Commit aa75f4d3 authored by Harshad Shirwadkar's avatar Harshad Shirwadkar Committed by Theodore Ts'o
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ext4: main fast-commit commit path 



This patch adds main fast commit commit path handlers. The overall
patch can be divided into two inter-related parts:

(A) Metadata updates tracking

    This part consists of helper functions to track changes that need
    to be committed during a commit operation. These updates are
    maintained by Ext4 in different in-memory queues. Following are
    the APIs and their short description that are implemented in this
    patch:

    - ext4_fc_track_link/unlink/creat() - Track unlink. link and creat
      operations
    - ext4_fc_track_range() - Track changed logical block offsets
      inodes
    - ext4_fc_track_inode() - Track inodes
    - ext4_fc_mark_ineligible() - Mark file system fast commit
      ineligible()
    - ext4_fc_start_update() / ext4_fc_stop_update() /
      ext4_fc_start_ineligible() / ext4_fc_stop_ineligible() These
      functions are useful for co-ordinating inode updates with
      commits.

(B) Main commit Path

    This part consists of functions to convert updates tracked in
    in-memory data structures into on-disk commits. Function
    ext4_fc_commit() is the main entry point to commit path.

Reported-by: default avatarkernel test robot <lkp@intel.com>
Signed-off-by: default avatarHarshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201015203802.3597742-6-harshadshirwadkar@gmail.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent ff780b91

fs/ext4/acl.c

+2 −0
Original line number Diff line number Diff line
@@ -242,6 +242,7 @@ retry: 
	handle = ext4_journal_start(inode, EXT4_HT_XATTR, credits);

	if (IS_ERR(handle))

		return PTR_ERR(handle);

	ext4_fc_start_update(inode);



	if ((type == ACL_TYPE_ACCESS) && acl) {

		error = posix_acl_update_mode(inode, &mode, &acl);
@@ -259,6 +260,7 @@ retry: 
	}

out_stop:

	ext4_journal_stop(handle);

	ext4_fc_stop_update(inode);

	if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))

		goto retry;

	return error;

fs/ext4/ext4.h

+70 −0
Original line number Diff line number Diff line
@@ -1021,6 +1021,31 @@ struct ext4_inode_info { 


	struct list_head i_orphan;	/* unlinked but open inodes */



	/* Fast commit related info */



	struct list_head i_fc_list;	/*

					 * inodes that need fast commit

					 * 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;



	/* End of lblk range that needs to be committed in this fast commit */

	ext4_lblk_t i_fc_lblk_len;



	/* Number of ongoing updates on this inode */

	atomic_t  i_fc_updates;



	/* Fast commit wait queue for this inode */

	wait_queue_head_t i_fc_wait;



	/* Protect concurrent accesses on i_fc_lblk_start, i_fc_lblk_len */

	struct mutex i_fc_lock;



	/*

	 * i_disksize keeps track of what the inode size is ON DISK, not

	 * in memory.  During truncate, i_size is set to the new size by
@@ -1141,6 +1166,10 @@ struct ext4_inode_info { 
#define	EXT4_VALID_FS			0x0001	/* Unmounted cleanly */

#define	EXT4_ERROR_FS			0x0002	/* Errors detected */

#define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */

#define EXT4_FC_INELIGIBLE		0x0008	/* Fast commit ineligible */

#define EXT4_FC_COMMITTING		0x0010	/* File system underoing a fast

						 * commit.

						 */



/*

 * Misc. filesystem flags
@@ -1613,6 +1642,30 @@ struct ext4_sb_info { 
	/* Record the errseq of the backing block device */

	errseq_t s_bdev_wb_err;

	spinlock_t s_bdev_wb_lock;



	/* Ext4 fast commit stuff */

	atomic_t s_fc_subtid;

	atomic_t s_fc_ineligible_updates;

	/*

	 * After commit starts, the main queue gets locked, and the further

	 * updates get added in the staging queue.

	 */

#define FC_Q_MAIN	0

#define FC_Q_STAGING	1

	struct list_head s_fc_q[2];	/* Inodes staged for fast commit

					 * that have data changes in them.

					 */

	struct list_head s_fc_dentry_q[2];	/* directory entry updates */

	unsigned int s_fc_bytes;

	/*

	 * Main fast commit lock. This lock protects accesses to the

	 * following fields:

	 * ei->i_fc_list, s_fc_dentry_q, s_fc_q, s_fc_bytes, s_fc_bh.

	 */

	spinlock_t s_fc_lock;

	struct buffer_head *s_fc_bh;

	struct ext4_fc_stats s_fc_stats;

	u64 s_fc_avg_commit_time;

};



static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
@@ -1723,6 +1776,7 @@ enum { 
	EXT4_STATE_EXT_PRECACHED,	/* extents have been precached */

	EXT4_STATE_LUSTRE_EA_INODE,	/* Lustre-style ea_inode */

	EXT4_STATE_VERITY_IN_PROGRESS,	/* building fs-verity Merkle tree */

	EXT4_STATE_FC_COMMITTING,	/* Fast commit ongoing */

};



#define EXT4_INODE_BIT_FNS(name, field, offset)				\
@@ -2682,6 +2736,22 @@ extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate); 
/* fast_commit.c */



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,

			 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_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);

void ext4_fc_start_update(struct inode *inode);

void ext4_fc_stop_update(struct inode *inode);

void ext4_fc_del(struct inode *inode);

int ext4_fc_commit(journal_t *journal, tid_t commit_tid);

int __init ext4_fc_init_dentry_cache(void);



/* mballoc.c */

extern const struct seq_operations ext4_mb_seq_groups_ops;

extern long ext4_mb_stats;

fs/ext4/extents.c

+34 −14
Original line number Diff line number Diff line
@@ -3723,6 +3723,7 @@ 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;

}
@@ -3794,6 +3795,7 @@ 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;

}
@@ -4327,7 +4329,7 @@ got_allocated_blocks: 
	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);
@@ -4600,7 +4602,8 @@ 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,

			(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);

	if (ret >= 0)
@@ -4648,23 +4651,34 @@ 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);



	if (mode & FALLOC_FL_PUNCH_HOLE)

		return ext4_punch_hole(inode, offset, len);

	ext4_fc_start_update(inode);



	if (mode & FALLOC_FL_PUNCH_HOLE) {

		ret = ext4_punch_hole(inode, offset, len);

		goto exit;

	}



	ret = ext4_convert_inline_data(inode);

	if (ret)

		return ret;

		goto exit;



	if (mode & FALLOC_FL_COLLAPSE_RANGE)

		return ext4_collapse_range(inode, offset, len);



	if (mode & FALLOC_FL_INSERT_RANGE)

		return ext4_insert_range(inode, offset, len);

	if (mode & FALLOC_FL_COLLAPSE_RANGE) {

		ret = ext4_collapse_range(inode, offset, len);

		goto exit;

	}



	if (mode & FALLOC_FL_ZERO_RANGE)

		return ext4_zero_range(file, offset, len, mode);

	if (mode & FALLOC_FL_INSERT_RANGE) {

		ret = ext4_insert_range(inode, offset, len);

		goto exit;

	}



	if (mode & FALLOC_FL_ZERO_RANGE) {

		ret = ext4_zero_range(file, offset, len, mode);

		goto exit;

	}

	trace_ext4_fallocate_enter(inode, offset, len, mode);

	lblk = offset >> blkbits;
@@ -4698,12 +4712,14 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) 
		goto out;



	if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {

		ret = jbd2_complete_transaction(EXT4_SB(inode->i_sb)->s_journal,

		ret = ext4_fc_commit(EXT4_SB(inode->i_sb)->s_journal,

					EXT4_I(inode)->i_sync_tid);

	}

out:

	inode_unlock(inode);

	trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);

exit:

	ext4_fc_stop_update(inode);

	return ret;

}
@@ -5291,6 +5307,7 @@ static int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len) 
		ret = PTR_ERR(handle);

		goto out_mmap;

	}

	ext4_fc_start_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE);



	down_write(&EXT4_I(inode)->i_data_sem);

	ext4_discard_preallocations(inode, 0);
@@ -5329,6 +5346,7 @@ static int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len) 


out_stop:

	ext4_journal_stop(handle);

	ext4_fc_stop_ineligible(sb);

out_mmap:

	up_write(&EXT4_I(inode)->i_mmap_sem);

out_mutex:
@@ -5429,6 +5447,7 @@ static int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len) 
		ret = PTR_ERR(handle);

		goto out_mmap;

	}

	ext4_fc_start_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE);



	/* Expand file to avoid data loss if there is error while shifting */

	inode->i_size += len;
@@ -5503,6 +5522,7 @@ static int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len) 


out_stop:

	ext4_journal_stop(handle);

	ext4_fc_stop_ineligible(sb);

out_mmap:

	up_write(&EXT4_I(inode)->i_mmap_sem);

out_mutex:

fs/ext4/fast_commit.c

+1183 −0

File changed.

Preview size limit exceeded, changes collapsed.

fs/ext4/fast_commit.h

+110 −0
Original line number Diff line number Diff line
@@ -6,4 +6,114 @@ 
/* 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

#define EXT4_FC_TAG_CREAT		0x0003

#define EXT4_FC_TAG_LINK		0x0004

#define EXT4_FC_TAG_UNLINK		0x0005

#define EXT4_FC_TAG_INODE		0x0006

#define EXT4_FC_TAG_PAD			0x0007

#define EXT4_FC_TAG_TAIL		0x0008

#define EXT4_FC_TAG_HEAD		0x0009



#define EXT4_FC_SUPPORTED_FEATURES	0x0



/* On disk fast commit tlv value structures */



/* Fast commit on disk tag length structure */

struct ext4_fc_tl {

	__le16 fc_tag;

	__le16 fc_len;

};



/* Value structure for tag EXT4_FC_TAG_HEAD. */

struct ext4_fc_head {

	__le32 fc_features;

	__le32 fc_tid;

};



/* Value structure for EXT4_FC_TAG_ADD_RANGE. */

struct ext4_fc_add_range {

	__le32 fc_ino;

	__u8 fc_ex[12];

};



/* Value structure for tag EXT4_FC_TAG_DEL_RANGE. */

struct ext4_fc_del_range {

	__le32 fc_ino;

	__le32 fc_lblk;

	__le32 fc_len;

};



/*

 * This is the value structure for tags EXT4_FC_TAG_CREAT, EXT4_FC_TAG_LINK

 * and EXT4_FC_TAG_UNLINK.

 */

struct ext4_fc_dentry_info {

	__le32 fc_parent_ino;

	__le32 fc_ino;

	u8 fc_dname[0];

};



/* Value structure for EXT4_FC_TAG_INODE and EXT4_FC_TAG_INODE_PARTIAL. */

struct ext4_fc_inode {

	__le32 fc_ino;

	__u8 fc_raw_inode[0];

};



/* Value structure for tag EXT4_FC_TAG_TAIL. */

struct ext4_fc_tail {

	__le32 fc_tid;

	__le32 fc_crc;

};



/*

 * In memory list of dentry updates that are performed on the file

 * system used by fast commit code.

 */

struct ext4_fc_dentry_update {

	int fcd_op;		/* Type of update create / unlink / link */

	int fcd_parent;		/* Parent inode number */

	int fcd_ino;		/* Inode number */

	struct qstr fcd_name;	/* Dirent name */

	unsigned char fcd_iname[DNAME_INLINE_LEN];	/* Dirent name string */

	struct list_head fcd_list;

};



/*

 * Fast commit reason codes

 */

enum {

	/*

	 * Commit status codes:

	 */

	EXT4_FC_REASON_OK = 0,

	EXT4_FC_REASON_INELIGIBLE,

	EXT4_FC_REASON_ALREADY_COMMITTED,

	EXT4_FC_REASON_FC_START_FAILED,

	EXT4_FC_REASON_FC_FAILED,



	/*

	 * Fast commit ineligiblity reasons:

	 */

	EXT4_FC_REASON_XATTR = 0,

	EXT4_FC_REASON_CROSS_RENAME,

	EXT4_FC_REASON_JOURNAL_FLAG_CHANGE,

	EXT4_FC_REASON_MEM,

	EXT4_FC_REASON_SWAP_BOOT,

	EXT4_FC_REASON_RESIZE,

	EXT4_FC_REASON_RENAME_DIR,

	EXT4_FC_REASON_FALLOC_RANGE,

	EXT4_FC_COMMIT_FAILED,

	EXT4_FC_REASON_MAX

};



struct ext4_fc_stats {

	unsigned int fc_ineligible_reason_count[EXT4_FC_REASON_MAX];

	unsigned long fc_num_commits;

	unsigned long fc_ineligible_commits;

	unsigned long fc_numblks;

};



#endif /* __FAST_COMMIT_H__ */

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