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 <konishi.ryusuke@xxxxxxxxxxxxx>
---
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
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