/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright 2019 Google LLC
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*/
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#ifndef _INCFS_DATA_MGMT_H
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#define _INCFS_DATA_MGMT_H
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#include <linux/cred.h>
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#include <linux/fs.h>
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#include <linux/types.h>
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#include <linux/mutex.h>
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#include <linux/spinlock.h>
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#include <linux/rcupdate.h>
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#include <linux/completion.h>
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#include <linux/wait.h>
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#include <linux/zstd.h>
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#include <crypto/hash.h>
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#include <linux/rwsem.h>
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#include <uapi/linux/incrementalfs.h>
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#include "internal.h"
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#include "pseudo_files.h"
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#define SEGMENTS_PER_FILE 3
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enum LOG_RECORD_TYPE {
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FULL,
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SAME_FILE,
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SAME_FILE_CLOSE_BLOCK,
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SAME_FILE_CLOSE_BLOCK_SHORT,
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SAME_FILE_NEXT_BLOCK,
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SAME_FILE_NEXT_BLOCK_SHORT,
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};
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struct full_record {
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enum LOG_RECORD_TYPE type : 3; /* FULL */
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u32 block_index : 29;
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incfs_uuid_t file_id;
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u64 absolute_ts_us;
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uid_t uid;
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} __packed; /* 32 bytes */
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struct same_file {
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enum LOG_RECORD_TYPE type : 3; /* SAME_FILE */
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u32 block_index : 29;
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uid_t uid;
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u16 relative_ts_us; /* max 2^16 us ~= 64 ms */
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} __packed; /* 10 bytes */
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struct same_file_close_block {
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enum LOG_RECORD_TYPE type : 3; /* SAME_FILE_CLOSE_BLOCK */
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u16 relative_ts_us : 13; /* max 2^13 us ~= 8 ms */
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s16 block_index_delta;
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} __packed; /* 4 bytes */
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struct same_file_close_block_short {
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enum LOG_RECORD_TYPE type : 3; /* SAME_FILE_CLOSE_BLOCK_SHORT */
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u8 relative_ts_tens_us : 5; /* max 2^5*10 us ~= 320 us */
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s8 block_index_delta;
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} __packed; /* 2 bytes */
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struct same_file_next_block {
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enum LOG_RECORD_TYPE type : 3; /* SAME_FILE_NEXT_BLOCK */
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u16 relative_ts_us : 13; /* max 2^13 us ~= 8 ms */
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} __packed; /* 2 bytes */
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struct same_file_next_block_short {
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enum LOG_RECORD_TYPE type : 3; /* SAME_FILE_NEXT_BLOCK_SHORT */
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u8 relative_ts_tens_us : 5; /* max 2^5*10 us ~= 320 us */
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} __packed; /* 1 byte */
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union log_record {
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struct full_record full_record;
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struct same_file same_file;
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struct same_file_close_block same_file_close_block;
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struct same_file_close_block_short same_file_close_block_short;
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struct same_file_next_block same_file_next_block;
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struct same_file_next_block_short same_file_next_block_short;
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};
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struct read_log_state {
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/* Log buffer generation id, incremented on configuration changes */
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u32 generation_id;
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/* Offset in rl_ring_buf to write into. */
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u32 next_offset;
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/* Current number of writer passes over rl_ring_buf */
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u32 current_pass_no;
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/* Current full_record to diff against */
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struct full_record base_record;
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/* Current record number counting from configuration change */
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u64 current_record_no;
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};
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/* A ring buffer to save records about data blocks which were recently read. */
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struct read_log {
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void *rl_ring_buf;
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int rl_size;
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struct read_log_state rl_head;
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struct read_log_state rl_tail;
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/* A lock to protect the above fields */
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spinlock_t rl_lock;
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/* A queue of waiters who want to be notified about reads */
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wait_queue_head_t ml_notif_wq;
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/* A work item to wake up those waiters without slowing down readers */
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struct delayed_work ml_wakeup_work;
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};
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struct mount_options {
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unsigned int read_timeout_ms;
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unsigned int readahead_pages;
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unsigned int read_log_pages;
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unsigned int read_log_wakeup_count;
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bool report_uid;
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char *sysfs_name;
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};
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struct mount_info {
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struct super_block *mi_sb;
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struct path mi_backing_dir_path;
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struct dentry *mi_index_dir;
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/* For stacking mounts, if true, this indicates if the index dir needs
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* to be freed for this SB otherwise it was created by lower level SB */
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bool mi_index_free;
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struct dentry *mi_incomplete_dir;
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/* For stacking mounts, if true, this indicates if the incomplete dir
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* needs to be freed for this SB. Similar to mi_index_free */
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bool mi_incomplete_free;
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const struct cred *mi_owner;
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struct mount_options mi_options;
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/* This mutex is to be taken before create, rename, delete */
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struct mutex mi_dir_struct_mutex;
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/*
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* A queue of waiters who want to be notified about new pending reads.
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*/
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wait_queue_head_t mi_pending_reads_notif_wq;
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/*
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* Protects - RCU safe:
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* - reads_list_head
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* - mi_pending_reads_count
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* - mi_last_pending_read_number
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* - data_file_segment.reads_list_head
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*/
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spinlock_t pending_read_lock;
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/* List of active pending_read objects */
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struct list_head mi_reads_list_head;
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/* Total number of items in reads_list_head */
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int mi_pending_reads_count;
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/*
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* Last serial number that was assigned to a pending read.
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* 0 means no pending reads have been seen yet.
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*/
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int mi_last_pending_read_number;
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/* Temporary buffer for read logger. */
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struct read_log mi_log;
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/* SELinux needs special xattrs on our pseudo files */
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struct mem_range pseudo_file_xattr[PSEUDO_FILE_COUNT];
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/* A queue of waiters who want to be notified about blocks_written */
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wait_queue_head_t mi_blocks_written_notif_wq;
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/* Number of blocks written since mount */
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atomic_t mi_blocks_written;
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/* Per UID read timeouts */
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spinlock_t mi_per_uid_read_timeouts_lock;
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struct incfs_per_uid_read_timeouts *mi_per_uid_read_timeouts;
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int mi_per_uid_read_timeouts_size;
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/* zstd workspace */
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struct mutex mi_zstd_workspace_mutex;
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void *mi_zstd_workspace;
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ZSTD_DStream *mi_zstd_stream;
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struct delayed_work mi_zstd_cleanup_work;
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/* sysfs node */
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struct incfs_sysfs_node *mi_sysfs_node;
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/* Last error information */
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struct mutex mi_le_mutex;
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incfs_uuid_t mi_le_file_id;
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u64 mi_le_time_us;
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u32 mi_le_page;
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u32 mi_le_errno;
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uid_t mi_le_uid;
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/* Number of reads timed out */
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u32 mi_reads_failed_timed_out;
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/* Number of reads failed because hash verification failed */
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u32 mi_reads_failed_hash_verification;
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/* Number of reads failed for another reason */
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u32 mi_reads_failed_other;
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/* Number of reads delayed because page had to be fetched */
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u32 mi_reads_delayed_pending;
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/* Total time waiting for pages to be fetched */
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u64 mi_reads_delayed_pending_us;
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/*
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* Number of reads delayed because of per-uid min_time_us or
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* min_pending_time_us settings
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*/
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u32 mi_reads_delayed_min;
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/* Total time waiting because of per-uid min_time_us or
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* min_pending_time_us settings.
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*
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* Note that if a read is initially delayed because we have to wait for
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* the page, then further delayed because of min_pending_time_us
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* setting, this counter gets incremented by only the further delay
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* time.
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*/
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u64 mi_reads_delayed_min_us;
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};
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struct data_file_block {
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loff_t db_backing_file_data_offset;
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size_t db_stored_size;
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enum incfs_compression_alg db_comp_alg;
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};
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struct pending_read {
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incfs_uuid_t file_id;
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s64 timestamp_us;
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atomic_t done;
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int block_index;
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int serial_number;
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uid_t uid;
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struct list_head mi_reads_list;
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struct list_head segment_reads_list;
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struct rcu_head rcu;
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};
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struct data_file_segment {
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wait_queue_head_t new_data_arrival_wq;
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/* Protects reads and writes from the blockmap */
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struct rw_semaphore rwsem;
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/* List of active pending_read objects belonging to this segment */
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/* Protected by mount_info.pending_reads_mutex */
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struct list_head reads_list_head;
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};
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/*
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* Extra info associated with a file. Just a few bytes set by a user.
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*/
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struct file_attr {
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loff_t fa_value_offset;
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size_t fa_value_size;
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u32 fa_crc;
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};
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struct data_file {
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struct backing_file_context *df_backing_file_context;
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struct mount_info *df_mount_info;
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incfs_uuid_t df_id;
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/*
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* Array of segments used to reduce lock contention for the file.
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* Segment is chosen for a block depends on the block's index.
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*/
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struct data_file_segment df_segments[SEGMENTS_PER_FILE];
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/* Base offset of the first metadata record. */
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loff_t df_metadata_off;
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/* Base offset of the block map. */
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loff_t df_blockmap_off;
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/* File size in bytes */
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loff_t df_size;
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/* File header flags */
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u32 df_header_flags;
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/* File size in DATA_FILE_BLOCK_SIZE blocks */
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int df_data_block_count;
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/* Total number of blocks, data + hash */
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int df_total_block_count;
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/* For mapped files, the offset into the actual file */
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loff_t df_mapped_offset;
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/* Number of data blocks written to file */
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atomic_t df_data_blocks_written;
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/* Number of data blocks in the status block */
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u32 df_initial_data_blocks_written;
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/* Number of hash blocks written to file */
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atomic_t df_hash_blocks_written;
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/* Number of hash blocks in the status block */
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u32 df_initial_hash_blocks_written;
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/* Offset to status metadata header */
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loff_t df_status_offset;
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/*
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* Mutex acquired while enabling verity. Note that df_hash_tree is set
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* by enable verity.
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*
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* The backing file mutex bc_mutex may be taken while this mutex is
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* held.
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*/
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struct mutex df_enable_verity;
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/*
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* Set either at construction time or during enabling verity. In the
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* latter case, set via smp_store_release, so use smp_load_acquire to
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* read it.
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*/
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struct mtree *df_hash_tree;
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/* Guaranteed set if df_hash_tree is set. */
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struct incfs_df_signature *df_signature;
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/*
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* The verity file digest, set when verity is enabled and the file has
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* been opened
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*/
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struct mem_range df_verity_file_digest;
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struct incfs_df_verity_signature *df_verity_signature;
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};
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struct dir_file {
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struct mount_info *mount_info;
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struct file *backing_dir;
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};
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struct inode_info {
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struct mount_info *n_mount_info; /* A mount, this file belongs to */
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struct inode *n_backing_inode;
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struct data_file *n_file;
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struct inode n_vfs_inode;
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};
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struct dentry_info {
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struct path backing_path;
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};
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enum FILL_PERMISSION {
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CANT_FILL = 0,
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CAN_FILL = 1,
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};
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struct incfs_file_data {
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/* Does this file handle have INCFS_IOC_FILL_BLOCKS permission */
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enum FILL_PERMISSION fd_fill_permission;
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/* If INCFS_IOC_GET_FILLED_BLOCKS has been called, where are we */
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int fd_get_block_pos;
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/* And how many filled blocks are there up to that point */
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int fd_filled_data_blocks;
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int fd_filled_hash_blocks;
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};
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struct mount_info *incfs_alloc_mount_info(struct super_block *sb,
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struct mount_options *options,
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struct path *backing_dir_path);
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int incfs_realloc_mount_info(struct mount_info *mi,
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struct mount_options *options);
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void incfs_free_mount_info(struct mount_info *mi);
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char *file_id_to_str(incfs_uuid_t id);
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struct dentry *incfs_lookup_dentry(struct dentry *parent, const char *name);
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struct data_file *incfs_open_data_file(struct mount_info *mi, struct file *bf);
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void incfs_free_data_file(struct data_file *df);
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struct dir_file *incfs_open_dir_file(struct mount_info *mi, struct file *bf);
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void incfs_free_dir_file(struct dir_file *dir);
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struct incfs_read_data_file_timeouts {
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u32 min_time_us;
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u32 min_pending_time_us;
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u32 max_pending_time_us;
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};
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ssize_t incfs_read_data_file_block(struct mem_range dst, struct file *f,
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int index, struct mem_range tmp,
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struct incfs_read_data_file_timeouts *timeouts);
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ssize_t incfs_read_merkle_tree_blocks(struct mem_range dst,
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struct data_file *df, size_t offset);
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int incfs_get_filled_blocks(struct data_file *df,
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struct incfs_file_data *fd,
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struct incfs_get_filled_blocks_args *arg);
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int incfs_read_file_signature(struct data_file *df, struct mem_range dst);
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int incfs_process_new_data_block(struct data_file *df,
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struct incfs_fill_block *block, u8 *data);
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int incfs_process_new_hash_block(struct data_file *df,
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struct incfs_fill_block *block, u8 *data);
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bool incfs_fresh_pending_reads_exist(struct mount_info *mi, int last_number);
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/*
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* Collects pending reads and saves them into the array (reads/reads_size).
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* Only reads with serial_number > sn_lowerbound are reported.
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* Returns how many reads were saved into the array.
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*/
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int incfs_collect_pending_reads(struct mount_info *mi, int sn_lowerbound,
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struct incfs_pending_read_info *reads,
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struct incfs_pending_read_info2 *reads2,
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int reads_size, int *new_max_sn);
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int incfs_collect_logged_reads(struct mount_info *mi,
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struct read_log_state *start_state,
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struct incfs_pending_read_info *reads,
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struct incfs_pending_read_info2 *reads2,
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int reads_size);
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struct read_log_state incfs_get_log_state(struct mount_info *mi);
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int incfs_get_uncollected_logs_count(struct mount_info *mi,
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const struct read_log_state *state);
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static inline struct inode_info *get_incfs_node(struct inode *inode)
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{
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if (!inode)
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return NULL;
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if (inode->i_sb->s_magic != INCFS_MAGIC_NUMBER) {
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/* This inode doesn't belong to us. */
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pr_warn_once("incfs: %s on an alien inode.", __func__);
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return NULL;
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}
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return container_of(inode, struct inode_info, n_vfs_inode);
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}
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static inline struct data_file *get_incfs_data_file(struct file *f)
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{
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struct inode_info *node = NULL;
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if (!f)
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return NULL;
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if (!S_ISREG(f->f_inode->i_mode))
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return NULL;
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node = get_incfs_node(f->f_inode);
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if (!node)
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return NULL;
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return node->n_file;
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}
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static inline struct dir_file *get_incfs_dir_file(struct file *f)
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{
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if (!f)
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return NULL;
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if (!S_ISDIR(f->f_inode->i_mode))
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return NULL;
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return (struct dir_file *)f->private_data;
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}
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/*
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* Make sure that inode_info.n_file is initialized and inode can be used
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* for reading and writing data from/to the backing file.
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*/
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int make_inode_ready_for_data_ops(struct mount_info *mi,
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struct inode *inode,
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struct file *backing_file);
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static inline struct dentry_info *get_incfs_dentry(const struct dentry *d)
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{
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if (!d)
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return NULL;
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return (struct dentry_info *)d->d_fsdata;
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}
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static inline void get_incfs_backing_path(const struct dentry *d,
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struct path *path)
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{
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struct dentry_info *di = get_incfs_dentry(d);
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if (!di) {
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*path = (struct path) {};
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return;
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}
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*path = di->backing_path;
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path_get(path);
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}
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static inline int get_blocks_count_for_size(u64 size)
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{
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if (size == 0)
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return 0;
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return 1 + (size - 1) / INCFS_DATA_FILE_BLOCK_SIZE;
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}
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#endif /* _INCFS_DATA_MGMT_H */
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