This patch introduces the nilfs_palloc_scan_entries() function, which takes an inode of one of nilfs' meta data files and iterates through all of its entries. For each entry the callback function pointer that is given as a parameter is called. The data parameter is passed to the callback function, so that it may receive parameters and return results.
Signed-off-by: Andreas Rohner <[email protected]> --- fs/nilfs2/alloc.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/nilfs2/alloc.h | 6 +++ 2 files changed, 127 insertions(+) diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c index 741fd02..0edd85a 100644 --- a/fs/nilfs2/alloc.c +++ b/fs/nilfs2/alloc.c @@ -545,6 +545,127 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode, } /** + * nilfs_palloc_scan_entries - scan through every entry and execute dofunc + * @inode: inode of metadata file using this allocator + * @dofunc: function executed for every entry + * @data: data pointer passed to dofunc + * + * Description: nilfs_palloc_scan_entries() walks through every allocated entry + * of a metadata file and executes dofunc on it. It passes a data pointer to + * dofunc, which can be used as an input parameter or for returning of results. + * + * Return Value: On success, 0 is returned. On error, a + * negative error code is returned. + */ +int nilfs_palloc_scan_entries(struct inode *inode, + void (*dofunc)(struct inode *, + struct nilfs_palloc_req *, + void *), + void *data) +{ + struct buffer_head *desc_bh, *bitmap_bh; + struct nilfs_palloc_group_desc *desc; + struct nilfs_palloc_req req; + unsigned char *bitmap; + void *desc_kaddr, *bitmap_kaddr; + unsigned long group, maxgroup, ngroups; + unsigned long n, m, entries_per_group, groups_per_desc_block; + unsigned long i, j, pos; + unsigned long blkoff, prev_blkoff; + int ret; + + ngroups = nilfs_palloc_groups_count(inode); + maxgroup = ngroups - 1; + entries_per_group = nilfs_palloc_entries_per_group(inode); + groups_per_desc_block = nilfs_palloc_groups_per_desc_block(inode); + + for (group = 0; group < ngroups;) { + ret = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh); + if (ret == -ENOENT) + return 0; + else if (ret < 0) + return ret; + req.pr_desc_bh = desc_bh; + desc_kaddr = kmap(desc_bh->b_page); + desc = nilfs_palloc_block_get_group_desc(inode, group, + desc_bh, desc_kaddr); + n = nilfs_palloc_rest_groups_in_desc_block(inode, group, + maxgroup); + + for (i = 0; i < n; i++, desc++, group++) { + m = entries_per_group - + nilfs_palloc_group_desc_nfrees(inode, + group, desc); + if (!m) + continue; + + ret = nilfs_palloc_get_bitmap_block( + inode, group, 0, &bitmap_bh); + if (ret == -ENOENT) { + ret = 0; + goto out_desc; + } else if (ret < 0) + goto out_desc; + + req.pr_bitmap_bh = bitmap_bh; + bitmap_kaddr = kmap(bitmap_bh->b_page); + bitmap = bitmap_kaddr + bh_offset(bitmap_bh); + /* entry blkoff is always bigger than 0 */ + blkoff = 0; + pos = 0; + + for (j = 0; j < m; ++j, ++pos) { + pos = nilfs_find_next_bit(bitmap, + entries_per_group, pos); + + if (pos >= entries_per_group) + break; + + /* found an entry */ + req.pr_entry_nr = + entries_per_group * group + pos; + + prev_blkoff = blkoff; + blkoff = nilfs_palloc_entry_blkoff(inode, + req.pr_entry_nr); + + if (blkoff != prev_blkoff) { + if (prev_blkoff) + brelse(req.pr_entry_bh); + + ret = nilfs_palloc_get_entry_block( + inode, req.pr_entry_nr, + 0, &req.pr_entry_bh); + if (ret < 0) + goto out_entry; + } + + dofunc(inode, &req, data); + } + + if (blkoff) + brelse(req.pr_entry_bh); + kunmap(bitmap_bh->b_page); + brelse(bitmap_bh); + } + + kunmap(desc_bh->b_page); + brelse(desc_bh); + } + + return 0; + +out_entry: + kunmap(bitmap_bh->b_page); + brelse(bitmap_bh); + +out_desc: + kunmap(desc_bh->b_page); + brelse(desc_bh); + return ret; +} + +/** * nilfs_palloc_commit_alloc_entry - finish allocation of 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 4bd6451..0592035 100644 --- a/fs/nilfs2/alloc.h +++ b/fs/nilfs2/alloc.h @@ -77,6 +77,7 @@ int nilfs_palloc_freev(struct inode *, __u64 *, size_t); #define nilfs_set_bit_atomic ext2_set_bit_atomic #define nilfs_clear_bit_atomic ext2_clear_bit_atomic #define nilfs_find_next_zero_bit find_next_zero_bit_le +#define nilfs_find_next_bit find_next_bit_le /** * struct nilfs_bh_assoc - block offset and buffer head association @@ -106,5 +107,10 @@ void nilfs_palloc_setup_cache(struct inode *inode, struct nilfs_palloc_cache *cache); void nilfs_palloc_clear_cache(struct inode *inode); void nilfs_palloc_destroy_cache(struct inode *inode); +int nilfs_palloc_scan_entries(struct inode *, + void (*dofunc)(struct inode *, + struct nilfs_palloc_req *, + void *), + void *); #endif /* _NILFS_ALLOC_H */ -- 1.9.0 -- 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
