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6c98cd4ecb
This adds a meta data file which stores the allocation state of segments. [konishi.ryusuke@lab.ntt.co.jp: fix wrong counting of checkpoints and dirty segments] Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
909 lines
24 KiB
C
909 lines
24 KiB
C
/*
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* cpfile.c - NILFS checkpoint file.
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*
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* Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Written by Koji Sato <koji@osrg.net>.
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*/
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/string.h>
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#include <linux/buffer_head.h>
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#include <linux/errno.h>
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#include <linux/nilfs2_fs.h>
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#include "mdt.h"
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#include "cpfile.h"
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static inline unsigned long
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nilfs_cpfile_checkpoints_per_block(const struct inode *cpfile)
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{
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return NILFS_MDT(cpfile)->mi_entries_per_block;
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}
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/* block number from the beginning of the file */
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static unsigned long
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nilfs_cpfile_get_blkoff(const struct inode *cpfile, __u64 cno)
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{
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__u64 tcno;
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BUG_ON(cno == 0); /* checkpoint number 0 is invalid */
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tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1;
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do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile));
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return (unsigned long)tcno;
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}
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/* offset in block */
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static unsigned long
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nilfs_cpfile_get_offset(const struct inode *cpfile, __u64 cno)
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{
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__u64 tcno = cno + NILFS_MDT(cpfile)->mi_first_entry_offset - 1;
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return do_div(tcno, nilfs_cpfile_checkpoints_per_block(cpfile));
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}
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static unsigned long
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nilfs_cpfile_checkpoints_in_block(const struct inode *cpfile,
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__u64 curr,
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__u64 max)
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{
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return min_t(__u64,
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nilfs_cpfile_checkpoints_per_block(cpfile) -
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nilfs_cpfile_get_offset(cpfile, curr),
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max - curr);
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}
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static inline int nilfs_cpfile_is_in_first(const struct inode *cpfile,
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__u64 cno)
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{
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return nilfs_cpfile_get_blkoff(cpfile, cno) == 0;
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}
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static unsigned int
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nilfs_cpfile_block_add_valid_checkpoints(const struct inode *cpfile,
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struct buffer_head *bh,
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void *kaddr,
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unsigned int n)
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{
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struct nilfs_checkpoint *cp = kaddr + bh_offset(bh);
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unsigned int count;
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count = le32_to_cpu(cp->cp_checkpoints_count) + n;
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cp->cp_checkpoints_count = cpu_to_le32(count);
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return count;
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}
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static unsigned int
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nilfs_cpfile_block_sub_valid_checkpoints(const struct inode *cpfile,
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struct buffer_head *bh,
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void *kaddr,
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unsigned int n)
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{
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struct nilfs_checkpoint *cp = kaddr + bh_offset(bh);
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unsigned int count;
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BUG_ON(le32_to_cpu(cp->cp_checkpoints_count) < n);
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count = le32_to_cpu(cp->cp_checkpoints_count) - n;
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cp->cp_checkpoints_count = cpu_to_le32(count);
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return count;
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}
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static inline struct nilfs_cpfile_header *
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nilfs_cpfile_block_get_header(const struct inode *cpfile,
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struct buffer_head *bh,
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void *kaddr)
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{
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return kaddr + bh_offset(bh);
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}
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static struct nilfs_checkpoint *
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nilfs_cpfile_block_get_checkpoint(const struct inode *cpfile, __u64 cno,
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struct buffer_head *bh,
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void *kaddr)
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{
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return kaddr + bh_offset(bh) + nilfs_cpfile_get_offset(cpfile, cno) *
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NILFS_MDT(cpfile)->mi_entry_size;
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}
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static void nilfs_cpfile_block_init(struct inode *cpfile,
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struct buffer_head *bh,
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void *kaddr)
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{
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struct nilfs_checkpoint *cp = kaddr + bh_offset(bh);
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size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
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int n = nilfs_cpfile_checkpoints_per_block(cpfile);
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while (n-- > 0) {
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nilfs_checkpoint_set_invalid(cp);
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cp = (void *)cp + cpsz;
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}
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}
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static inline int nilfs_cpfile_get_header_block(struct inode *cpfile,
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struct buffer_head **bhp)
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{
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return nilfs_mdt_get_block(cpfile, 0, 0, NULL, bhp);
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}
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static inline int nilfs_cpfile_get_checkpoint_block(struct inode *cpfile,
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__u64 cno,
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int create,
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struct buffer_head **bhp)
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{
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return nilfs_mdt_get_block(cpfile,
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nilfs_cpfile_get_blkoff(cpfile, cno),
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create, nilfs_cpfile_block_init, bhp);
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}
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static inline int nilfs_cpfile_delete_checkpoint_block(struct inode *cpfile,
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__u64 cno)
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{
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return nilfs_mdt_delete_block(cpfile,
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nilfs_cpfile_get_blkoff(cpfile, cno));
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}
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/**
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* nilfs_cpfile_get_checkpoint - get a checkpoint
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* @cpfile: inode of checkpoint file
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* @cno: checkpoint number
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* @create: create flag
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* @cpp: pointer to a checkpoint
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* @bhp: pointer to a buffer head
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*
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* Description: nilfs_cpfile_get_checkpoint() acquires the checkpoint
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* specified by @cno. A new checkpoint will be created if @cno is the current
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* checkpoint number and @create is nonzero.
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*
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* Return Value: On success, 0 is returned, and the checkpoint and the
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* buffer head of the buffer on which the checkpoint is located are stored in
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* the place pointed by @cpp and @bhp, respectively. On error, one of the
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* following negative error codes is returned.
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*
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* %-EIO - I/O error.
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*
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* %-ENOMEM - Insufficient amount of memory available.
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*
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* %-ENOENT - No such checkpoint.
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*/
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int nilfs_cpfile_get_checkpoint(struct inode *cpfile,
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__u64 cno,
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int create,
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struct nilfs_checkpoint **cpp,
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struct buffer_head **bhp)
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{
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struct buffer_head *header_bh, *cp_bh;
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struct nilfs_cpfile_header *header;
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struct nilfs_checkpoint *cp;
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void *kaddr;
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int ret;
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BUG_ON(cno < 1 || cno > nilfs_mdt_cno(cpfile) ||
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(cno < nilfs_mdt_cno(cpfile) && create));
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down_write(&NILFS_MDT(cpfile)->mi_sem);
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ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
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if (ret < 0)
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goto out_sem;
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ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create, &cp_bh);
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if (ret < 0)
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goto out_header;
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kaddr = kmap(cp_bh->b_page);
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cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
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if (nilfs_checkpoint_invalid(cp)) {
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if (!create) {
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kunmap(cp_bh->b_page);
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brelse(cp_bh);
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ret = -ENOENT;
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goto out_header;
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}
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/* a newly-created checkpoint */
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nilfs_checkpoint_clear_invalid(cp);
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if (!nilfs_cpfile_is_in_first(cpfile, cno))
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nilfs_cpfile_block_add_valid_checkpoints(cpfile, cp_bh,
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kaddr, 1);
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nilfs_mdt_mark_buffer_dirty(cp_bh);
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kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
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header = nilfs_cpfile_block_get_header(cpfile, header_bh,
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kaddr);
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le64_add_cpu(&header->ch_ncheckpoints, 1);
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kunmap_atomic(kaddr, KM_USER0);
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nilfs_mdt_mark_buffer_dirty(header_bh);
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nilfs_mdt_mark_dirty(cpfile);
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}
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if (cpp != NULL)
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*cpp = cp;
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*bhp = cp_bh;
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out_header:
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brelse(header_bh);
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out_sem:
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up_write(&NILFS_MDT(cpfile)->mi_sem);
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return ret;
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}
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/**
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* nilfs_cpfile_put_checkpoint - put a checkpoint
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* @cpfile: inode of checkpoint file
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* @cno: checkpoint number
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* @bh: buffer head
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*
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* Description: nilfs_cpfile_put_checkpoint() releases the checkpoint
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* specified by @cno. @bh must be the buffer head which has been returned by
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* a previous call to nilfs_cpfile_get_checkpoint() with @cno.
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*/
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void nilfs_cpfile_put_checkpoint(struct inode *cpfile, __u64 cno,
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struct buffer_head *bh)
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{
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kunmap(bh->b_page);
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brelse(bh);
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}
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/**
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* nilfs_cpfile_delete_checkpoints - delete checkpoints
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* @cpfile: inode of checkpoint file
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* @start: start checkpoint number
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* @end: end checkpoint numer
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*
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* Description: nilfs_cpfile_delete_checkpoints() deletes the checkpoints in
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* the period from @start to @end, excluding @end itself. The checkpoints
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* which have been already deleted are ignored.
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*
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* Return Value: On success, 0 is returned. On error, one of the following
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* negative error codes is returned.
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*
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* %-EIO - I/O error.
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*
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* %-ENOMEM - Insufficient amount of memory available.
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*
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* %-EINVAL - invalid checkpoints.
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*/
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int nilfs_cpfile_delete_checkpoints(struct inode *cpfile,
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__u64 start,
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__u64 end)
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{
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struct buffer_head *header_bh, *cp_bh;
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struct nilfs_cpfile_header *header;
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struct nilfs_checkpoint *cp;
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size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
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__u64 cno;
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void *kaddr;
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unsigned long tnicps;
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int ret, ncps, nicps, count, i;
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if ((start == 0) || (start > end)) {
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printk(KERN_CRIT "%s: start = %llu, end = %llu\n",
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__func__,
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(unsigned long long)start,
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(unsigned long long)end);
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BUG();
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}
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/* cannot delete the latest checkpoint */
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if (start == nilfs_mdt_cno(cpfile) - 1)
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return -EPERM;
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down_write(&NILFS_MDT(cpfile)->mi_sem);
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ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
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if (ret < 0)
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goto out_sem;
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tnicps = 0;
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for (cno = start; cno < end; cno += ncps) {
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ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, end);
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ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
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if (ret < 0) {
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if (ret != -ENOENT)
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goto out_sem;
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/* skip hole */
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ret = 0;
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continue;
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}
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kaddr = kmap_atomic(cp_bh->b_page, KM_USER0);
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cp = nilfs_cpfile_block_get_checkpoint(
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cpfile, cno, cp_bh, kaddr);
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nicps = 0;
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for (i = 0; i < ncps; i++, cp = (void *)cp + cpsz) {
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BUG_ON(nilfs_checkpoint_snapshot(cp));
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if (!nilfs_checkpoint_invalid(cp)) {
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nilfs_checkpoint_set_invalid(cp);
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nicps++;
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}
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}
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if (nicps > 0) {
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tnicps += nicps;
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nilfs_mdt_mark_buffer_dirty(cp_bh);
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nilfs_mdt_mark_dirty(cpfile);
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if (!nilfs_cpfile_is_in_first(cpfile, cno) &&
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(count = nilfs_cpfile_block_sub_valid_checkpoints(
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cpfile, cp_bh, kaddr, nicps)) == 0) {
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/* make hole */
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kunmap_atomic(kaddr, KM_USER0);
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brelse(cp_bh);
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ret = nilfs_cpfile_delete_checkpoint_block(
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cpfile, cno);
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if (ret == 0)
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continue;
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printk(KERN_ERR "%s: cannot delete block\n",
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__func__);
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goto out_sem;
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}
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}
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kunmap_atomic(kaddr, KM_USER0);
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brelse(cp_bh);
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}
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if (tnicps > 0) {
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kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
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header = nilfs_cpfile_block_get_header(cpfile, header_bh,
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kaddr);
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le64_add_cpu(&header->ch_ncheckpoints, -(u64)tnicps);
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nilfs_mdt_mark_buffer_dirty(header_bh);
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nilfs_mdt_mark_dirty(cpfile);
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kunmap_atomic(kaddr, KM_USER0);
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}
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brelse(header_bh);
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out_sem:
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up_write(&NILFS_MDT(cpfile)->mi_sem);
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return ret;
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}
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static void nilfs_cpfile_checkpoint_to_cpinfo(struct inode *cpfile,
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struct nilfs_checkpoint *cp,
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struct nilfs_cpinfo *ci)
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{
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ci->ci_flags = le32_to_cpu(cp->cp_flags);
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ci->ci_cno = le64_to_cpu(cp->cp_cno);
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ci->ci_create = le64_to_cpu(cp->cp_create);
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ci->ci_nblk_inc = le64_to_cpu(cp->cp_nblk_inc);
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ci->ci_inodes_count = le64_to_cpu(cp->cp_inodes_count);
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ci->ci_blocks_count = le64_to_cpu(cp->cp_blocks_count);
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ci->ci_next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
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}
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static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 cno,
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struct nilfs_cpinfo *ci, size_t nci)
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{
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struct nilfs_checkpoint *cp;
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struct buffer_head *bh;
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size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;
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__u64 cur_cno = nilfs_mdt_cno(cpfile);
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void *kaddr;
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int n, ret;
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int ncps, i;
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down_read(&NILFS_MDT(cpfile)->mi_sem);
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for (n = 0; cno < cur_cno && n < nci; cno += ncps) {
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ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno);
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ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh);
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if (ret < 0) {
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if (ret != -ENOENT)
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goto out;
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continue; /* skip hole */
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}
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kaddr = kmap_atomic(bh->b_page, KM_USER0);
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cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
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for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) {
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if (!nilfs_checkpoint_invalid(cp))
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nilfs_cpfile_checkpoint_to_cpinfo(
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cpfile, cp, &ci[n++]);
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}
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kunmap_atomic(kaddr, KM_USER0);
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brelse(bh);
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}
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ret = n;
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out:
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up_read(&NILFS_MDT(cpfile)->mi_sem);
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return ret;
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}
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static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 cno,
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struct nilfs_cpinfo *ci, size_t nci)
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{
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struct buffer_head *bh;
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struct nilfs_cpfile_header *header;
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struct nilfs_checkpoint *cp;
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__u64 curr, next;
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unsigned long curr_blkoff, next_blkoff;
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void *kaddr;
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int n, ret;
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down_read(&NILFS_MDT(cpfile)->mi_sem);
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if (cno == 0) {
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ret = nilfs_cpfile_get_header_block(cpfile, &bh);
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if (ret < 0)
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goto out;
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kaddr = kmap_atomic(bh->b_page, KM_USER0);
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header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
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curr = le64_to_cpu(header->ch_snapshot_list.ssl_next);
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kunmap_atomic(kaddr, KM_USER0);
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brelse(bh);
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if (curr == 0) {
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ret = 0;
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goto out;
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}
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} else
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curr = cno;
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curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr);
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ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh);
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if (ret < 0)
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goto out;
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kaddr = kmap_atomic(bh->b_page, KM_USER0);
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for (n = 0; n < nci; n++) {
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cp = nilfs_cpfile_block_get_checkpoint(
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cpfile, curr, bh, kaddr);
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nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, &ci[n]);
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next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);
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if (next == 0) {
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curr = next;
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n++;
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break;
|
|
}
|
|
next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next);
|
|
if (curr_blkoff != next_blkoff) {
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
brelse(bh);
|
|
ret = nilfs_cpfile_get_checkpoint_block(cpfile, next,
|
|
0, &bh);
|
|
if (ret < 0)
|
|
goto out;
|
|
kaddr = kmap_atomic(bh->b_page, KM_USER0);
|
|
}
|
|
curr = next;
|
|
curr_blkoff = next_blkoff;
|
|
}
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
brelse(bh);
|
|
ret = n;
|
|
|
|
out:
|
|
up_read(&NILFS_MDT(cpfile)->mi_sem);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* nilfs_cpfile_get_cpinfo -
|
|
* @cpfile:
|
|
* @cno:
|
|
* @ci:
|
|
* @nci:
|
|
*/
|
|
ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile,
|
|
__u64 cno, int mode,
|
|
struct nilfs_cpinfo *ci, size_t nci)
|
|
{
|
|
switch (mode) {
|
|
case NILFS_CHECKPOINT:
|
|
return nilfs_cpfile_do_get_cpinfo(cpfile, cno, ci, nci);
|
|
case NILFS_SNAPSHOT:
|
|
return nilfs_cpfile_do_get_ssinfo(cpfile, cno, ci, nci);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* nilfs_cpfile_delete_checkpoint -
|
|
* @cpfile:
|
|
* @cno:
|
|
*/
|
|
int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno)
|
|
{
|
|
struct nilfs_cpinfo ci;
|
|
ssize_t nci;
|
|
int ret;
|
|
|
|
/* checkpoint number 0 is invalid */
|
|
if (cno == 0)
|
|
return -ENOENT;
|
|
nci = nilfs_cpfile_do_get_cpinfo(cpfile, cno, &ci, 1);
|
|
if (nci < 0)
|
|
return nci;
|
|
else if (nci == 0 || ci.ci_cno != cno)
|
|
return -ENOENT;
|
|
|
|
/* cannot delete the latest checkpoint nor snapshots */
|
|
ret = nilfs_cpinfo_snapshot(&ci);
|
|
if (ret < 0)
|
|
return ret;
|
|
else if (ret > 0 || cno == nilfs_mdt_cno(cpfile) - 1)
|
|
return -EPERM;
|
|
|
|
return nilfs_cpfile_delete_checkpoints(cpfile, cno, cno + 1);
|
|
}
|
|
|
|
static struct nilfs_snapshot_list *
|
|
nilfs_cpfile_block_get_snapshot_list(const struct inode *cpfile,
|
|
__u64 cno,
|
|
struct buffer_head *bh,
|
|
void *kaddr)
|
|
{
|
|
struct nilfs_cpfile_header *header;
|
|
struct nilfs_checkpoint *cp;
|
|
struct nilfs_snapshot_list *list;
|
|
|
|
if (cno != 0) {
|
|
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
|
|
list = &cp->cp_snapshot_list;
|
|
} else {
|
|
header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
|
|
list = &header->ch_snapshot_list;
|
|
}
|
|
return list;
|
|
}
|
|
|
|
static int nilfs_cpfile_set_snapshot(struct inode *cpfile, __u64 cno)
|
|
{
|
|
struct buffer_head *header_bh, *curr_bh, *prev_bh, *cp_bh;
|
|
struct nilfs_cpfile_header *header;
|
|
struct nilfs_checkpoint *cp;
|
|
struct nilfs_snapshot_list *list;
|
|
__u64 curr, prev;
|
|
unsigned long curr_blkoff, prev_blkoff;
|
|
void *kaddr;
|
|
int ret;
|
|
|
|
down_write(&NILFS_MDT(cpfile)->mi_sem);
|
|
|
|
ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
|
|
if (ret < 0)
|
|
goto out_sem;
|
|
kaddr = kmap_atomic(cp_bh->b_page, KM_USER0);
|
|
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
|
|
if (nilfs_checkpoint_invalid(cp)) {
|
|
ret = -ENOENT;
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
goto out_cp;
|
|
}
|
|
if (nilfs_checkpoint_snapshot(cp)) {
|
|
ret = 0;
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
goto out_cp;
|
|
}
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
|
|
if (ret < 0)
|
|
goto out_cp;
|
|
kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
|
|
header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
|
|
list = &header->ch_snapshot_list;
|
|
curr_bh = header_bh;
|
|
get_bh(curr_bh);
|
|
curr = 0;
|
|
curr_blkoff = 0;
|
|
prev = le64_to_cpu(list->ssl_prev);
|
|
while (prev > cno) {
|
|
prev_blkoff = nilfs_cpfile_get_blkoff(cpfile, prev);
|
|
curr = prev;
|
|
if (curr_blkoff != prev_blkoff) {
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
brelse(curr_bh);
|
|
ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr,
|
|
0, &curr_bh);
|
|
if (ret < 0)
|
|
goto out_header;
|
|
kaddr = kmap_atomic(curr_bh->b_page, KM_USER0);
|
|
}
|
|
curr_blkoff = prev_blkoff;
|
|
cp = nilfs_cpfile_block_get_checkpoint(
|
|
cpfile, curr, curr_bh, kaddr);
|
|
list = &cp->cp_snapshot_list;
|
|
prev = le64_to_cpu(list->ssl_prev);
|
|
}
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
if (prev != 0) {
|
|
ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
|
|
&prev_bh);
|
|
if (ret < 0)
|
|
goto out_curr;
|
|
} else {
|
|
prev_bh = header_bh;
|
|
get_bh(prev_bh);
|
|
}
|
|
|
|
kaddr = kmap_atomic(curr_bh->b_page, KM_USER0);
|
|
list = nilfs_cpfile_block_get_snapshot_list(
|
|
cpfile, curr, curr_bh, kaddr);
|
|
list->ssl_prev = cpu_to_le64(cno);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
kaddr = kmap_atomic(cp_bh->b_page, KM_USER0);
|
|
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
|
|
cp->cp_snapshot_list.ssl_next = cpu_to_le64(curr);
|
|
cp->cp_snapshot_list.ssl_prev = cpu_to_le64(prev);
|
|
nilfs_checkpoint_set_snapshot(cp);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
kaddr = kmap_atomic(prev_bh->b_page, KM_USER0);
|
|
list = nilfs_cpfile_block_get_snapshot_list(
|
|
cpfile, prev, prev_bh, kaddr);
|
|
list->ssl_next = cpu_to_le64(cno);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
|
|
header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
|
|
le64_add_cpu(&header->ch_nsnapshots, 1);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
nilfs_mdt_mark_buffer_dirty(prev_bh);
|
|
nilfs_mdt_mark_buffer_dirty(curr_bh);
|
|
nilfs_mdt_mark_buffer_dirty(cp_bh);
|
|
nilfs_mdt_mark_buffer_dirty(header_bh);
|
|
nilfs_mdt_mark_dirty(cpfile);
|
|
|
|
brelse(prev_bh);
|
|
|
|
out_curr:
|
|
brelse(curr_bh);
|
|
|
|
out_header:
|
|
brelse(header_bh);
|
|
|
|
out_cp:
|
|
brelse(cp_bh);
|
|
|
|
out_sem:
|
|
up_write(&NILFS_MDT(cpfile)->mi_sem);
|
|
return ret;
|
|
}
|
|
|
|
static int nilfs_cpfile_clear_snapshot(struct inode *cpfile, __u64 cno)
|
|
{
|
|
struct buffer_head *header_bh, *next_bh, *prev_bh, *cp_bh;
|
|
struct nilfs_cpfile_header *header;
|
|
struct nilfs_checkpoint *cp;
|
|
struct nilfs_snapshot_list *list;
|
|
__u64 next, prev;
|
|
void *kaddr;
|
|
int ret;
|
|
|
|
down_write(&NILFS_MDT(cpfile)->mi_sem);
|
|
|
|
ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh);
|
|
if (ret < 0)
|
|
goto out_sem;
|
|
kaddr = kmap_atomic(cp_bh->b_page, KM_USER0);
|
|
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
|
|
if (nilfs_checkpoint_invalid(cp)) {
|
|
ret = -ENOENT;
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
goto out_cp;
|
|
}
|
|
if (!nilfs_checkpoint_snapshot(cp)) {
|
|
ret = 0;
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
goto out_cp;
|
|
}
|
|
|
|
list = &cp->cp_snapshot_list;
|
|
next = le64_to_cpu(list->ssl_next);
|
|
prev = le64_to_cpu(list->ssl_prev);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
ret = nilfs_cpfile_get_header_block(cpfile, &header_bh);
|
|
if (ret < 0)
|
|
goto out_cp;
|
|
if (next != 0) {
|
|
ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, 0,
|
|
&next_bh);
|
|
if (ret < 0)
|
|
goto out_header;
|
|
} else {
|
|
next_bh = header_bh;
|
|
get_bh(next_bh);
|
|
}
|
|
if (prev != 0) {
|
|
ret = nilfs_cpfile_get_checkpoint_block(cpfile, prev, 0,
|
|
&prev_bh);
|
|
if (ret < 0)
|
|
goto out_next;
|
|
} else {
|
|
prev_bh = header_bh;
|
|
get_bh(prev_bh);
|
|
}
|
|
|
|
kaddr = kmap_atomic(next_bh->b_page, KM_USER0);
|
|
list = nilfs_cpfile_block_get_snapshot_list(
|
|
cpfile, next, next_bh, kaddr);
|
|
list->ssl_prev = cpu_to_le64(prev);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
kaddr = kmap_atomic(prev_bh->b_page, KM_USER0);
|
|
list = nilfs_cpfile_block_get_snapshot_list(
|
|
cpfile, prev, prev_bh, kaddr);
|
|
list->ssl_next = cpu_to_le64(next);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
kaddr = kmap_atomic(cp_bh->b_page, KM_USER0);
|
|
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr);
|
|
cp->cp_snapshot_list.ssl_next = cpu_to_le64(0);
|
|
cp->cp_snapshot_list.ssl_prev = cpu_to_le64(0);
|
|
nilfs_checkpoint_clear_snapshot(cp);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
|
|
header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr);
|
|
le64_add_cpu(&header->ch_nsnapshots, -1);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
|
|
nilfs_mdt_mark_buffer_dirty(next_bh);
|
|
nilfs_mdt_mark_buffer_dirty(prev_bh);
|
|
nilfs_mdt_mark_buffer_dirty(cp_bh);
|
|
nilfs_mdt_mark_buffer_dirty(header_bh);
|
|
nilfs_mdt_mark_dirty(cpfile);
|
|
|
|
brelse(prev_bh);
|
|
|
|
out_next:
|
|
brelse(next_bh);
|
|
|
|
out_header:
|
|
brelse(header_bh);
|
|
|
|
out_cp:
|
|
brelse(cp_bh);
|
|
|
|
out_sem:
|
|
up_write(&NILFS_MDT(cpfile)->mi_sem);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* nilfs_cpfile_is_snapshot -
|
|
* @cpfile: inode of checkpoint file
|
|
* @cno: checkpoint number
|
|
*
|
|
* Description:
|
|
*
|
|
* Return Value: On success, 1 is returned if the checkpoint specified by
|
|
* @cno is a snapshot, or 0 if not. On error, one of the following negative
|
|
* error codes is returned.
|
|
*
|
|
* %-EIO - I/O error.
|
|
*
|
|
* %-ENOMEM - Insufficient amount of memory available.
|
|
*
|
|
* %-ENOENT - No such checkpoint.
|
|
*/
|
|
int nilfs_cpfile_is_snapshot(struct inode *cpfile, __u64 cno)
|
|
{
|
|
struct buffer_head *bh;
|
|
struct nilfs_checkpoint *cp;
|
|
void *kaddr;
|
|
int ret;
|
|
|
|
down_read(&NILFS_MDT(cpfile)->mi_sem);
|
|
|
|
ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &bh);
|
|
if (ret < 0)
|
|
goto out;
|
|
kaddr = kmap_atomic(bh->b_page, KM_USER0);
|
|
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);
|
|
ret = nilfs_checkpoint_snapshot(cp);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
brelse(bh);
|
|
|
|
out:
|
|
up_read(&NILFS_MDT(cpfile)->mi_sem);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* nilfs_cpfile_change_cpmode - change checkpoint mode
|
|
* @cpfile: inode of checkpoint file
|
|
* @cno: checkpoint number
|
|
* @status: mode of checkpoint
|
|
*
|
|
* Description: nilfs_change_cpmode() changes the mode of the checkpoint
|
|
* specified by @cno. The mode @mode is NILFS_CHECKPOINT or NILFS_SNAPSHOT.
|
|
*
|
|
* 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.
|
|
*
|
|
* %-ENOENT - No such checkpoint.
|
|
*/
|
|
int nilfs_cpfile_change_cpmode(struct inode *cpfile, __u64 cno, int mode)
|
|
{
|
|
struct the_nilfs *nilfs;
|
|
int ret;
|
|
|
|
nilfs = NILFS_MDT(cpfile)->mi_nilfs;
|
|
|
|
switch (mode) {
|
|
case NILFS_CHECKPOINT:
|
|
/*
|
|
* Check for protecting existing snapshot mounts:
|
|
* bd_mount_sem is used to make this operation atomic and
|
|
* exclusive with a new mount job. Though it doesn't cover
|
|
* umount, it's enough for the purpose.
|
|
*/
|
|
down(&nilfs->ns_bdev->bd_mount_sem);
|
|
if (nilfs_checkpoint_is_mounted(nilfs, cno, 1)) {
|
|
/* Current implementation does not have to protect
|
|
plain read-only mounts since they are exclusive
|
|
with a read/write mount and are protected from the
|
|
cleaner. */
|
|
ret = -EBUSY;
|
|
} else
|
|
ret = nilfs_cpfile_clear_snapshot(cpfile, cno);
|
|
up(&nilfs->ns_bdev->bd_mount_sem);
|
|
return ret;
|
|
case NILFS_SNAPSHOT:
|
|
return nilfs_cpfile_set_snapshot(cpfile, cno);
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* nilfs_cpfile_get_stat - get checkpoint statistics
|
|
* @cpfile: inode of checkpoint file
|
|
* @stat: pointer to a structure of checkpoint statistics
|
|
*
|
|
* Description: nilfs_cpfile_get_stat() returns information about checkpoints.
|
|
*
|
|
* Return Value: On success, 0 is returned, and checkpoints information is
|
|
* stored in the place pointed by @stat. On error, one of the following
|
|
* negative error codes is returned.
|
|
*
|
|
* %-EIO - I/O error.
|
|
*
|
|
* %-ENOMEM - Insufficient amount of memory available.
|
|
*/
|
|
int nilfs_cpfile_get_stat(struct inode *cpfile, struct nilfs_cpstat *cpstat)
|
|
{
|
|
struct buffer_head *bh;
|
|
struct nilfs_cpfile_header *header;
|
|
void *kaddr;
|
|
int ret;
|
|
|
|
down_read(&NILFS_MDT(cpfile)->mi_sem);
|
|
|
|
ret = nilfs_cpfile_get_header_block(cpfile, &bh);
|
|
if (ret < 0)
|
|
goto out_sem;
|
|
kaddr = kmap_atomic(bh->b_page, KM_USER0);
|
|
header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr);
|
|
cpstat->cs_cno = nilfs_mdt_cno(cpfile);
|
|
cpstat->cs_ncps = le64_to_cpu(header->ch_ncheckpoints);
|
|
cpstat->cs_nsss = le64_to_cpu(header->ch_nsnapshots);
|
|
kunmap_atomic(kaddr, KM_USER0);
|
|
brelse(bh);
|
|
|
|
out_sem:
|
|
up_read(&NILFS_MDT(cpfile)->mi_sem);
|
|
return ret;
|
|
}
|