nilfs2: improve execution time of NILFS_IOCTL_GET_CPINFO ioctl (53a2c3bd) · Commits · 戴 / test

fs/nilfs2/cpfile.c

+52 −6

Original line number	Diff line number	Diff line
		@@ -53,6 +53,13 @@ nilfs_cpfile_get_offset(const struct inode *cpfile, __u64 cno)
		return do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile));
		}

		static __u64 nilfs_cpfile_first_checkpoint_in_block(const struct inode *cpfile,
		unsigned long blkoff)
		{
		return (__u64)nilfs_cpfile_checkpoints_per_block(cpfile) * blkoff
		+ 1 - NILFS_MDT(cpfile)->mi_first_entry_offset;
		}

		static unsigned long
		nilfs_cpfile_checkpoints_in_block(const struct inode *cpfile,
		__u64 curr,
		@@ -146,6 +153,44 @@ static inline int nilfs_cpfile_get_checkpoint_block(struct inode *cpfile,
		create, nilfs_cpfile_block_init, bhp);
		}

		/**
		* nilfs_cpfile_find_checkpoint_block - find and get a buffer on cpfile
		* @cpfile: inode of cpfile
		* @start_cno: start checkpoint number (inclusive)
		* @end_cno: end checkpoint number (inclusive)
		* @cnop: place to store the next checkpoint number
		* @bhp: place to store a pointer to buffer_head struct
		*
		* Return Value: On success, it returns 0. On error, the following negative
		* error code is returned.
		*
		* %-ENOMEM - Insufficient memory available.
		*
		* %-EIO - I/O error
		*
		* %-ENOENT - no block exists in the range.
		*/
		static int nilfs_cpfile_find_checkpoint_block(struct inode *cpfile,
		__u64 start_cno, __u64 end_cno,
		__u64 *cnop,
		struct buffer_head **bhp)
		{
		unsigned long start, end, blkoff;
		int ret;

		if (unlikely(start_cno > end_cno))
		return -ENOENT;

		start = nilfs_cpfile_get_blkoff(cpfile, start_cno);
		end = nilfs_cpfile_get_blkoff(cpfile, end_cno);

		ret = nilfs_mdt_find_block(cpfile, start, end, &blkoff, bhp);
		if (!ret)
		*cnop = (blkoff == start) ? start_cno :
		nilfs_cpfile_first_checkpoint_in_block(cpfile, blkoff);
		return ret;
		}

		static inline int nilfs_cpfile_delete_checkpoint_block(struct inode *cpfile,
		__u64 cno)
		{
		@@ -403,14 +448,15 @@ static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode cpfile, __u64 cnop,
		return -ENOENT; /* checkpoint number 0 is invalid */
		down_read(&NILFS_MDT(cpfile)->mi_sem);

		for (n = 0; cno < cur_cno && n < nci; cno += ncps) {
		ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno);
		ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh);
		for (n = 0; n < nci; cno += ncps) {
		ret = nilfs_cpfile_find_checkpoint_block(
		cpfile, cno, cur_cno - 1, &cno, &bh);
		if (ret < 0) {
		if (ret != -ENOENT)
		if (likely(ret == -ENOENT))
		break;
		goto out;
		continue; /* skip hole */
		}
		ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno);

		kaddr = kmap_atomic(bh->b_page);
		cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);

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