags &= ~EXT4_MF_FC_COMMITTING;
-	sbi->s_mount_flags &= ~EXT4_MF_FC_INELIGIBLE;
+	ext4_clear_mount_flag(sb, EXT4_MF_FC_COMMITTING);
+	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
 
 	if (full)
 		sbi->s_fc_bytes = 0;
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 80ad5ccc0288..3ed8c048fb12 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -780,13 +780,13 @@ static int ext4_sample_last_mounted(struct super_block *sb,
 	handle_t *handle;
 	int err;
 
-	if (likely(sbi->s_mount_flags & EXT4_MF_MNTDIR_SAMPLED))
+	if (likely(ext4_test_mount_flag(sb, EXT4_MF_MNTDIR_SAMPLED)))
 		return 0;
 
 	if (sb_rdonly(sb) || !sb_start_intwrite_trylock(sb))
 		return 0;
 
-	sbi->s_mount_flags |= EXT4_MF_MNTDIR_SAMPLED;
+	ext4_set_mount_flag(sb, EXT4_MF_MNTDIR_SAMPLED);
 	/*
 	 * Sample where the filesystem has been mounted and
 	 * store it in the superblock for sysadmin convenience
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index 81a545fd14a3..a42ca95840f2 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -143,7 +143,7 @@ int ext4_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
 	if (sb_rdonly(inode->i_sb)) {
 		/* Make sure that we read updated s_mount_flags value */
 		smp_rmb();
-		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
+		if (ext4_test_mount_flag(inode->i_sb, EXT4_MF_FS_ABORTED))
 			ret = -EROFS;
 		goto out;
 	}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 000bf70e88ed..0d8385aea898 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2442,7 +2442,7 @@ static int mpage_map_and_submit_extent(handle_t *handle,
 			struct super_block *sb = inode->i_sb;
 
 			if (ext4_forced_shutdown(EXT4_SB(sb)) ||
-			    EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
+			    ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
 				goto invalidate_dirty_pages;
 			/*
 			 * Let the uper layers retry transient errors.
@@ -2676,7 +2676,7 @@ static int ext4_writepages(struct address_space *mapping,
 	 * the stack trace.
 	 */
 	if (unlikely(ext4_forced_shutdown(EXT4_SB(mapping->host->i_sb)) ||
-		     sbi->s_mount_flags & EXT4_MF_FS_ABORTED)) {
+		     ext4_test_mount_flag(inode->i_sb, EXT4_MF_FS_ABORTED))) {
 		ret = -EROFS;
 		goto out_writepages;
 	}
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 85abbfb98cbe..f482a17ae764 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4477,7 +4477,7 @@ static inline void ext4_mb_show_pa(struct super_block *sb)
 {
 	ext4_group_t i, ngroups;
 
-	if (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
+	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
 		return;
 
 	ngroups = ext4_get_groups_count(sb);
@@ -4508,7 +4508,7 @@ static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
 {
 	struct super_block *sb = ac->ac_sb;
 
-	if (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
+	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
 		return;
 
 	mb_debug(sb, "Can't allocate:"
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 5386736913d2..edb36581f6cc 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -686,7 +686,7 @@ static void ext4_handle_error(struct super_block *sb)
 	if (!test_opt(sb, ERRORS_CONT)) {
 		journal_t *journal = EXT4_SB(sb)->s_journal;
 
-		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
+		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
 		if (journal)
 			jbd2_journal_abort(journal, -EIO);
 	}
@@ -904,7 +904,7 @@ void __ext4_abort(struct super_block *sb, const char *function,
 	va_end(args);
 
 	if (sb_rdonly(sb) == 0) {
-		EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
+		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
 		if (EXT4_SB(sb)->s_journal)
 			jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 
@@ -2153,7 +2153,7 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
 		ext4_msg(sb, KERN_WARNING, "Ignoring removed %s option", opt);
 		return 1;
 	case Opt_abort:
-		sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
+		ext4_set_mount_flag(sb, EXT4_MF_FS_ABORTED);
 		return 1;
 	case Opt_i_version:
 		sb->s_flags |= SB_I_VERSION;
@@ -4778,8 +4778,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_MAIN]);
 	INIT_LIST_HEAD(&sbi->s_fc_dentry_q[FC_Q_STAGING]);
 	sbi->s_fc_bytes = 0;
-	sbi->s_mount_flags &= ~EXT4_MF_FC_INELIGIBLE;
-	sbi->s_mount_flags &= ~EXT4_MF_FC_COMMITTING;
+	ext4_clear_mount_flag(sb, EXT4_MF_FC_INELIGIBLE);
+	ext4_clear_mount_flag(sb, EXT4_MF_FC_COMMITTING);
 	spin_lock_init(&sbi->s_fc_lock);
 	memset(&sbi->s_fc_stats, 0, sizeof(sbi->s_fc_stats));
 	sbi->s_fc_replay_state.fc_regions = NULL;
@@ -5881,7 +5881,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 		goto restore_opts;
 	}
 
-	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
+	if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED))
 		ext4_abort(sb, EXT4_ERR_ESHUTDOWN, "Abort forced by user");
 
 	sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
@@ -5895,7 +5895,7 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
 	}
 
 	if ((bool)(*flags & SB_RDONLY) != sb_rdonly(sb)) {
-		if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
+		if (ext4_test_mount_flag(sb, EXT4_MF_FS_ABORTED)) {
 			err = -EROFS;
 			goto restore_opts;
 		}
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 21/22] jbd2: don't start fast commit on aborted journal

[Harshad Shirwadkar]

Fast commit should not be started if the journal is aborted.

Signed-off-by: Harshad Shirwadkar<harshadshirwadkar@gmail.com>
---
 fs/jbd2/journal.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index f7ebf6ef69af..0c3d5e3b24b2 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -727,6 +727,8 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
  */
 int jbd2_fc_begin_commit(journal_t *journal, tid_t tid)
 {
+	if (unlikely(is_journal_aborted(journal)))
+		return -EIO;
 	/*
 	 * Fast commits only allowed if at least one full commit has
 	 * been processed.
-- 
2.29.1.341.ge80a0c044ae-goog

[PATCH v2 22/22] ext4: cleanup fast commit mount options

[Harshad Shirwadkar]

Drop no_fc mount option that disable fast commit even if it was
enabled at mkfs time. Move fc_debug_force mount option under ifdef
EXT4_DEBUG to annotate that this is strictly for debugging and testing
purposes and should not be used in production.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
---
 fs/ext4/super.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index edb36581f6cc..4679dbf14555 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1716,11 +1716,10 @@ enum {
 	Opt_dioread_nolock, Opt_dioread_lock,
 	Opt_discard, Opt_nodiscard, Opt_init_itable, Opt_noinit_itable,
 	Opt_max_dir_size_kb, Opt_nojournal_checksum, Opt_nombcache,
-	Opt_prefetch_block_bitmaps, Opt_no_fc,
+	Opt_prefetch_block_bitmaps,
 #ifdef CONFIG_EXT4_DEBUG
-	Opt_fc_debug_max_replay,
+	Opt_fc_debug_max_replay, Opt_fc_debug_force
 #endif
-	Opt_fc_debug_force
 };
 
 static const match_table_t tokens = {
@@ -1807,9 +1806,8 @@ static const match_table_t tokens = {
 	{Opt_init_itable, "init_itable=%u"},
 	{Opt_init_itable, "init_itable"},
 	{Opt_noinit_itable, "noinit_itable"},
-	{Opt_no_fc, "no_fc"},
-	{Opt_fc_debug_force, "fc_debug_force"},
 #ifdef CONFIG_EXT4_DEBUG
+	{Opt_fc_debug_force, "fc_debug_force"},
 	{Opt_fc_debug_max_replay, "fc_debug_max_replay=%u"},
 #endif
 	{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
@@ -2039,11 +2037,9 @@ static const struct mount_opts {
 	{Opt_nombcache, EXT4_MOUNT_NO_MBCACHE, MOPT_SET},
 	{Opt_prefetch_block_bitmaps, EXT4_MOUNT_PREFETCH_BLOCK_BITMAPS,
 	 MOPT_SET},
-	{Opt_no_fc, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
-	 MOPT_CLEAR | MOPT_2 | MOPT_EXT4_ONLY},
+#ifdef CONFIG_EXT4_DEBUG
 	{Opt_fc_debug_force, EXT4_MOUNT2_JOURNAL_FAST_COMMIT,
 	 MOPT_SET | MOPT_2 | MOPT_EXT4_ONLY},
-#ifdef CONFIG_EXT4_DEBUG
 	{Opt_fc_debug_max_replay, 0, MOPT_GTE0},
 #endif
 	{Opt_err, 0, 0}
-- 
2.29.1.341.ge80a0c044ae-goog