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1015 lines
25 KiB
1015 lines
25 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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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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* Written by Koji Sato. |
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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 "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 = 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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} |
|
|
|
/* 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 __u64 nilfs_cpfile_first_checkpoint_in_block(const struct inode *cpfile, |
|
unsigned long blkoff) |
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{ |
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return (__u64)nilfs_cpfile_checkpoints_per_block(cpfile) * blkoff |
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+ 1 - NILFS_MDT(cpfile)->mi_first_entry_offset; |
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} |
|
|
|
static unsigned long |
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nilfs_cpfile_checkpoints_in_block(const struct inode *cpfile, |
|
__u64 curr, |
|
__u64 max) |
|
{ |
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return min_t(__u64, |
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nilfs_cpfile_checkpoints_per_block(cpfile) - |
|
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, |
|
__u64 cno) |
|
{ |
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return nilfs_cpfile_get_blkoff(cpfile, cno) == 0; |
|
} |
|
|
|
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, |
|
void *kaddr, |
|
unsigned int n) |
|
{ |
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struct nilfs_checkpoint *cp = kaddr + bh_offset(bh); |
|
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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} |
|
|
|
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, |
|
unsigned int n) |
|
{ |
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struct nilfs_checkpoint *cp = kaddr + bh_offset(bh); |
|
unsigned int count; |
|
|
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WARN_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) * |
|
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, |
|
void *kaddr) |
|
{ |
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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); |
|
|
|
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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* nilfs_cpfile_find_checkpoint_block - find and get a buffer on cpfile |
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* @cpfile: inode of cpfile |
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* @start_cno: start checkpoint number (inclusive) |
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* @end_cno: end checkpoint number (inclusive) |
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* @cnop: place to store the next checkpoint number |
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* @bhp: place to store a pointer to buffer_head struct |
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* |
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* Return Value: On success, it returns 0. On error, the following negative |
|
* error code is returned. |
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* |
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* %-ENOMEM - Insufficient memory available. |
|
* |
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* %-EIO - I/O error |
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* |
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* %-ENOENT - no block exists in the range. |
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*/ |
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static int nilfs_cpfile_find_checkpoint_block(struct inode *cpfile, |
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__u64 start_cno, __u64 end_cno, |
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__u64 *cnop, |
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struct buffer_head **bhp) |
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{ |
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unsigned long start, end, blkoff; |
|
int ret; |
|
|
|
if (unlikely(start_cno > end_cno)) |
|
return -ENOENT; |
|
|
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start = nilfs_cpfile_get_blkoff(cpfile, start_cno); |
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end = nilfs_cpfile_get_blkoff(cpfile, end_cno); |
|
|
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ret = nilfs_mdt_find_block(cpfile, start, end, &blkoff, bhp); |
|
if (!ret) |
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*cnop = (blkoff == start) ? start_cno : |
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nilfs_cpfile_first_checkpoint_in_block(cpfile, blkoff); |
|
return ret; |
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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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/** |
|
* 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 |
|
* @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 |
|
* 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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* %-EINVAL - invalid 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; |
|
void *kaddr; |
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int ret; |
|
|
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if (unlikely(cno < 1 || cno > nilfs_mdt_cno(cpfile) || |
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(cno < nilfs_mdt_cno(cpfile) && create))) |
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return -EINVAL; |
|
|
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down_write(&NILFS_MDT(cpfile)->mi_sem); |
|
|
|
ret = nilfs_cpfile_get_header_block(cpfile, &header_bh); |
|
if (ret < 0) |
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goto out_sem; |
|
ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, create, &cp_bh); |
|
if (ret < 0) |
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goto out_header; |
|
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)) { |
|
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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mark_buffer_dirty(cp_bh); |
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|
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kaddr = kmap_atomic(header_bh->b_page); |
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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); |
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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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|
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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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/** |
|
* 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 number |
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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 |
|
* 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 |
|
* negative error codes is returned. |
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* |
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* %-EIO - I/O error. |
|
* |
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* %-ENOMEM - Insufficient amount of memory available. |
|
* |
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* %-EINVAL - invalid checkpoints. |
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*/ |
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int nilfs_cpfile_delete_checkpoints(struct inode *cpfile, |
|
__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, nss, count, i; |
|
|
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if (unlikely(start == 0 || start > end)) { |
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nilfs_err(cpfile->i_sb, |
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"cannot delete checkpoints: invalid range [%llu, %llu)", |
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(unsigned long long)start, (unsigned long long)end); |
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return -EINVAL; |
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} |
|
|
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down_write(&NILFS_MDT(cpfile)->mi_sem); |
|
|
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ret = nilfs_cpfile_get_header_block(cpfile, &header_bh); |
|
if (ret < 0) |
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goto out_sem; |
|
tnicps = 0; |
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nss = 0; |
|
|
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for (cno = start; cno < end; cno += ncps) { |
|
ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, end); |
|
ret = nilfs_cpfile_get_checkpoint_block(cpfile, cno, 0, &cp_bh); |
|
if (ret < 0) { |
|
if (ret != -ENOENT) |
|
break; |
|
/* skip hole */ |
|
ret = 0; |
|
continue; |
|
} |
|
|
|
kaddr = kmap_atomic(cp_bh->b_page); |
|
cp = nilfs_cpfile_block_get_checkpoint( |
|
cpfile, cno, cp_bh, kaddr); |
|
nicps = 0; |
|
for (i = 0; i < ncps; i++, cp = (void *)cp + cpsz) { |
|
if (nilfs_checkpoint_snapshot(cp)) { |
|
nss++; |
|
} else if (!nilfs_checkpoint_invalid(cp)) { |
|
nilfs_checkpoint_set_invalid(cp); |
|
nicps++; |
|
} |
|
} |
|
if (nicps > 0) { |
|
tnicps += nicps; |
|
mark_buffer_dirty(cp_bh); |
|
nilfs_mdt_mark_dirty(cpfile); |
|
if (!nilfs_cpfile_is_in_first(cpfile, cno)) { |
|
count = |
|
nilfs_cpfile_block_sub_valid_checkpoints( |
|
cpfile, cp_bh, kaddr, nicps); |
|
if (count == 0) { |
|
/* make hole */ |
|
kunmap_atomic(kaddr); |
|
brelse(cp_bh); |
|
ret = |
|
nilfs_cpfile_delete_checkpoint_block( |
|
cpfile, cno); |
|
if (ret == 0) |
|
continue; |
|
nilfs_err(cpfile->i_sb, |
|
"error %d deleting checkpoint block", |
|
ret); |
|
break; |
|
} |
|
} |
|
} |
|
|
|
kunmap_atomic(kaddr); |
|
brelse(cp_bh); |
|
} |
|
|
|
if (tnicps > 0) { |
|
kaddr = kmap_atomic(header_bh->b_page); |
|
header = nilfs_cpfile_block_get_header(cpfile, header_bh, |
|
kaddr); |
|
le64_add_cpu(&header->ch_ncheckpoints, -(u64)tnicps); |
|
mark_buffer_dirty(header_bh); |
|
nilfs_mdt_mark_dirty(cpfile); |
|
kunmap_atomic(kaddr); |
|
} |
|
|
|
brelse(header_bh); |
|
if (nss > 0) |
|
ret = -EBUSY; |
|
|
|
out_sem: |
|
up_write(&NILFS_MDT(cpfile)->mi_sem); |
|
return ret; |
|
} |
|
|
|
static void nilfs_cpfile_checkpoint_to_cpinfo(struct inode *cpfile, |
|
struct nilfs_checkpoint *cp, |
|
struct nilfs_cpinfo *ci) |
|
{ |
|
ci->ci_flags = le32_to_cpu(cp->cp_flags); |
|
ci->ci_cno = le64_to_cpu(cp->cp_cno); |
|
ci->ci_create = le64_to_cpu(cp->cp_create); |
|
ci->ci_nblk_inc = le64_to_cpu(cp->cp_nblk_inc); |
|
ci->ci_inodes_count = le64_to_cpu(cp->cp_inodes_count); |
|
ci->ci_blocks_count = le64_to_cpu(cp->cp_blocks_count); |
|
ci->ci_next = le64_to_cpu(cp->cp_snapshot_list.ssl_next); |
|
} |
|
|
|
static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop, |
|
void *buf, unsigned int cisz, |
|
size_t nci) |
|
{ |
|
struct nilfs_checkpoint *cp; |
|
struct nilfs_cpinfo *ci = buf; |
|
struct buffer_head *bh; |
|
size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size; |
|
__u64 cur_cno = nilfs_mdt_cno(cpfile), cno = *cnop; |
|
void *kaddr; |
|
int n, ret; |
|
int ncps, i; |
|
|
|
if (cno == 0) |
|
return -ENOENT; /* checkpoint number 0 is invalid */ |
|
down_read(&NILFS_MDT(cpfile)->mi_sem); |
|
|
|
for (n = 0; n < nci; cno += ncps) { |
|
ret = nilfs_cpfile_find_checkpoint_block( |
|
cpfile, cno, cur_cno - 1, &cno, &bh); |
|
if (ret < 0) { |
|
if (likely(ret == -ENOENT)) |
|
break; |
|
goto out; |
|
} |
|
ncps = nilfs_cpfile_checkpoints_in_block(cpfile, cno, cur_cno); |
|
|
|
kaddr = kmap_atomic(bh->b_page); |
|
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); |
|
for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) { |
|
if (!nilfs_checkpoint_invalid(cp)) { |
|
nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, |
|
ci); |
|
ci = (void *)ci + cisz; |
|
n++; |
|
} |
|
} |
|
kunmap_atomic(kaddr); |
|
brelse(bh); |
|
} |
|
|
|
ret = n; |
|
if (n > 0) { |
|
ci = (void *)ci - cisz; |
|
*cnop = ci->ci_cno + 1; |
|
} |
|
|
|
out: |
|
up_read(&NILFS_MDT(cpfile)->mi_sem); |
|
return ret; |
|
} |
|
|
|
static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop, |
|
void *buf, unsigned int cisz, |
|
size_t nci) |
|
{ |
|
struct buffer_head *bh; |
|
struct nilfs_cpfile_header *header; |
|
struct nilfs_checkpoint *cp; |
|
struct nilfs_cpinfo *ci = buf; |
|
__u64 curr = *cnop, next; |
|
unsigned long curr_blkoff, next_blkoff; |
|
void *kaddr; |
|
int n = 0, ret; |
|
|
|
down_read(&NILFS_MDT(cpfile)->mi_sem); |
|
|
|
if (curr == 0) { |
|
ret = nilfs_cpfile_get_header_block(cpfile, &bh); |
|
if (ret < 0) |
|
goto out; |
|
kaddr = kmap_atomic(bh->b_page); |
|
header = nilfs_cpfile_block_get_header(cpfile, bh, kaddr); |
|
curr = le64_to_cpu(header->ch_snapshot_list.ssl_next); |
|
kunmap_atomic(kaddr); |
|
brelse(bh); |
|
if (curr == 0) { |
|
ret = 0; |
|
goto out; |
|
} |
|
} else if (unlikely(curr == ~(__u64)0)) { |
|
ret = 0; |
|
goto out; |
|
} |
|
|
|
curr_blkoff = nilfs_cpfile_get_blkoff(cpfile, curr); |
|
ret = nilfs_cpfile_get_checkpoint_block(cpfile, curr, 0, &bh); |
|
if (unlikely(ret < 0)) { |
|
if (ret == -ENOENT) |
|
ret = 0; /* No snapshots (started from a hole block) */ |
|
goto out; |
|
} |
|
kaddr = kmap_atomic(bh->b_page); |
|
while (n < nci) { |
|
cp = nilfs_cpfile_block_get_checkpoint(cpfile, curr, bh, kaddr); |
|
curr = ~(__u64)0; /* Terminator */ |
|
if (unlikely(nilfs_checkpoint_invalid(cp) || |
|
!nilfs_checkpoint_snapshot(cp))) |
|
break; |
|
nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, ci); |
|
ci = (void *)ci + cisz; |
|
n++; |
|
next = le64_to_cpu(cp->cp_snapshot_list.ssl_next); |
|
if (next == 0) |
|
break; /* reach end of the snapshot list */ |
|
|
|
next_blkoff = nilfs_cpfile_get_blkoff(cpfile, next); |
|
if (curr_blkoff != next_blkoff) { |
|
kunmap_atomic(kaddr); |
|
brelse(bh); |
|
ret = nilfs_cpfile_get_checkpoint_block(cpfile, next, |
|
0, &bh); |
|
if (unlikely(ret < 0)) { |
|
WARN_ON(ret == -ENOENT); |
|
goto out; |
|
} |
|
kaddr = kmap_atomic(bh->b_page); |
|
} |
|
curr = next; |
|
curr_blkoff = next_blkoff; |
|
} |
|
kunmap_atomic(kaddr); |
|
brelse(bh); |
|
*cnop = curr; |
|
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 *cnop, int mode, |
|
void *buf, unsigned int cisz, size_t nci) |
|
{ |
|
switch (mode) { |
|
case NILFS_CHECKPOINT: |
|
return nilfs_cpfile_do_get_cpinfo(cpfile, cnop, buf, cisz, nci); |
|
case NILFS_SNAPSHOT: |
|
return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, buf, cisz, nci); |
|
default: |
|
return -EINVAL; |
|
} |
|
} |
|
|
|
/** |
|
* nilfs_cpfile_delete_checkpoint - |
|
* @cpfile: |
|
* @cno: |
|
*/ |
|
int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno) |
|
{ |
|
struct nilfs_cpinfo ci; |
|
__u64 tcno = cno; |
|
ssize_t nci; |
|
|
|
nci = nilfs_cpfile_do_get_cpinfo(cpfile, &tcno, &ci, sizeof(ci), 1); |
|
if (nci < 0) |
|
return nci; |
|
else if (nci == 0 || ci.ci_cno != cno) |
|
return -ENOENT; |
|
else if (nilfs_cpinfo_snapshot(&ci)) |
|
return -EBUSY; |
|
|
|
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; |
|
|
|
if (cno == 0) |
|
return -ENOENT; /* checkpoint number 0 is invalid */ |
|
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); |
|
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); |
|
if (nilfs_checkpoint_invalid(cp)) { |
|
ret = -ENOENT; |
|
kunmap_atomic(kaddr); |
|
goto out_cp; |
|
} |
|
if (nilfs_checkpoint_snapshot(cp)) { |
|
ret = 0; |
|
kunmap_atomic(kaddr); |
|
goto out_cp; |
|
} |
|
kunmap_atomic(kaddr); |
|
|
|
ret = nilfs_cpfile_get_header_block(cpfile, &header_bh); |
|
if (ret < 0) |
|
goto out_cp; |
|
kaddr = kmap_atomic(header_bh->b_page); |
|
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); |
|
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); |
|
} |
|
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); |
|
|
|
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); |
|
list = nilfs_cpfile_block_get_snapshot_list( |
|
cpfile, curr, curr_bh, kaddr); |
|
list->ssl_prev = cpu_to_le64(cno); |
|
kunmap_atomic(kaddr); |
|
|
|
kaddr = kmap_atomic(cp_bh->b_page); |
|
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); |
|
|
|
kaddr = kmap_atomic(prev_bh->b_page); |
|
list = nilfs_cpfile_block_get_snapshot_list( |
|
cpfile, prev, prev_bh, kaddr); |
|
list->ssl_next = cpu_to_le64(cno); |
|
kunmap_atomic(kaddr); |
|
|
|
kaddr = kmap_atomic(header_bh->b_page); |
|
header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr); |
|
le64_add_cpu(&header->ch_nsnapshots, 1); |
|
kunmap_atomic(kaddr); |
|
|
|
mark_buffer_dirty(prev_bh); |
|
mark_buffer_dirty(curr_bh); |
|
mark_buffer_dirty(cp_bh); |
|
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; |
|
|
|
if (cno == 0) |
|
return -ENOENT; /* checkpoint number 0 is invalid */ |
|
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); |
|
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, cp_bh, kaddr); |
|
if (nilfs_checkpoint_invalid(cp)) { |
|
ret = -ENOENT; |
|
kunmap_atomic(kaddr); |
|
goto out_cp; |
|
} |
|
if (!nilfs_checkpoint_snapshot(cp)) { |
|
ret = 0; |
|
kunmap_atomic(kaddr); |
|
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); |
|
|
|
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); |
|
list = nilfs_cpfile_block_get_snapshot_list( |
|
cpfile, next, next_bh, kaddr); |
|
list->ssl_prev = cpu_to_le64(prev); |
|
kunmap_atomic(kaddr); |
|
|
|
kaddr = kmap_atomic(prev_bh->b_page); |
|
list = nilfs_cpfile_block_get_snapshot_list( |
|
cpfile, prev, prev_bh, kaddr); |
|
list->ssl_next = cpu_to_le64(next); |
|
kunmap_atomic(kaddr); |
|
|
|
kaddr = kmap_atomic(cp_bh->b_page); |
|
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); |
|
|
|
kaddr = kmap_atomic(header_bh->b_page); |
|
header = nilfs_cpfile_block_get_header(cpfile, header_bh, kaddr); |
|
le64_add_cpu(&header->ch_nsnapshots, -1); |
|
kunmap_atomic(kaddr); |
|
|
|
mark_buffer_dirty(next_bh); |
|
mark_buffer_dirty(prev_bh); |
|
mark_buffer_dirty(cp_bh); |
|
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; |
|
|
|
/* |
|
* CP number is invalid if it's zero or larger than the |
|
* largest existing one. |
|
*/ |
|
if (cno == 0 || cno >= nilfs_mdt_cno(cpfile)) |
|
return -ENOENT; |
|
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); |
|
cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr); |
|
if (nilfs_checkpoint_invalid(cp)) |
|
ret = -ENOENT; |
|
else |
|
ret = nilfs_checkpoint_snapshot(cp); |
|
kunmap_atomic(kaddr); |
|
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 |
|
* @mode: 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) |
|
{ |
|
int ret; |
|
|
|
switch (mode) { |
|
case NILFS_CHECKPOINT: |
|
if (nilfs_checkpoint_is_mounted(cpfile->i_sb, cno)) |
|
/* |
|
* 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); |
|
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 |
|
* @cpstat: 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 @cpstat. 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); |
|
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); |
|
brelse(bh); |
|
|
|
out_sem: |
|
up_read(&NILFS_MDT(cpfile)->mi_sem); |
|
return ret; |
|
} |
|
|
|
/** |
|
* nilfs_cpfile_read - read or get cpfile inode |
|
* @sb: super block instance |
|
* @cpsize: size of a checkpoint entry |
|
* @raw_inode: on-disk cpfile inode |
|
* @inodep: buffer to store the inode |
|
*/ |
|
int nilfs_cpfile_read(struct super_block *sb, size_t cpsize, |
|
struct nilfs_inode *raw_inode, struct inode **inodep) |
|
{ |
|
struct inode *cpfile; |
|
int err; |
|
|
|
if (cpsize > sb->s_blocksize) { |
|
nilfs_err(sb, "too large checkpoint size: %zu bytes", cpsize); |
|
return -EINVAL; |
|
} else if (cpsize < NILFS_MIN_CHECKPOINT_SIZE) { |
|
nilfs_err(sb, "too small checkpoint size: %zu bytes", cpsize); |
|
return -EINVAL; |
|
} |
|
|
|
cpfile = nilfs_iget_locked(sb, NULL, NILFS_CPFILE_INO); |
|
if (unlikely(!cpfile)) |
|
return -ENOMEM; |
|
if (!(cpfile->i_state & I_NEW)) |
|
goto out; |
|
|
|
err = nilfs_mdt_init(cpfile, NILFS_MDT_GFP, 0); |
|
if (err) |
|
goto failed; |
|
|
|
nilfs_mdt_set_entry_size(cpfile, cpsize, |
|
sizeof(struct nilfs_cpfile_header)); |
|
|
|
err = nilfs_read_inode_common(cpfile, raw_inode); |
|
if (err) |
|
goto failed; |
|
|
|
unlock_new_inode(cpfile); |
|
out: |
|
*inodep = cpfile; |
|
return 0; |
|
failed: |
|
iget_failed(cpfile); |
|
return err; |
|
}
|
|
|