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384 lines
11 KiB
384 lines
11 KiB
/* SPDX-License-Identifier: GPL-2.0+ */ |
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/* |
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* the_nilfs shared structure. |
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* |
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* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. |
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* |
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* Written by Ryusuke Konishi. |
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* |
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*/ |
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#ifndef _THE_NILFS_H |
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#define _THE_NILFS_H |
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#include <linux/types.h> |
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#include <linux/buffer_head.h> |
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#include <linux/rbtree.h> |
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#include <linux/fs.h> |
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#include <linux/blkdev.h> |
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#include <linux/backing-dev.h> |
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#include <linux/slab.h> |
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#include <linux/refcount.h> |
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struct nilfs_sc_info; |
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struct nilfs_sysfs_dev_subgroups; |
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/* the_nilfs struct */ |
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enum { |
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THE_NILFS_INIT = 0, /* Information from super_block is set */ |
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THE_NILFS_DISCONTINUED, /* 'next' pointer chain has broken */ |
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THE_NILFS_GC_RUNNING, /* gc process is running */ |
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THE_NILFS_SB_DIRTY, /* super block is dirty */ |
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}; |
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/** |
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* struct the_nilfs - struct to supervise multiple nilfs mount points |
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* @ns_flags: flags |
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* @ns_flushed_device: flag indicating if all volatile data was flushed |
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* @ns_sb: back pointer to super block instance |
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* @ns_bdev: block device |
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* @ns_sem: semaphore for shared states |
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* @ns_snapshot_mount_mutex: mutex to protect snapshot mounts |
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* @ns_sbh: buffer heads of on-disk super blocks |
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* @ns_sbp: pointers to super block data |
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* @ns_sbwtime: previous write time of super block |
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* @ns_sbwcount: write count of super block |
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* @ns_sbsize: size of valid data in super block |
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* @ns_mount_state: file system state |
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* @ns_sb_update_freq: interval of periodical update of superblocks (in seconds) |
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* @ns_seg_seq: segment sequence counter |
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* @ns_segnum: index number of the latest full segment. |
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* @ns_nextnum: index number of the full segment index to be used next |
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* @ns_pseg_offset: offset of next partial segment in the current full segment |
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* @ns_cno: next checkpoint number |
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* @ns_ctime: write time of the last segment |
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* @ns_nongc_ctime: write time of the last segment not for cleaner operation |
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* @ns_ndirtyblks: Number of dirty data blocks |
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* @ns_last_segment_lock: lock protecting fields for the latest segment |
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* @ns_last_pseg: start block number of the latest segment |
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* @ns_last_seq: sequence value of the latest segment |
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* @ns_last_cno: checkpoint number of the latest segment |
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* @ns_prot_seq: least sequence number of segments which must not be reclaimed |
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* @ns_prev_seq: base sequence number used to decide if advance log cursor |
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* @ns_writer: log writer |
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* @ns_segctor_sem: semaphore protecting log write |
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* @ns_dat: DAT file inode |
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* @ns_cpfile: checkpoint file inode |
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* @ns_sufile: segusage file inode |
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* @ns_cptree: rb-tree of all mounted checkpoints (nilfs_root) |
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* @ns_cptree_lock: lock protecting @ns_cptree |
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* @ns_dirty_files: list of dirty files |
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* @ns_inode_lock: lock protecting @ns_dirty_files |
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* @ns_gc_inodes: dummy inodes to keep live blocks |
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* @ns_next_generation: next generation number for inodes |
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* @ns_next_gen_lock: lock protecting @ns_next_generation |
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* @ns_mount_opt: mount options |
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* @ns_resuid: uid for reserved blocks |
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* @ns_resgid: gid for reserved blocks |
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* @ns_interval: checkpoint creation interval |
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* @ns_watermark: watermark for the number of dirty buffers |
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* @ns_blocksize_bits: bit length of block size |
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* @ns_blocksize: block size |
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* @ns_nsegments: number of segments in filesystem |
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* @ns_blocks_per_segment: number of blocks per segment |
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* @ns_r_segments_percentage: reserved segments percentage |
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* @ns_nrsvsegs: number of reserved segments |
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* @ns_first_data_block: block number of first data block |
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* @ns_inode_size: size of on-disk inode |
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* @ns_first_ino: first not-special inode number |
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* @ns_crc_seed: seed value of CRC32 calculation |
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* @ns_dev_kobj: /sys/fs/<nilfs>/<device> |
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* @ns_dev_kobj_unregister: completion state |
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* @ns_dev_subgroups: <device> subgroups pointer |
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*/ |
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struct the_nilfs { |
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unsigned long ns_flags; |
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int ns_flushed_device; |
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struct super_block *ns_sb; |
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struct block_device *ns_bdev; |
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struct rw_semaphore ns_sem; |
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struct mutex ns_snapshot_mount_mutex; |
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/* |
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* used for |
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* - loading the latest checkpoint exclusively. |
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* - allocating a new full segment. |
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*/ |
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struct buffer_head *ns_sbh[2]; |
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struct nilfs_super_block *ns_sbp[2]; |
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time64_t ns_sbwtime; |
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unsigned int ns_sbwcount; |
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unsigned int ns_sbsize; |
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unsigned int ns_mount_state; |
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unsigned int ns_sb_update_freq; |
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/* |
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* The following fields are updated by a writable FS-instance. |
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* These fields are protected by ns_segctor_sem outside load_nilfs(). |
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*/ |
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u64 ns_seg_seq; |
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__u64 ns_segnum; |
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__u64 ns_nextnum; |
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unsigned long ns_pseg_offset; |
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__u64 ns_cno; |
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time64_t ns_ctime; |
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time64_t ns_nongc_ctime; |
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atomic_t ns_ndirtyblks; |
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/* |
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* The following fields hold information on the latest partial segment |
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* written to disk with a super root. These fields are protected by |
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* ns_last_segment_lock. |
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*/ |
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spinlock_t ns_last_segment_lock; |
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sector_t ns_last_pseg; |
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u64 ns_last_seq; |
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__u64 ns_last_cno; |
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u64 ns_prot_seq; |
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u64 ns_prev_seq; |
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struct nilfs_sc_info *ns_writer; |
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struct rw_semaphore ns_segctor_sem; |
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/* |
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* Following fields are lock free except for the period before |
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* the_nilfs is initialized. |
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*/ |
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struct inode *ns_dat; |
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struct inode *ns_cpfile; |
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struct inode *ns_sufile; |
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/* Checkpoint tree */ |
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struct rb_root ns_cptree; |
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spinlock_t ns_cptree_lock; |
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/* Dirty inode list */ |
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struct list_head ns_dirty_files; |
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spinlock_t ns_inode_lock; |
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/* GC inode list */ |
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struct list_head ns_gc_inodes; |
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/* Inode allocator */ |
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u32 ns_next_generation; |
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spinlock_t ns_next_gen_lock; |
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/* Mount options */ |
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unsigned long ns_mount_opt; |
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uid_t ns_resuid; |
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gid_t ns_resgid; |
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unsigned long ns_interval; |
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unsigned long ns_watermark; |
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/* Disk layout information (static) */ |
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unsigned int ns_blocksize_bits; |
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unsigned int ns_blocksize; |
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unsigned long ns_nsegments; |
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unsigned long ns_blocks_per_segment; |
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unsigned long ns_r_segments_percentage; |
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unsigned long ns_nrsvsegs; |
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unsigned long ns_first_data_block; |
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int ns_inode_size; |
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int ns_first_ino; |
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u32 ns_crc_seed; |
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/* /sys/fs/<nilfs>/<device> */ |
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struct kobject ns_dev_kobj; |
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struct completion ns_dev_kobj_unregister; |
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struct nilfs_sysfs_dev_subgroups *ns_dev_subgroups; |
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}; |
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#define THE_NILFS_FNS(bit, name) \ |
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static inline void set_nilfs_##name(struct the_nilfs *nilfs) \ |
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{ \ |
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set_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ |
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} \ |
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static inline void clear_nilfs_##name(struct the_nilfs *nilfs) \ |
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{ \ |
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clear_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ |
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} \ |
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static inline int nilfs_##name(struct the_nilfs *nilfs) \ |
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{ \ |
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return test_bit(THE_NILFS_##bit, &(nilfs)->ns_flags); \ |
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} |
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THE_NILFS_FNS(INIT, init) |
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THE_NILFS_FNS(DISCONTINUED, discontinued) |
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THE_NILFS_FNS(GC_RUNNING, gc_running) |
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THE_NILFS_FNS(SB_DIRTY, sb_dirty) |
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/* |
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* Mount option operations |
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*/ |
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#define nilfs_clear_opt(nilfs, opt) \ |
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((nilfs)->ns_mount_opt &= ~NILFS_MOUNT_##opt) |
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#define nilfs_set_opt(nilfs, opt) \ |
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((nilfs)->ns_mount_opt |= NILFS_MOUNT_##opt) |
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#define nilfs_test_opt(nilfs, opt) ((nilfs)->ns_mount_opt & NILFS_MOUNT_##opt) |
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#define nilfs_write_opt(nilfs, mask, opt) \ |
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((nilfs)->ns_mount_opt = \ |
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(((nilfs)->ns_mount_opt & ~NILFS_MOUNT_##mask) | \ |
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NILFS_MOUNT_##opt)) \ |
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/** |
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* struct nilfs_root - nilfs root object |
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* @cno: checkpoint number |
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* @rb_node: red-black tree node |
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* @count: refcount of this structure |
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* @nilfs: nilfs object |
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* @ifile: inode file |
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* @inodes_count: number of inodes |
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* @blocks_count: number of blocks |
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* @snapshot_kobj: /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> |
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* @snapshot_kobj_unregister: completion state for kernel object |
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*/ |
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struct nilfs_root { |
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__u64 cno; |
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struct rb_node rb_node; |
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refcount_t count; |
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struct the_nilfs *nilfs; |
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struct inode *ifile; |
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atomic64_t inodes_count; |
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atomic64_t blocks_count; |
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/* /sys/fs/<nilfs>/<device>/mounted_snapshots/<snapshot> */ |
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struct kobject snapshot_kobj; |
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struct completion snapshot_kobj_unregister; |
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}; |
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/* Special checkpoint number */ |
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#define NILFS_CPTREE_CURRENT_CNO 0 |
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/* Minimum interval of periodical update of superblocks (in seconds) */ |
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#define NILFS_SB_FREQ 10 |
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static inline int nilfs_sb_need_update(struct the_nilfs *nilfs) |
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{ |
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u64 t = ktime_get_real_seconds(); |
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return t < nilfs->ns_sbwtime || |
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t > nilfs->ns_sbwtime + nilfs->ns_sb_update_freq; |
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} |
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static inline int nilfs_sb_will_flip(struct the_nilfs *nilfs) |
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{ |
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int flip_bits = nilfs->ns_sbwcount & 0x0FL; |
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return (flip_bits != 0x08 && flip_bits != 0x0F); |
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} |
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void nilfs_set_last_segment(struct the_nilfs *, sector_t, u64, __u64); |
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struct the_nilfs *alloc_nilfs(struct super_block *sb); |
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void destroy_nilfs(struct the_nilfs *nilfs); |
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int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data); |
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int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb); |
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unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs); |
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void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs); |
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int nilfs_discard_segments(struct the_nilfs *, __u64 *, size_t); |
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int nilfs_count_free_blocks(struct the_nilfs *, sector_t *); |
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struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno); |
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struct nilfs_root *nilfs_find_or_create_root(struct the_nilfs *nilfs, |
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__u64 cno); |
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void nilfs_put_root(struct nilfs_root *root); |
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int nilfs_near_disk_full(struct the_nilfs *); |
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void nilfs_fall_back_super_block(struct the_nilfs *); |
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void nilfs_swap_super_block(struct the_nilfs *); |
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static inline void nilfs_get_root(struct nilfs_root *root) |
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{ |
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refcount_inc(&root->count); |
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} |
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static inline int nilfs_valid_fs(struct the_nilfs *nilfs) |
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{ |
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unsigned int valid_fs; |
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down_read(&nilfs->ns_sem); |
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valid_fs = (nilfs->ns_mount_state & NILFS_VALID_FS); |
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up_read(&nilfs->ns_sem); |
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return valid_fs; |
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} |
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static inline void |
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nilfs_get_segment_range(struct the_nilfs *nilfs, __u64 segnum, |
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sector_t *seg_start, sector_t *seg_end) |
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{ |
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*seg_start = (sector_t)nilfs->ns_blocks_per_segment * segnum; |
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*seg_end = *seg_start + nilfs->ns_blocks_per_segment - 1; |
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if (segnum == 0) |
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*seg_start = nilfs->ns_first_data_block; |
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} |
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static inline sector_t |
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nilfs_get_segment_start_blocknr(struct the_nilfs *nilfs, __u64 segnum) |
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{ |
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return (segnum == 0) ? nilfs->ns_first_data_block : |
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(sector_t)nilfs->ns_blocks_per_segment * segnum; |
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} |
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static inline __u64 |
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nilfs_get_segnum_of_block(struct the_nilfs *nilfs, sector_t blocknr) |
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{ |
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sector_t segnum = blocknr; |
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sector_div(segnum, nilfs->ns_blocks_per_segment); |
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return segnum; |
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} |
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static inline void |
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nilfs_terminate_segment(struct the_nilfs *nilfs, sector_t seg_start, |
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sector_t seg_end) |
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{ |
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/* terminate the current full segment (used in case of I/O-error) */ |
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nilfs->ns_pseg_offset = seg_end - seg_start + 1; |
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} |
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static inline void nilfs_shift_to_next_segment(struct the_nilfs *nilfs) |
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{ |
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/* move forward with a full segment */ |
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nilfs->ns_segnum = nilfs->ns_nextnum; |
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nilfs->ns_pseg_offset = 0; |
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nilfs->ns_seg_seq++; |
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} |
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static inline __u64 nilfs_last_cno(struct the_nilfs *nilfs) |
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{ |
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__u64 cno; |
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spin_lock(&nilfs->ns_last_segment_lock); |
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cno = nilfs->ns_last_cno; |
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spin_unlock(&nilfs->ns_last_segment_lock); |
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return cno; |
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} |
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static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n) |
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{ |
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return n == nilfs->ns_segnum || n == nilfs->ns_nextnum; |
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} |
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static inline int nilfs_flush_device(struct the_nilfs *nilfs) |
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{ |
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int err; |
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if (!nilfs_test_opt(nilfs, BARRIER) || nilfs->ns_flushed_device) |
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return 0; |
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nilfs->ns_flushed_device = 1; |
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/* |
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* the store to ns_flushed_device must not be reordered after |
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* blkdev_issue_flush(). |
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*/ |
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smp_wmb(); |
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err = blkdev_issue_flush(nilfs->ns_bdev); |
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if (err != -EIO) |
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err = 0; |
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return err; |
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} |
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#endif /* _THE_NILFS_H */
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