Regarding the persistent oject allocator, a common mechanism for
allocating objects in metadata files such as inodes and DAT entries,
convert the page-based implementation to a folio-based implementation.
In this conversion, helper functions nilfs_palloc_group_desc_offset()
and nilfs_palloc_bitmap_offset() are added and used to calculate the
byte offset within a folio of a group descriptor structure and bitmap,
respectively, to replace kmap_local_page with kmap_local_folio.
In addition, a helper function called nilfs_palloc_entry_offset() is
provided to facilitate common calculation of the byte offset within a
folio of metadata file entries managed in the persistent object
allocator format.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
fs/nilfs2/alloc.c | 137 +++++++++++++++++++++++++++++-----------------
fs/nilfs2/alloc.h | 2 +
2 files changed, 89 insertions(+), 50 deletions(-)
diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c
index d30dfed707b6..5e0a6bd3e015 100644
--- a/fs/nilfs2/alloc.c
+++ b/fs/nilfs2/alloc.c
@@ -339,19 +339,55 @@ static int nilfs_palloc_delete_entry_block(struct inode *inode, __u64 nr)
}
/**
- * nilfs_palloc_block_get_group_desc - get kernel address of a group descriptor
+ * nilfs_palloc_group_desc_offset - calculate the byte offset of a group
+ * descriptor in the folio containing it
* @inode: inode of metadata file using this allocator
* @group: group number
- * @bh: buffer head of the buffer storing the group descriptor block
- * @kaddr: kernel address mapped for the page including the buffer
+ * @bh: buffer head of the group descriptor block
+ *
+ * Return: Byte offset in the folio of the group descriptor for @group.
*/
-static struct nilfs_palloc_group_desc *
-nilfs_palloc_block_get_group_desc(const struct inode *inode,
- unsigned long group,
- const struct buffer_head *bh, void *kaddr)
+static size_t nilfs_palloc_group_desc_offset(const struct inode *inode,
+ unsigned long group,
+ const struct buffer_head *bh)
{
- return (struct nilfs_palloc_group_desc *)(kaddr + bh_offset(bh)) +
- group % nilfs_palloc_groups_per_desc_block(inode);
+ return offset_in_folio(bh->b_folio, bh->b_data) +
+ sizeof(struct nilfs_palloc_group_desc) *
+ (group % nilfs_palloc_groups_per_desc_block(inode));
+}
+
+/**
+ * nilfs_palloc_bitmap_offset - calculate the byte offset of a bitmap block
+ * in the folio containing it
+ * @bh: buffer head of the bitmap block
+ *
+ * Return: Byte offset in the folio of the bitmap block for @bh.
+ */
+static size_t nilfs_palloc_bitmap_offset(const struct buffer_head *bh)
+{
+ return offset_in_folio(bh->b_folio, bh->b_data);
+}
+
+/**
+ * nilfs_palloc_entry_offset - calculate the byte offset of an entry in the
+ * folio containing it
+ * @inode: inode of metadata file using this allocator
+ * @nr: serial number of the entry (e.g. inode number)
+ * @bh: buffer head of the entry block
+ *
+ * Return: Byte offset in the folio of the entry @nr.
+ */
+size_t nilfs_palloc_entry_offset(const struct inode *inode, __u64 nr,
+ const struct buffer_head *bh)
+{
+ unsigned long entry_index_in_group, entry_index_in_block;
+
+ nilfs_palloc_group(inode, nr, &entry_index_in_group);
+ entry_index_in_block = entry_index_in_group %
+ NILFS_MDT(inode)->mi_entries_per_block;
+
+ return offset_in_folio(bh->b_folio, bh->b_data) +
+ entry_index_in_block * NILFS_MDT(inode)->mi_entry_size;
}
/**
@@ -508,7 +544,7 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
struct buffer_head *desc_bh, *bitmap_bh;
struct nilfs_palloc_group_desc *desc;
unsigned char *bitmap;
- void *desc_kaddr, *bitmap_kaddr;
+ size_t doff, boff;
unsigned long group, maxgroup, ngroups;
unsigned long group_offset, maxgroup_offset;
unsigned long n, entries_per_group;
@@ -531,17 +567,17 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
if (ret < 0)
return ret;
- desc_kaddr = kmap_local_page(desc_bh->b_page);
- desc = nilfs_palloc_block_get_group_desc(
- inode, group, desc_bh, desc_kaddr);
+
+ doff = nilfs_palloc_group_desc_offset(inode, group, desc_bh);
+ desc = kmap_local_folio(desc_bh->b_folio, doff);
n = nilfs_palloc_rest_groups_in_desc_block(inode, group,
maxgroup);
- for (j = 0; j < n; j++, desc++, group++, group_offset = 0) {
+ for (j = 0; j < n; j++, group++, group_offset = 0) {
lock = nilfs_mdt_bgl_lock(inode, group);
- if (nilfs_palloc_group_desc_nfrees(desc, lock) == 0)
+ if (nilfs_palloc_group_desc_nfrees(&desc[j], lock) == 0)
continue;
- kunmap_local(desc_kaddr);
+ kunmap_local(desc);
ret = nilfs_palloc_get_bitmap_block(inode, group, 1,
&bitmap_bh);
if (unlikely(ret < 0)) {
@@ -549,12 +585,14 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
return ret;
}
- desc_kaddr = kmap_local_page(desc_bh->b_page);
- desc = nilfs_palloc_block_get_group_desc(
- inode, group, desc_bh, desc_kaddr);
+ /*
+ * Re-kmap the folio containing the first (and
+ * subsequent) group descriptors.
+ */
+ desc = kmap_local_folio(desc_bh->b_folio, doff);
- bitmap_kaddr = kmap_local_page(bitmap_bh->b_page);
- bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
+ boff = nilfs_palloc_bitmap_offset(bitmap_bh);
+ bitmap = kmap_local_folio(bitmap_bh->b_folio, boff);
pos = nilfs_palloc_find_available_slot(
bitmap, group_offset, entries_per_group, lock,
wrap);
@@ -564,14 +602,14 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
* beginning, the wrap flag only has an effect on the
* first search.
*/
- kunmap_local(bitmap_kaddr);
+ kunmap_local(bitmap);
if (pos >= 0)
goto found;
brelse(bitmap_bh);
}
- kunmap_local(desc_kaddr);
+ kunmap_local(desc);
brelse(desc_bh);
}
@@ -580,9 +618,9 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
found:
/* found a free entry */
- nilfs_palloc_group_desc_add_entries(desc, lock, -1);
+ nilfs_palloc_group_desc_add_entries(&desc[j], lock, -1);
req->pr_entry_nr = entries_per_group * group + pos;
- kunmap_local(desc_kaddr);
+ kunmap_local(desc);
req->pr_desc_bh = desc_bh;
req->pr_bitmap_bh = bitmap_bh;
@@ -613,18 +651,18 @@ void nilfs_palloc_commit_alloc_entry(struct inode *inode,
void nilfs_palloc_commit_free_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
- struct nilfs_palloc_group_desc *desc;
unsigned long group, group_offset;
+ size_t doff, boff;
+ struct nilfs_palloc_group_desc *desc;
unsigned char *bitmap;
- void *desc_kaddr, *bitmap_kaddr;
spinlock_t *lock;
group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
- desc_kaddr = kmap_local_page(req->pr_desc_bh->b_page);
- desc = nilfs_palloc_block_get_group_desc(inode, group,
- req->pr_desc_bh, desc_kaddr);
- bitmap_kaddr = kmap_local_page(req->pr_bitmap_bh->b_page);
- bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
+ doff = nilfs_palloc_group_desc_offset(inode, group, req->pr_desc_bh);
+ desc = kmap_local_folio(req->pr_desc_bh->b_folio, doff);
+
+ boff = nilfs_palloc_bitmap_offset(req->pr_bitmap_bh);
+ bitmap = kmap_local_folio(req->pr_bitmap_bh->b_folio, boff);
lock = nilfs_mdt_bgl_lock(inode, group);
if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))
@@ -635,8 +673,8 @@ void nilfs_palloc_commit_free_entry(struct inode *inode,
else
nilfs_palloc_group_desc_add_entries(desc, lock, 1);
- kunmap_local(bitmap_kaddr);
- kunmap_local(desc_kaddr);
+ kunmap_local(bitmap);
+ kunmap_local(desc);
mark_buffer_dirty(req->pr_desc_bh);
mark_buffer_dirty(req->pr_bitmap_bh);
@@ -655,17 +693,17 @@ void nilfs_palloc_abort_alloc_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
struct nilfs_palloc_group_desc *desc;
- void *desc_kaddr, *bitmap_kaddr;
+ size_t doff, boff;
unsigned char *bitmap;
unsigned long group, group_offset;
spinlock_t *lock;
group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
- desc_kaddr = kmap_local_page(req->pr_desc_bh->b_page);
- desc = nilfs_palloc_block_get_group_desc(inode, group,
- req->pr_desc_bh, desc_kaddr);
- bitmap_kaddr = kmap_local_page(req->pr_bitmap_bh->b_page);
- bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
+ doff = nilfs_palloc_group_desc_offset(inode, group, req->pr_desc_bh);
+ desc = kmap_local_folio(req->pr_desc_bh->b_folio, doff);
+
+ boff = nilfs_palloc_bitmap_offset(req->pr_bitmap_bh);
+ bitmap = kmap_local_folio(req->pr_bitmap_bh->b_folio, boff);
lock = nilfs_mdt_bgl_lock(inode, group);
if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))
@@ -676,8 +714,8 @@ void nilfs_palloc_abort_alloc_entry(struct inode *inode,
else
nilfs_palloc_group_desc_add_entries(desc, lock, 1);
- kunmap_local(bitmap_kaddr);
- kunmap_local(desc_kaddr);
+ kunmap_local(bitmap);
+ kunmap_local(desc);
brelse(req->pr_bitmap_bh);
brelse(req->pr_desc_bh);
@@ -741,7 +779,7 @@ int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
struct buffer_head *desc_bh, *bitmap_bh;
struct nilfs_palloc_group_desc *desc;
unsigned char *bitmap;
- void *desc_kaddr, *bitmap_kaddr;
+ size_t doff, boff;
unsigned long group, group_offset;
__u64 group_min_nr, last_nrs[8];
const unsigned long epg = nilfs_palloc_entries_per_group(inode);
@@ -769,8 +807,8 @@ int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
/* Get the first entry number of the group */
group_min_nr = (__u64)group * epg;
- bitmap_kaddr = kmap_local_page(bitmap_bh->b_page);
- bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
+ boff = nilfs_palloc_bitmap_offset(bitmap_bh);
+ bitmap = kmap_local_folio(bitmap_bh->b_folio, boff);
lock = nilfs_mdt_bgl_lock(inode, group);
j = i;
@@ -815,7 +853,7 @@ int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
entry_start = rounddown(group_offset, epb);
} while (true);
- kunmap_local(bitmap_kaddr);
+ kunmap_local(bitmap);
mark_buffer_dirty(bitmap_bh);
brelse(bitmap_bh);
@@ -829,11 +867,10 @@ int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
inode->i_ino);
}
- desc_kaddr = kmap_local_page(desc_bh->b_page);
- desc = nilfs_palloc_block_get_group_desc(
- inode, group, desc_bh, desc_kaddr);
+ doff = nilfs_palloc_group_desc_offset(inode, group, desc_bh);
+ desc = kmap_local_folio(desc_bh->b_folio, doff);
nfree = nilfs_palloc_group_desc_add_entries(desc, lock, n);
- kunmap_local(desc_kaddr);
+ kunmap_local(desc);
mark_buffer_dirty(desc_bh);
nilfs_mdt_mark_dirty(inode);
brelse(desc_bh);
diff --git a/fs/nilfs2/alloc.h b/fs/nilfs2/alloc.h
index e19d7eb10084..af8f882619d4 100644
--- a/fs/nilfs2/alloc.h
+++ b/fs/nilfs2/alloc.h
@@ -33,6 +33,8 @@ int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
struct buffer_head **);
void *nilfs_palloc_block_get_entry(const struct inode *, __u64,
const struct buffer_head *, void *);
+size_t nilfs_palloc_entry_offset(const struct inode *inode, __u64 nr,
+ const struct buffer_head *bh);
int nilfs_palloc_count_max_entries(struct inode *, u64, u64 *);
--
2.43.0
