2024-01-22 14:07:50

by Ryusuke Konishi

[permalink] [raw]
Subject: [PATCH 13/15] nilfs2: localize highmem mapping for checkpoint reading within cpfile

Move the code for reading from a checkpoint entry that is performed
in nilfs_attach_checkpoint() to the cpfile side, and make the page
mapping local and temporary. And use kmap_local instead of kmap
to access the checkpoint entry page.

In order to load the ifile inode information included in the checkpoint
entry within the inode lock section of nilfs_ifile_read(), the newly
added checkpoint reading method nilfs_cpfile_read_checkpoint() is called
indirectly via nilfs_ifile_read() instead of from
nilfs_attach_checkpoint().

Signed-off-by: Ryusuke Konishi <[email protected]>
---
fs/nilfs2/cpfile.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++
fs/nilfs2/cpfile.h | 2 ++
fs/nilfs2/ifile.c | 17 ++++++++----
fs/nilfs2/ifile.h | 3 +-
fs/nilfs2/super.c | 31 ++++-----------------
5 files changed, 87 insertions(+), 34 deletions(-)

diff --git a/fs/nilfs2/cpfile.c b/fs/nilfs2/cpfile.c
index 3af77252e081..56e38843536b 100644
--- a/fs/nilfs2/cpfile.c
+++ b/fs/nilfs2/cpfile.c
@@ -186,6 +186,74 @@ static inline int nilfs_cpfile_delete_checkpoint_block(struct inode *cpfile,
nilfs_cpfile_get_blkoff(cpfile, cno));
}

+/**
+ * nilfs_cpfile_read_checkpoint - read a checkpoint entry in cpfile
+ * @cpfile: checkpoint file inode
+ * @cno: number of checkpoint entry to read
+ * @root: nilfs root object
+ * @ifile: ifile's inode to read and attach to @root
+ *
+ * This function imports checkpoint information from the checkpoint file and
+ * stores it to the inode file given by @ifile and the nilfs root object
+ * given by @root.
+ *
+ * Return: 0 on success, or the following negative error code on failure.
+ * * %-EINVAL - Invalid checkpoint.
+ * * %-ENOMEM - Insufficient memory available.
+ * * %-EIO - I/O error (including metadata corruption).
+ */
+int nilfs_cpfile_read_checkpoint(struct inode *cpfile, __u64 cno,
+ struct nilfs_root *root, struct inode *ifile)
+{
+ struct buffer_head *cp_bh;
+ struct nilfs_checkpoint *cp;
+ void *kaddr;
+ int ret;
+
+ if (cno < 1 || cno > nilfs_mdt_cno(cpfile))
+ return -EINVAL;
+
+ down_read(&NILFS_MDT(cpfile)->mi_sem);
+ ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
+ if (unlikely(ret < 0)) {
+ if (ret == -ENOENT)
+ ret = -EINVAL;
+ goto out_sem;
+ }
+
+ kaddr = kmap_local_page(cp_bh->b_page);
+ cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
+ if (nilfs_checkpoint_invalid(cp)) {
+ ret = -EINVAL;
+ goto put_cp;
+ }
+
+ ret = nilfs_read_inode_common(ifile, &cp->cp_ifile_inode);
+ if (unlikely(ret)) {
+ /*
+ * Since this inode is on a checkpoint entry, treat errors
+ * as metadata corruption.
+ */
+ nilfs_err(cpfile->i_sb,
+ "ifile inode (checkpoint number=%llu) corrupted",
+ (unsigned long long)cno);
+ ret = -EIO;
+ goto put_cp;
+ }
+
+ /* Configure the nilfs root object */
+ atomic64_set(&root->inodes_count, le64_to_cpu(cp->cp_inodes_count));
+ atomic64_set(&root->blocks_count, le64_to_cpu(cp->cp_blocks_count));
+ root->ifile = ifile;
+
+put_cp:
+ kunmap_local(kaddr);
+ brelse(cp_bh);
+out_sem:
+ up_read(&NILFS_MDT(cpfile)->mi_sem);
+ return ret;
+}
+
/**
* nilfs_cpfile_get_checkpoint - get a checkpoint
* @cpfile: inode of checkpoint file
diff --git a/fs/nilfs2/cpfile.h b/fs/nilfs2/cpfile.h
index aa1408a3af01..2cfa14011bc8 100644
--- a/fs/nilfs2/cpfile.h
+++ b/fs/nilfs2/cpfile.h
@@ -19,6 +19,8 @@
int nilfs_cpfile_get_checkpoint(struct inode *, __u64, int,
struct nilfs_checkpoint **,
struct buffer_head **);
+int nilfs_cpfile_read_checkpoint(struct inode *cpfile, __u64 cno,
+ struct nilfs_root *root, struct inode *ifile);
int nilfs_cpfile_create_checkpoint(struct inode *cpfile, __u64 cno);
void nilfs_cpfile_put_checkpoint(struct inode *, __u64, struct buffer_head *);
int nilfs_cpfile_finalize_checkpoint(struct inode *cpfile, __u64 cno,
diff --git a/fs/nilfs2/ifile.c b/fs/nilfs2/ifile.c
index e9538fa46ff2..612e609158b5 100644
--- a/fs/nilfs2/ifile.c
+++ b/fs/nilfs2/ifile.c
@@ -15,6 +15,7 @@
#include "mdt.h"
#include "alloc.h"
#include "ifile.h"
+#include "cpfile.h"

/**
* struct nilfs_ifile_info - on-memory private data of ifile
@@ -173,14 +174,18 @@ int nilfs_ifile_count_free_inodes(struct inode *ifile,
* nilfs_ifile_read - read or get ifile inode
* @sb: super block instance
* @root: root object
+ * @cno: number of checkpoint entry to read
* @inode_size: size of an inode
- * @raw_inode: on-disk ifile inode
- * @inodep: buffer to store the inode
+ *
+ * Return: 0 on success, or the following negative error code on failure.
+ * * %-EINVAL - Invalid checkpoint.
+ * * %-ENOMEM - Insufficient memory available.
+ * * %-EIO - I/O error (including metadata corruption).
*/
int nilfs_ifile_read(struct super_block *sb, struct nilfs_root *root,
- size_t inode_size, struct nilfs_inode *raw_inode,
- struct inode **inodep)
+ __u64 cno, size_t inode_size)
{
+ struct the_nilfs *nilfs;
struct inode *ifile;
int err;

@@ -201,13 +206,13 @@ int nilfs_ifile_read(struct super_block *sb, struct nilfs_root *root,

nilfs_palloc_setup_cache(ifile, &NILFS_IFILE_I(ifile)->palloc_cache);

- err = nilfs_read_inode_common(ifile, raw_inode);
+ nilfs = sb->s_fs_info;
+ err = nilfs_cpfile_read_checkpoint(nilfs->ns_cpfile, cno, root, ifile);
if (err)
goto failed;

unlock_new_inode(ifile);
out:
- *inodep = ifile;
return 0;
failed:
iget_failed(ifile);
diff --git a/fs/nilfs2/ifile.h b/fs/nilfs2/ifile.h
index b71ab0a81dc4..625545cc2a98 100644
--- a/fs/nilfs2/ifile.h
+++ b/fs/nilfs2/ifile.h
@@ -38,7 +38,6 @@ int nilfs_ifile_get_inode_block(struct inode *, ino_t, struct buffer_head **);
int nilfs_ifile_count_free_inodes(struct inode *, u64 *, u64 *);

int nilfs_ifile_read(struct super_block *sb, struct nilfs_root *root,
- size_t inode_size, struct nilfs_inode *raw_inode,
- struct inode **inodep);
+ __u64 cno, size_t inode_size);

#endif /* _NILFS_IFILE_H */
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index df8674173b22..5e630c179a1e 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -544,8 +544,6 @@ int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
{
struct the_nilfs *nilfs = sb->s_fs_info;
struct nilfs_root *root;
- struct nilfs_checkpoint *raw_cp;
- struct buffer_head *bh_cp;
int err = -ENOMEM;

root = nilfs_find_or_create_root(
@@ -557,38 +555,19 @@ int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
goto reuse; /* already attached checkpoint */

down_read(&nilfs->ns_segctor_sem);
- err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, cno, 0, &raw_cp,
- &bh_cp);
+ err = nilfs_ifile_read(sb, root, cno, nilfs->ns_inode_size);
up_read(&nilfs->ns_segctor_sem);
- if (unlikely(err)) {
- if (err == -ENOENT || err == -EINVAL) {
- nilfs_err(sb,
- "Invalid checkpoint (checkpoint number=%llu)",
- (unsigned long long)cno);
- err = -EINVAL;
- }
+ if (unlikely(err))
goto failed;
- }
-
- err = nilfs_ifile_read(sb, root, nilfs->ns_inode_size,
- &raw_cp->cp_ifile_inode, &root->ifile);
- if (err)
- goto failed_bh;
-
- atomic64_set(&root->inodes_count,
- le64_to_cpu(raw_cp->cp_inodes_count));
- atomic64_set(&root->blocks_count,
- le64_to_cpu(raw_cp->cp_blocks_count));
-
- nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);

reuse:
*rootp = root;
return 0;

- failed_bh:
- nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, cno, bh_cp);
failed:
+ if (err == -EINVAL)
+ nilfs_err(sb, "Invalid checkpoint (checkpoint number=%llu)",
+ (unsigned long long)cno);
nilfs_put_root(root);

return err;
--
2.34.1