On Wed, 22 May 2013 10:23:47 +0400, Vyacheslav Dubeyko wrote: > Hi Ryusuke, > > This is fourth version of the patch. I reworked representation of > mi_desc_blocks_count because I think that using this field is good > solution for calculation of max entries count.
Nack. Please stop switching atomic_t and atomic64_t in nilfs with heavy use of ifdef macros and inline functions. It is seriously hurting the readability and simplicity of source code. Consider using "atomic_long_t", and please try to keep the patch simple. In my opinion, mi_desc_blocks_count is no longer needed because nilfs_bmap_last_key is not so heavy. But, I don't deny adding this counter. > By the way, I see that it is used atomic_t type for representation > of inodes_count and blocks_count fields in nilfs_root structure. > Maybe it makes sense to rework representation of these fields too. > What do you think? Yes, looks like they should be replaced with atomic_long_t type counters (with a separate patch, of course). Regards, Ryusuke Konishi > v3->v4 > * The desc_blocks value is represented by unsigned long type. > * The nilfs_palloc_count_desc_blocks() method is simplified. > * The mi_desc_blocks_count field of nilfs_mdt_info structure > is represented as atomic64_t for the case of CONFIG_64BIT and > as atomic_t for other cases. > > 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 v4] 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]> > Signed-off-by: Ryusuke Konishi <[email protected]> > Tested-by: Vyacheslav Dubeyko <[email protected]> > --- > fs/nilfs2/alloc.c | 78 > +++++++++++++++++++++++++++++++++++++++++++++++++++++ > fs/nilfs2/alloc.h | 2 ++ > fs/nilfs2/ifile.c | 22 +++++++++++++++ > fs/nilfs2/ifile.h | 2 +- > fs/nilfs2/mdt.h | 26 ++++++++++++++++++ > fs/nilfs2/super.c | 25 +++++++++++++++-- > 6 files changed, 152 insertions(+), 3 deletions(-) > > diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c > index eed4d7b..e5ea7b3 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 */ > + nilfs_mdt_set_desc_blocks(mi, 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 +405,77 @@ 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 > + * @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; > + u64 entries_per_desc_block, nmax; > + int err; > + > + desc_blocks = nilfs_mdt_read_desc_blocks(NILFS_MDT(inode)); > + 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; <snip> -- 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
