nilfs2: implement resize ioctl
This adds resize ioctl which makes online resize possible.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index 6f61777..41d6743 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -698,6 +698,31 @@
return 0;
}
+static int nilfs_ioctl_resize(struct inode *inode, struct file *filp,
+ void __user *argp)
+{
+ __u64 newsize;
+ int ret = -EPERM;
+
+ if (!capable(CAP_SYS_ADMIN))
+ goto out;
+
+ ret = mnt_want_write(filp->f_path.mnt);
+ if (ret)
+ goto out;
+
+ ret = -EFAULT;
+ if (copy_from_user(&newsize, argp, sizeof(newsize)))
+ goto out_drop_write;
+
+ ret = nilfs_resize_fs(inode->i_sb, newsize);
+
+out_drop_write:
+ mnt_drop_write(filp->f_path.mnt);
+out:
+ return ret;
+}
+
static int nilfs_ioctl_set_alloc_range(struct inode *inode, void __user *argp)
{
struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
@@ -795,6 +820,8 @@
return nilfs_ioctl_clean_segments(inode, filp, cmd, argp);
case NILFS_IOCTL_SYNC:
return nilfs_ioctl_sync(inode, filp, cmd, argp);
+ case NILFS_IOCTL_RESIZE:
+ return nilfs_ioctl_resize(inode, filp, argp);
case NILFS_IOCTL_SET_ALLOC_RANGE:
return nilfs_ioctl_set_alloc_range(inode, argp);
default:
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index a8dd344..09af009 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -298,6 +298,7 @@
int flip);
int nilfs_commit_super(struct super_block *sb, int flag);
int nilfs_cleanup_super(struct super_block *sb);
+int nilfs_resize_fs(struct super_block *sb, __u64 newsize);
int nilfs_attach_checkpoint(struct super_block *sb, __u64 cno, int curr_mnt,
struct nilfs_root **root);
int nilfs_checkpoint_is_mounted(struct super_block *sb, __u64 cno);
diff --git a/fs/nilfs2/sufile.c b/fs/nilfs2/sufile.c
index 22f2e6e..37b9631 100644
--- a/fs/nilfs2/sufile.c
+++ b/fs/nilfs2/sufile.c
@@ -722,6 +722,73 @@
}
/**
+ * nilfs_sufile_resize - resize segment array
+ * @sufile: inode of segment usage file
+ * @newnsegs: new number of segments
+ *
+ * Return Value: On success, 0 is returned. On error, one of the
+ * following negative error codes is returned.
+ *
+ * %-EIO - I/O error.
+ *
+ * %-ENOMEM - Insufficient amount of memory available.
+ *
+ * %-ENOSPC - Enough free space is not left for shrinking
+ *
+ * %-EBUSY - Dirty or active segments exist in the region to be truncated
+ */
+int nilfs_sufile_resize(struct inode *sufile, __u64 newnsegs)
+{
+ struct the_nilfs *nilfs = sufile->i_sb->s_fs_info;
+ struct buffer_head *header_bh;
+ struct nilfs_sufile_header *header;
+ struct nilfs_sufile_info *sui = NILFS_SUI(sufile);
+ void *kaddr;
+ unsigned long nsegs, nrsvsegs;
+ int ret = 0;
+
+ down_write(&NILFS_MDT(sufile)->mi_sem);
+
+ nsegs = nilfs_sufile_get_nsegments(sufile);
+ if (nsegs == newnsegs)
+ goto out;
+
+ ret = -ENOSPC;
+ nrsvsegs = nilfs_nrsvsegs(nilfs, newnsegs);
+ if (newnsegs < nsegs && nsegs - newnsegs + nrsvsegs > sui->ncleansegs)
+ goto out;
+
+ ret = nilfs_sufile_get_header_block(sufile, &header_bh);
+ if (ret < 0)
+ goto out;
+
+ if (newnsegs > nsegs) {
+ sui->ncleansegs += newnsegs - nsegs;
+ } else /* newnsegs < nsegs */ {
+ ret = nilfs_sufile_truncate_range(sufile, newnsegs, nsegs - 1);
+ if (ret < 0)
+ goto out_header;
+
+ sui->ncleansegs -= nsegs - newnsegs;
+ }
+
+ kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
+ header = kaddr + bh_offset(header_bh);
+ header->sh_ncleansegs = cpu_to_le64(sui->ncleansegs);
+ kunmap_atomic(kaddr, KM_USER0);
+
+ nilfs_mdt_mark_buffer_dirty(header_bh);
+ nilfs_mdt_mark_dirty(sufile);
+ nilfs_set_nsegments(nilfs, newnsegs);
+
+out_header:
+ brelse(header_bh);
+out:
+ up_write(&NILFS_MDT(sufile)->mi_sem);
+ return ret;
+}
+
+/**
* nilfs_sufile_get_suinfo -
* @sufile: inode of segment usage file
* @segnum: segment number to start looking
diff --git a/fs/nilfs2/sufile.h b/fs/nilfs2/sufile.h
index 57bfee9..1eac4c6 100644
--- a/fs/nilfs2/sufile.h
+++ b/fs/nilfs2/sufile.h
@@ -62,6 +62,7 @@
void nilfs_sufile_do_set_error(struct inode *, __u64, struct buffer_head *,
struct buffer_head *);
+int nilfs_sufile_resize(struct inode *sufile, __u64 newnsegs);
int nilfs_sufile_read(struct super_block *sb, size_t susize,
struct nilfs_inode *raw_inode, struct inode **inodep);
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index eba5b53..2846491 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -56,6 +56,7 @@
#include "btnode.h"
#include "page.h"
#include "cpfile.h"
+#include "sufile.h" /* nilfs_sufile_resize(), nilfs_sufile_set_alloc_range() */
#include "ifile.h"
#include "dat.h"
#include "segment.h"
@@ -404,6 +405,77 @@
return ret;
}
+/**
+ * nilfs_resize_fs - resize the filesystem
+ * @sb: super block instance
+ * @newsize: new size of the filesystem (in bytes)
+ */
+int nilfs_resize_fs(struct super_block *sb, __u64 newsize)
+{
+ struct the_nilfs *nilfs = sb->s_fs_info;
+ struct nilfs_super_block **sbp;
+ __u64 devsize, newnsegs;
+ loff_t sb2off;
+ int ret;
+
+ ret = -ERANGE;
+ devsize = i_size_read(sb->s_bdev->bd_inode);
+ if (newsize > devsize)
+ goto out;
+
+ /*
+ * Write lock is required to protect some functions depending
+ * on the number of segments, the number of reserved segments,
+ * and so forth.
+ */
+ down_write(&nilfs->ns_segctor_sem);
+
+ sb2off = NILFS_SB2_OFFSET_BYTES(newsize);
+ newnsegs = sb2off >> nilfs->ns_blocksize_bits;
+ do_div(newnsegs, nilfs->ns_blocks_per_segment);
+
+ ret = nilfs_sufile_resize(nilfs->ns_sufile, newnsegs);
+ up_write(&nilfs->ns_segctor_sem);
+ if (ret < 0)
+ goto out;
+
+ ret = nilfs_construct_segment(sb);
+ if (ret < 0)
+ goto out;
+
+ down_write(&nilfs->ns_sem);
+ nilfs_move_2nd_super(sb, sb2off);
+ ret = -EIO;
+ sbp = nilfs_prepare_super(sb, 0);
+ if (likely(sbp)) {
+ nilfs_set_log_cursor(sbp[0], nilfs);
+ /*
+ * Drop NILFS_RESIZE_FS flag for compatibility with
+ * mount-time resize which may be implemented in a
+ * future release.
+ */
+ sbp[0]->s_state = cpu_to_le16(le16_to_cpu(sbp[0]->s_state) &
+ ~NILFS_RESIZE_FS);
+ sbp[0]->s_dev_size = cpu_to_le64(newsize);
+ sbp[0]->s_nsegments = cpu_to_le64(nilfs->ns_nsegments);
+ if (sbp[1])
+ memcpy(sbp[1], sbp[0], nilfs->ns_sbsize);
+ ret = nilfs_commit_super(sb, NILFS_SB_COMMIT_ALL);
+ }
+ up_write(&nilfs->ns_sem);
+
+ /*
+ * Reset the range of allocatable segments last. This order
+ * is important in the case of expansion because the secondary
+ * superblock must be protected from log write until migration
+ * completes.
+ */
+ if (!ret)
+ nilfs_sufile_set_alloc_range(nilfs->ns_sufile, 0, newnsegs - 1);
+out:
+ return ret;
+}
+
static void nilfs_put_super(struct super_block *sb)
{
struct the_nilfs *nilfs = sb->s_fs_info;
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index d2acd1a..d327140 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -363,6 +363,24 @@
return res;
}
+/**
+ * nilfs_nrsvsegs - calculate the number of reserved segments
+ * @nilfs: nilfs object
+ * @nsegs: total number of segments
+ */
+unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs)
+{
+ return max_t(unsigned long, NILFS_MIN_NRSVSEGS,
+ DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage,
+ 100));
+}
+
+void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
+{
+ nilfs->ns_nsegments = nsegs;
+ nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
+}
+
static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
struct nilfs_super_block *sbp)
{
@@ -389,13 +407,9 @@
}
nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
- nilfs->ns_nsegments = le64_to_cpu(sbp->s_nsegments);
nilfs->ns_r_segments_percentage =
le32_to_cpu(sbp->s_r_segments_percentage);
- nilfs->ns_nrsvsegs =
- max_t(unsigned long, NILFS_MIN_NRSVSEGS,
- DIV_ROUND_UP(nilfs->ns_nsegments *
- nilfs->ns_r_segments_percentage, 100));
+ nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments));
nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
return 0;
}
diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index f496814..9992b11 100644
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -268,6 +268,8 @@
void destroy_nilfs(struct the_nilfs *nilfs);
int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data);
int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb);
+unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs);
+void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs);
int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t);
int nilfs_count_free_blocks(struct the_nilfs *, sector_t *);
struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno);