Hi Ryusuke, This is third version of the patch.
v2->v3 * Trivial BUG_ON checks were removed. * Whole calculation algorithm was moved into nilfs_palloc_count_max_entries() method. * Improve error processing in the code. * The nilfs_palloc_mdt_file_can_grow() method was simplified. * The nilfs_ifile_count_free_inodes() method was simplified. v1->v2 * Change __statfs_word on u64 type. * Rename nilfs_count_free_inodes() into nilfs_ifile_count_free_inodes() method. * Introduce auxiliary functions: nilfs_palloc_count_max_entries(), nilfs_palloc_count_desc_blocks(), nilfs_palloc_mdt_file_can_grow(). * Rework processing of returned error from nilfs_ifile_count_free_inodes() in nilfs_statfs(). With the best regards, Vyacheslav Dubeyko. --- From: Vyacheslav Dubeyko <[email protected]> Subject: [PATCH v3] 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: Clemens Eisserer <[email protected]> Signed-off-by: Vyacheslav Dubeyko <[email protected]> CC: Ryusuke Konishi <[email protected]> Tested-by: Vyacheslav Dubeyko <[email protected]> --- fs/nilfs2/alloc.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/nilfs2/alloc.h | 2 ++ fs/nilfs2/ifile.c | 22 ++++++++++++ fs/nilfs2/ifile.h | 2 +- fs/nilfs2/mdt.h | 2 ++ fs/nilfs2/super.c | 24 ++++++++++++-- 6 files changed, 145 insertions(+), 3 deletions(-) diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c index eed4d7b..2727713 100644 --- a/fs/nilfs2/alloc.c +++ b/fs/nilfs2/alloc.c @@ -80,6 +80,13 @@ int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned entry_size) mi->mi_blocks_per_group + 1; /* Number of blocks per descriptor including the descriptor block */ + atomic_set(&mi->mi_desc_blocks_count, 1); + /* + * The field mi_desc_blocks_count is used for + * storing knowledge about current count of + * desciptor blocks. Initially, it is initialized + * by one. + */ return 0; } @@ -398,6 +405,95 @@ nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode, } /** + * nilfs_palloc_count_desc_blocks - count descriptor blocks number + * @inode: inode of metadata file using this allocator + * @start_desc_blks: known current descriptor blocks count + * @desc_blocksp: calculated descriptor blocks number [out] + */ +static int nilfs_palloc_count_desc_blocks(struct inode *inode, + unsigned int start_desc_blks, + unsigned int *desc_blocksp) +{ + unsigned long ngroups = nilfs_palloc_groups_count(inode); + unsigned long groups_per_desc_block = + nilfs_palloc_groups_per_desc_block(inode); + struct buffer_head *desc_bh; + unsigned long group = + groups_per_desc_block * (unsigned long)start_desc_blks; + unsigned int desc_blocks; + int err; + + *desc_blocksp = desc_blocks = start_desc_blks; + for (; group < ngroups; group += groups_per_desc_block) { + err = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh); + if (err) { + if (err == -ENOENT) + break; + return err; + } + desc_blocks++; + brelse(desc_bh); + } + + *desc_blocksp = desc_blocks; + return 0; +} + +/** + * 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 int desc_blocks) +{ + return (nilfs_palloc_groups_per_desc_block(inode) * (u64)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 int desc_blocks; + u64 entries_per_desc_block, nmax; + int err; + + desc_blocks = atomic_read(&NILFS_MDT(inode)->mi_desc_blocks_count); + entries_per_desc_block = (u64)nilfs_palloc_entries_per_group(inode) * + nilfs_palloc_groups_per_desc_block(inode); + + nmax = entries_per_desc_block * (u64)desc_blocks; + if (nused >= nmax) { + err = nilfs_palloc_count_desc_blocks(inode, desc_blocks, + &desc_blocks); + if (unlikely(err)) + return err; + + nmax = entries_per_desc_block * (u64)desc_blocks; + if (nused == nmax && + nilfs_palloc_mdt_file_can_grow(inode, + desc_blocks)) { + nmax += entries_per_desc_block; + ++desc_blocks; + } + atomic_set(&NILFS_MDT(inode)->mi_desc_blocks_count, + desc_blocks); + + 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 * @req: nilfs_palloc_req structure exchanged for the allocation diff --git a/fs/nilfs2/alloc.h b/fs/nilfs2/alloc.h index fb72381..4bd6451 100644 --- a/fs/nilfs2/alloc.h +++ b/fs/nilfs2/alloc.h @@ -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) diff --git a/fs/nilfs2/ifile.c b/fs/nilfs2/ifile.c index d8e65bd..d788a59 100644 --- a/fs/nilfs2/ifile.c +++ b/fs/nilfs2/ifile.c @@ -160,6 +160,28 @@ int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino, } /** + * 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 * @root: root object diff --git a/fs/nilfs2/ifile.h b/fs/nilfs2/ifile.h index 59b6f2b..e9ceb27 100644 --- a/fs/nilfs2/ifile.h +++ b/fs/nilfs2/ifile.h @@ -48,7 +48,7 @@ static inline void nilfs_ifile_unmap_inode(struct inode *ifile, ino_t ino, 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); diff --git a/fs/nilfs2/mdt.h b/fs/nilfs2/mdt.h index ab172e8..c01b6fb 100644 --- a/fs/nilfs2/mdt.h +++ b/fs/nilfs2/mdt.h @@ -53,6 +53,7 @@ struct nilfs_shadow_map { * @mi_shadow: shadow of bmap and page caches * @mi_blocks_per_group: number of blocks in a group * @mi_blocks_per_desc_block: number of blocks per descriptor block + * @mi_desc_blocks_count: number of descriptor blocks */ struct nilfs_mdt_info { struct rw_semaphore mi_sem; @@ -64,6 +65,7 @@ struct nilfs_mdt_info { struct nilfs_shadow_map *mi_shadow; unsigned long mi_blocks_per_group; unsigned long mi_blocks_per_desc_block; + atomic_t mi_desc_blocks_count; }; static inline struct nilfs_mdt_info *NILFS_MDT(const struct inode *inode) diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index c7d1f9f..2b908a6 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -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 +634,33 @@ 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; + } 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); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
