Commit 622daaff authored by Ryusuke Konishi's avatar Ryusuke Konishi
Browse files

nilfs2: fiemap support 



This adds fiemap to nilfs.  Two new functions, nilfs_fiemap and
nilfs_find_uncommitted_extent are added.

nilfs_fiemap() implements the fiemap inode operation, and
nilfs_find_uncommitted_extent() helps to get a range of data blocks
whose physical location has not been determined.

nilfs_fiemap() collects extent information by looping through
nilfs_bmap_lookup_contig and nilfs_find_uncommitted_extent routines.

Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
parent 27e6c7a3

fs/nilfs2/file.c

+1 −0
Original line number Diff line number Diff line
@@ -155,6 +155,7 @@ const struct inode_operations nilfs_file_inode_operations = { 
	.truncate	= nilfs_truncate,

	.setattr	= nilfs_setattr,

	.permission     = nilfs_permission,

	.fiemap		= nilfs_fiemap,

};



/* end of file */

fs/nilfs2/inode.c

+131 −0
Original line number Diff line number Diff line
@@ -916,3 +916,134 @@ void nilfs_dirty_inode(struct inode *inode) 
	nilfs_mark_inode_dirty(inode);

	nilfs_transaction_commit(inode->i_sb); /* never fails */

}



int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,

		 __u64 start, __u64 len)

{

	struct the_nilfs *nilfs = NILFS_I_NILFS(inode);

	__u64 logical = 0, phys = 0, size = 0;

	__u32 flags = 0;

	loff_t isize;

	sector_t blkoff, end_blkoff;

	sector_t delalloc_blkoff;

	unsigned long delalloc_blklen;

	unsigned int blkbits = inode->i_blkbits;

	int ret, n;



	ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);

	if (ret)

		return ret;



	mutex_lock(&inode->i_mutex);



	isize = i_size_read(inode);



	blkoff = start >> blkbits;

	end_blkoff = (start + len - 1) >> blkbits;



	delalloc_blklen = nilfs_find_uncommitted_extent(inode, blkoff,

							&delalloc_blkoff);



	do {

		__u64 blkphy;

		unsigned int maxblocks;



		if (delalloc_blklen && blkoff == delalloc_blkoff) {

			if (size) {

				/* End of the current extent */

				ret = fiemap_fill_next_extent(

					fieinfo, logical, phys, size, flags);

				if (ret)

					break;

			}

			if (blkoff > end_blkoff)

				break;



			flags = FIEMAP_EXTENT_MERGED | FIEMAP_EXTENT_DELALLOC;

			logical = blkoff << blkbits;

			phys = 0;

			size = delalloc_blklen << blkbits;



			blkoff = delalloc_blkoff + delalloc_blklen;

			delalloc_blklen = nilfs_find_uncommitted_extent(

				inode, blkoff, &delalloc_blkoff);

			continue;

		}



		/*

		 * Limit the number of blocks that we look up so as

		 * not to get into the next delayed allocation extent.

		 */

		maxblocks = INT_MAX;

		if (delalloc_blklen)

			maxblocks = min_t(sector_t, delalloc_blkoff - blkoff,

					  maxblocks);

		blkphy = 0;



		down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);

		n = nilfs_bmap_lookup_contig(

			NILFS_I(inode)->i_bmap, blkoff, &blkphy, maxblocks);

		up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);



		if (n < 0) {

			int past_eof;



			if (unlikely(n != -ENOENT))

				break; /* error */



			/* HOLE */

			blkoff++;

			past_eof = ((blkoff << blkbits) >= isize);



			if (size) {

				/* End of the current extent */



				if (past_eof)

					flags |= FIEMAP_EXTENT_LAST;



				ret = fiemap_fill_next_extent(

					fieinfo, logical, phys, size, flags);

				if (ret)

					break;

				size = 0;

			}

			if (blkoff > end_blkoff || past_eof)

				break;

		} else {

			if (size) {

				if (phys && blkphy << blkbits == phys + size) {

					/* The current extent goes on */

					size += n << blkbits;

				} else {

					/* Terminate the current extent */

					ret = fiemap_fill_next_extent(

						fieinfo, logical, phys, size,

						flags);

					if (ret || blkoff > end_blkoff)

						break;



					/* Start another extent */

					flags = FIEMAP_EXTENT_MERGED;

					logical = blkoff << blkbits;

					phys = blkphy << blkbits;

					size = n << blkbits;

				}

			} else {

				/* Start a new extent */

				flags = FIEMAP_EXTENT_MERGED;

				logical = blkoff << blkbits;

				phys = blkphy << blkbits;

				size = n << blkbits;

			}

			blkoff += n;

		}

		cond_resched();

	} while (true);



	/* If ret is 1 then we just hit the end of the extent array */

	if (ret == 1)

		ret = 0;



	mutex_unlock(&inode->i_mutex);

	return ret;

}

fs/nilfs2/namei.c

+1 −0
Original line number Diff line number Diff line
@@ -577,6 +577,7 @@ const struct inode_operations nilfs_dir_inode_operations = { 
	.rename		= nilfs_rename,

	.setattr	= nilfs_setattr,

	.permission	= nilfs_permission,

	.fiemap		= nilfs_fiemap,

};



const struct inode_operations nilfs_special_inode_operations = {

fs/nilfs2/nilfs.h

+2 −0
Original line number Diff line number Diff line
@@ -264,6 +264,8 @@ extern int nilfs_set_file_dirty(struct nilfs_sb_info *, struct inode *, 
				unsigned);

extern int nilfs_mark_inode_dirty(struct inode *);

extern void nilfs_dirty_inode(struct inode *);

int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,

		 __u64 start, __u64 len);



/* super.c */

extern struct inode *nilfs_alloc_inode(struct super_block *);

fs/nilfs2/page.c

+84 −0
Original line number Diff line number Diff line
@@ -546,3 +546,87 @@ int __nilfs_clear_page_dirty(struct page *page) 
	}

	return TestClearPageDirty(page);

}



/**

 * nilfs_find_uncommitted_extent - find extent of uncommitted data

 * @inode: inode

 * @start_blk: start block offset (in)

 * @blkoff: start offset of the found extent (out)

 *

 * This function searches an extent of buffers marked "delayed" which

 * starts from a block offset equal to or larger than @start_blk.  If

 * such an extent was found, this will store the start offset in

 * @blkoff and return its length in blocks.  Otherwise, zero is

 * returned.

 */

unsigned long nilfs_find_uncommitted_extent(struct inode *inode,

					    sector_t start_blk,

					    sector_t *blkoff)

{

	unsigned int i;

	pgoff_t index;

	unsigned int nblocks_in_page;

	unsigned long length = 0;

	sector_t b;

	struct pagevec pvec;

	struct page *page;



	if (inode->i_mapping->nrpages == 0)

		return 0;



	index = start_blk >> (PAGE_CACHE_SHIFT - inode->i_blkbits);

	nblocks_in_page = 1U << (PAGE_CACHE_SHIFT - inode->i_blkbits);



	pagevec_init(&pvec, 0);



repeat:

	pvec.nr = find_get_pages_contig(inode->i_mapping, index, PAGEVEC_SIZE,

					pvec.pages);

	if (pvec.nr == 0)

		return length;



	if (length > 0 && pvec.pages[0]->index > index)

		goto out;



	b = pvec.pages[0]->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);

	i = 0;

	do {

		page = pvec.pages[i];



		lock_page(page);

		if (page_has_buffers(page)) {

			struct buffer_head *bh, *head;



			bh = head = page_buffers(page);

			do {

				if (b < start_blk)

					continue;

				if (buffer_delay(bh)) {

					if (length == 0)

						*blkoff = b;

					length++;

				} else if (length > 0) {

					goto out_locked;

				}

			} while (++b, bh = bh->b_this_page, bh != head);

		} else {

			if (length > 0)

				goto out_locked;



			b += nblocks_in_page;

		}

		unlock_page(page);



	} while (++i < pagevec_count(&pvec));



	index = page->index + 1;

	pagevec_release(&pvec);

	cond_resched();

	goto repeat;



out_locked:

	unlock_page(page);

out:

	pagevec_release(&pvec);

	return length;

}

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