This adds a few routines to ifile, which are used to find out created, deleted, or modifed inodes between two versions of ifile, and enumerate the changes.
Signed-off-by: Ryusuke Konishi <[email protected]> --- fs/nilfs2/ifile.c | 184 +++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/nilfs2/ifile.h | 20 ++++++ 2 files changed, 204 insertions(+), 0 deletions(-) diff --git a/fs/nilfs2/ifile.c b/fs/nilfs2/ifile.c index 684d763..8980149 100644 --- a/fs/nilfs2/ifile.c +++ b/fs/nilfs2/ifile.c @@ -155,6 +155,190 @@ int nilfs_ifile_get_inode_block(struct inode *ifile, ino_t ino, return err; } +static ssize_t +nilfs_ifile_compare_block(struct inode *ifile1, struct inode *ifile2, + ino_t start, const struct nilfs_bmap_diff *diff, + struct nilfs_ifile_change *changes, + size_t maxchanges) +{ + struct buffer_head *ibh1 = NULL, *ibh2 = NULL; + struct nilfs_inode *raw_inode1, *raw_inode2; + void *kaddr1, *kaddr2; + size_t isz = NILFS_MDT(ifile1)->mi_entry_size; + __u64 nr; + ino_t ino, end; + int t; + int ret; + ssize_t n = 0; + + t = nilfs_palloc_block_type(ifile1, diff->key, &nr); + if (t != NILFS_PALLOC_ENTRY_BLOCK) + goto out; + + ino = max_t(ino_t, nr, start); + end = nr + NILFS_MDT(ifile1)->mi_entries_per_block - 1; + if (ino > end) + goto out; + + if (diff->ptr1 != NILFS_BMAP_INVALID_PTR) { + ret = nilfs_palloc_get_entry_block(ifile1, nr, 0, &ibh1); + if (ret < 0) { + WARN_ON(ret == -ENOENT); /* ifile is broken */ + n = ret; + goto out; + } + } + if (diff->ptr2 != NILFS_BMAP_INVALID_PTR) { + ret = nilfs_palloc_get_entry_block(ifile2, nr, 0, &ibh2); + if (ret < 0) { + WARN_ON(ret == -ENOENT); /* ifile is broken */ + n = ret; + brelse(ibh1); /* brelse(NULL) is ignored */ + goto out; + } + } + + if (!ibh1) { + if (!ibh2) + goto out_bh; + + kaddr2 = kmap_atomic(ibh2->b_page, KM_USER0); + raw_inode2 = nilfs_palloc_block_get_entry(ifile2, ino, ibh2, + kaddr2); + for ( ; ino <= end; ino++) { + if (le16_to_cpu(raw_inode2->i_links_count)) { + changes[n].ino = ino; + changes[n].bh1 = NULL; + get_bh(ibh2); + changes[n].bh2 = ibh2; + n++; + if (n == maxchanges) + break; + } + raw_inode2 = (void *)raw_inode2 + isz; + } + kunmap_atomic(kaddr2, KM_USER0); + + } else if (!ibh2) { + kaddr1 = kmap_atomic(ibh1->b_page, KM_USER0); + raw_inode1 = nilfs_palloc_block_get_entry(ifile1, ino, ibh1, + kaddr1); + for ( ; ino <= end; ino++) { + if (le16_to_cpu(raw_inode1->i_links_count)) { + changes[n].ino = ino; + get_bh(ibh1); + changes[n].bh1 = ibh1; + changes[n].bh2 = NULL; + n++; + if (n == maxchanges) + break; + } + raw_inode1 = (void *)raw_inode1 + isz; + } + kunmap_atomic(kaddr1, KM_USER0); + } else { + kaddr1 = kmap_atomic(ibh1->b_page, KM_USER0); + raw_inode1 = nilfs_palloc_block_get_entry(ifile1, ino, ibh1, + kaddr1); + kaddr2 = kmap_atomic(ibh2->b_page, KM_USER1); + raw_inode2 = nilfs_palloc_block_get_entry(ifile2, ino, ibh2, + kaddr2); + for (; ino <= end; ino++) { + if (raw_inode1->i_ctime_nsec != + raw_inode2->i_ctime_nsec || + raw_inode1->i_ctime != raw_inode2->i_ctime) { + changes[n].ino = ino; + if (le16_to_cpu(raw_inode1->i_links_count)) { + get_bh(ibh1); + changes[n].bh1 = ibh1; + } else { + changes[n].bh1 = NULL; + } + if (le16_to_cpu(raw_inode2->i_links_count)) { + get_bh(ibh2); + changes[n].bh2 = ibh2; + } else { + changes[n].bh2 = NULL; + } + n++; + if (n == maxchanges) + break; + } + raw_inode1 = (void *)raw_inode1 + isz; + raw_inode2 = (void *)raw_inode2 + isz; + } + kunmap_atomic(kaddr1, KM_USER0); + kunmap_atomic(kaddr2, KM_USER1); + } +out_bh: + brelse(ibh1); + brelse(ibh2); +out: + return n; +} + +/** + * nilfs_ifile_compare - compare two ifiles and find modified inodes + * @ifile1: source ifile inode + * @ifile2: target ifile inode + * @start: start inode number + * @changes: buffer to store nilfs_ifile_change structures + * @maxchanges: maximum number of changes that can be stored in @changes + */ +ssize_t nilfs_ifile_compare(struct inode *ifile1, struct inode *ifile2, + ino_t start, struct nilfs_ifile_change *changes, + size_t maxchanges) +{ + struct nilfs_bmap_diff *diffs; + __u64 blkoff; + size_t maxdiffs; + ssize_t nc = 0, nd, n; + int i; + + diffs = (struct nilfs_bmap_diff *)__get_free_pages(GFP_NOFS, 0); + if (unlikely(!diffs)) + return -ENOMEM; + + maxdiffs = PAGE_SIZE / sizeof(*diffs); + + blkoff = nilfs_palloc_entry_blkoff(ifile1, start); + + do { + nd = nilfs_bmap_compare(NILFS_I(ifile1)->i_bmap, + NILFS_I(ifile2)->i_bmap, + blkoff, diffs, maxdiffs); + if (nd < 0) { + nc = nd; + break; + } + if (nd == 0) + break; + for (i = 0; i < nd; i++) { + n = nilfs_ifile_compare_block( + ifile1, ifile2, start, &diffs[i], + &changes[nc], maxchanges - nc); + if (n < 0) { + nc = n; + goto failed; + } + nc += n; + if (nc == maxchanges) + goto out; + } + blkoff = diffs[i - 1].key + 1; + } while (nd == maxdiffs); +out: + free_pages((unsigned long)diffs, 0); + return nc; + +failed: + for (i = 0; i < nc; i++) { + brelse(changes[i].bh1); + brelse(changes[i].bh2); + } + goto out; +} + /** * nilfs_ifile_read - read or get ifile inode * @sb: super block instance diff --git a/fs/nilfs2/ifile.h b/fs/nilfs2/ifile.h index 59b6f2b..fe63ae8 100644 --- a/fs/nilfs2/ifile.h +++ b/fs/nilfs2/ifile.h @@ -32,6 +32,22 @@ #include "alloc.h" +/** + * struct nilfs_ifile_change - array item to store ifile comparison result + * @ino: inode number + * @bh1: pointers to buffer heads having source of changed disk inode + * @bh2: pointers to buffer heads having target of changed disk inode + * + * For new inodes, ptr array becomes @bh1 == NULL and @bh2 != NULL. + * For deleted inodes, ptr array becomes @bh1 != NULL and @bh2 == NULL. + * For modifed inodes, both @bh1 and @bh2 point to a valid item. + */ +struct nilfs_ifile_change { + ino_t ino; + struct buffer_head *bh1; + struct buffer_head *bh2; +}; + static inline struct nilfs_inode * nilfs_ifile_map_inode(struct inode *ifile, ino_t ino, struct buffer_head *ibh) { @@ -49,6 +65,10 @@ 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 **); +ssize_t nilfs_ifile_compare(struct inode *ifile1, struct inode *ifile2, + ino_t start, struct nilfs_ifile_change *buf, + size_t maxchanges); + int nilfs_ifile_read(struct super_block *sb, struct nilfs_root *root, size_t inode_size, struct nilfs_inode *raw_inode, struct inode **inodep); -- 1.7.3.5 -- 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
