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Commit c7ef972c authored by Vyacheslav Dubeyko's avatar Vyacheslav Dubeyko Committed by Linus Torvalds
Browse files

nilfs2: implement calculation of free inodes count 



Currently, NILFS2 returns 0 as free inodes count (f_ffree) and current
used inodes count as total file nodes in file system (f_files):

df -i
Filesystem      Inodes  IUsed   IFree IUse% Mounted on
/dev/loop0           2      2       0  100% /mnt/nilfs2

This patch implements real calculation of free inodes count.  First of
all, it is calculated total file nodes in file system as
(desc_blocks_count * groups_per_desc_block * entries_per_group).  Then, it
is calculated free inodes count as difference the total file nodes and
used inodes count.  As a result, we have such output for NILFS2:

df -i
Filesystem       Inodes   IUsed    IFree IUse% Mounted on
/dev/loop0      4194304 2114701  2079603   51% /mnt/nilfs2

Reported-by: default avatarClemens Eisserer <linuxhippy@gmail.com>
Signed-off-by: default avatarVyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: default avatarVyacheslav Dubeyko <slava@dubeyko.com>
Cc: Joern Engel <joern@logfs.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e88b815e

fs/nilfs2/alloc.c

+63 −0
Original line number Diff line number Diff line
@@ -397,6 +397,69 @@ nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode, 
		     max - curr + 1);

}



/**

 * nilfs_palloc_count_desc_blocks - count descriptor blocks number

 * @inode: inode of metadata file using this allocator

 * @desc_blocks: descriptor blocks number [out]

 */

static int nilfs_palloc_count_desc_blocks(struct inode *inode,

					    unsigned long *desc_blocks)

{

	unsigned long blknum;

	int ret;



	ret = nilfs_bmap_last_key(NILFS_I(inode)->i_bmap, &blknum);

	if (likely(!ret))

		*desc_blocks = DIV_ROUND_UP(

			blknum, NILFS_MDT(inode)->mi_blocks_per_desc_block);

	return ret;

}



/**

 * nilfs_palloc_mdt_file_can_grow - check potential opportunity for

 *					MDT file growing

 * @inode: inode of metadata file using this allocator

 * @desc_blocks: known current descriptor blocks count

 */

static inline bool nilfs_palloc_mdt_file_can_grow(struct inode *inode,

						    unsigned long desc_blocks)

{

	return (nilfs_palloc_groups_per_desc_block(inode) * desc_blocks) <

			nilfs_palloc_groups_count(inode);

}



/**

 * nilfs_palloc_count_max_entries - count max number of entries that can be

 *					described by descriptor blocks count

 * @inode: inode of metadata file using this allocator

 * @nused: current number of used entries

 * @nmaxp: max number of entries [out]

 */

int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)

{

	unsigned long desc_blocks = 0;

	u64 entries_per_desc_block, nmax;

	int err;



	err = nilfs_palloc_count_desc_blocks(inode, &desc_blocks);

	if (unlikely(err))

		return err;



	entries_per_desc_block = (u64)nilfs_palloc_entries_per_group(inode) *

				nilfs_palloc_groups_per_desc_block(inode);

	nmax = entries_per_desc_block * desc_blocks;



	if (nused == nmax &&

			nilfs_palloc_mdt_file_can_grow(inode, desc_blocks))

		nmax += entries_per_desc_block;



	if (nused > nmax)

		return -ERANGE;



	*nmaxp = nmax;

	return 0;

}



/**

 * nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object

 * @inode: inode of metadata file using this allocator

fs/nilfs2/alloc.h

+2 −0
Original line number Diff line number Diff line
@@ -48,6 +48,8 @@ int nilfs_palloc_get_entry_block(struct inode *, __u64, int, 
void *nilfs_palloc_block_get_entry(const struct inode *, __u64,

				   const struct buffer_head *, void *);



int nilfs_palloc_count_max_entries(struct inode *, u64, u64 *);



/**

 * nilfs_palloc_req - persistent allocator request and reply

 * @pr_entry_nr: entry number (vblocknr or inode number)

fs/nilfs2/ifile.c

+22 −0
Original line number Diff line number Diff line
@@ -159,6 +159,28 @@ int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino, 
	return err;

}



/**

 * nilfs_ifile_count_free_inodes - calculate free inodes count

 * @ifile: ifile inode

 * @nmaxinodes: current maximum of available inodes count [out]

 * @nfreeinodes: free inodes count [out]

 */

int nilfs_ifile_count_free_inodes(struct inode *ifile,

				    u64 *nmaxinodes, u64 *nfreeinodes)

{

	u64 nused;

	int err;



	*nmaxinodes = 0;

	*nfreeinodes = 0;



	nused = atomic_read(&NILFS_I(ifile)->i_root->inodes_count);

	err = nilfs_palloc_count_max_entries(ifile, nused, nmaxinodes);

	if (likely(!err))

		*nfreeinodes = *nmaxinodes - nused;

	return err;

}



/**

 * nilfs_ifile_read - read or get ifile inode

 * @sb: super block instance

fs/nilfs2/ifile.h

+2 −0
Original line number Diff line number Diff line
@@ -49,6 +49,8 @@ int nilfs_ifile_create_inode(struct inode *, ino_t *, struct buffer_head **); 
int nilfs_ifile_delete_inode(struct inode *, ino_t);

int nilfs_ifile_get_inode_block(struct inode *, ino_t, struct buffer_head **);



int nilfs_ifile_count_free_inodes(struct inode *, u64 *, u64 *);



int nilfs_ifile_read(struct super_block *sb, struct nilfs_root *root,

		     size_t inode_size, struct nilfs_inode *raw_inode,

		     struct inode **inodep);

fs/nilfs2/super.c

+23 −2
Original line number Diff line number Diff line
@@ -609,6 +609,7 @@ static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) 
	unsigned long overhead;

	unsigned long nrsvblocks;

	sector_t nfreeblocks;

	u64 nmaxinodes, nfreeinodes;

	int err;



	/*
@@ -633,14 +634,34 @@ static int nilfs_statfs(struct dentry *dentry, struct kstatfs *buf) 
	if (unlikely(err))

		return err;



	err = nilfs_ifile_count_free_inodes(root->ifile,

					    &nmaxinodes, &nfreeinodes);

	if (unlikely(err)) {

		printk(KERN_WARNING

			"NILFS warning: fail to count free inodes: err %d.\n",

			err);

		if (err == -ERANGE) {

			/*

			 * If nilfs_palloc_count_max_entries() returns

			 * -ERANGE error code then we simply treat

			 * curent inodes count as maximum possible and

			 * zero as free inodes value.

			 */

			nmaxinodes = atomic_read(&root->inodes_count);

			nfreeinodes = 0;

			err = 0;

		} else

			return err;

	}



	buf->f_type = NILFS_SUPER_MAGIC;

	buf->f_bsize = sb->s_blocksize;

	buf->f_blocks = blocks - overhead;

	buf->f_bfree = nfreeblocks;

	buf->f_bavail = (buf->f_bfree >= nrsvblocks) ?

		(buf->f_bfree - nrsvblocks) : 0;

	buf->f_files = atomic_read(&root->inodes_count);

	buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */

	buf->f_files = nmaxinodes;

	buf->f_ffree = nfreeinodes;

	buf->f_namelen = NILFS_NAME_LEN;

	buf->f_fsid.val[0] = (u32)id;

	buf->f_fsid.val[1] = (u32)(id >> 32);