Пример #1
0
int nilfs_get_block(struct inode *inode, sector_t blkoff,
		    struct buffer_head *bh_result, int create)
{
	struct nilfs_inode_info *ii = NILFS_I(inode);
	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
	__u64 blknum = 0;
	int err = 0, ret;
	unsigned maxblocks = bh_result->b_size >> inode->i_blkbits;

	down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
	ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
	if (ret >= 0) {	
		map_bh(bh_result, inode->i_sb, blknum);
		if (ret > 0)
			bh_result->b_size = (ret << inode->i_blkbits);
		goto out;
	}
	
	if (ret == -ENOENT && create) {
		struct nilfs_transaction_info ti;

		bh_result->b_blocknr = 0;
		err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
		if (unlikely(err))
			goto out;
		err = nilfs_bmap_insert(ii->i_bmap, (unsigned long)blkoff,
					(unsigned long)bh_result);
		if (unlikely(err != 0)) {
			if (err == -EEXIST) {
				printk(KERN_WARNING
				       "nilfs_get_block: a race condition "
				       "while inserting a data block. "
				       "(inode number=%lu, file block "
				       "offset=%llu)\n",
				       inode->i_ino,
				       (unsigned long long)blkoff);
				err = 0;
			}
			nilfs_transaction_abort(inode->i_sb);
			goto out;
		}
		nilfs_mark_inode_dirty(inode);
		nilfs_transaction_commit(inode->i_sb); 
		
		set_buffer_new(bh_result);
		set_buffer_delay(bh_result);
		map_bh(bh_result, inode->i_sb, 0); 
	} else if (ret == -ENOENT) {
		;
	} else {
		err = ret;
	}

 out:
	return err;
}
Пример #2
0
int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
		 __u64 start, __u64 len)
{
	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
	__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;
}
Пример #3
0
/**
 * nilfs_get_block() - get a file block on the filesystem (callback function)
 * @inode - inode struct of the target file
 * @blkoff - file block number
 * @bh_result - buffer head to be mapped on
 * @create - indicate whether allocating the block or not when it has not
 *      been allocated yet.
 *
 * This function does not issue actual read request of the specified data
 * block. It is done by VFS.
 */
int nilfs_get_block(struct inode *inode, sector_t blkoff,
		    struct buffer_head *bh_result, int create)
{
	struct nilfs_inode_info *ii = NILFS_I(inode);
	struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
	__u64 blknum = 0;
	int err = 0, ret;
	unsigned maxblocks = bh_result->b_size >> inode->i_blkbits;

	down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
	ret = nilfs_bmap_lookup_contig(ii->i_bmap, blkoff, &blknum, maxblocks);
	up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
	if (ret >= 0) {	/* found */
		map_bh(bh_result, inode->i_sb, blknum);
		if (ret > 0)
			bh_result->b_size = (ret << inode->i_blkbits);
		goto out;
	}
	/* data block was not found */
	if (ret == -ENOENT && create) {
		struct nilfs_transaction_info ti;

		bh_result->b_blocknr = 0;
		err = nilfs_transaction_begin(inode->i_sb, &ti, 1);
		if (unlikely(err))
			goto out;
		err = nilfs_bmap_insert(ii->i_bmap, (unsigned long)blkoff,
					(unsigned long)bh_result);
		if (unlikely(err != 0)) {
			if (err == -EEXIST) {
				/*
				 * The get_block() function could be called
				 * from multiple callers for an inode.
				 * However, the page having this block must
				 * be locked in this case.
				 */
				printk(KERN_WARNING
				       "nilfs_get_block: a race condition "
				       "while inserting a data block. "
				       "(inode number=%lu, file block "
				       "offset=%llu)\n",
				       inode->i_ino,
				       (unsigned long long)blkoff);
				err = 0;
			}
			nilfs_transaction_abort(inode->i_sb);
			goto out;
		}
		nilfs_mark_inode_dirty(inode);
		nilfs_transaction_commit(inode->i_sb); /* never fails */
		/* Error handling should be detailed */
		set_buffer_new(bh_result);
		set_buffer_delay(bh_result);
		map_bh(bh_result, inode->i_sb, 0); /* dbn must be changed
						      to proper value */
	} else if (ret == -ENOENT) {
		/* not found is not error (e.g. hole); must return without
		   the mapped state flag. */
		;
	} else {
		err = ret;
	}

 out:
	return err;
}