歡迎來到Linux教程網
Linux教程網
Linux教程網
Linux教程網
您现在的位置: Linux教程網 >> UnixLinux >  >> Linux綜合 >> Linux資訊 >> 更多Linux

linux bible 第十五章 Linux核心數據結構

  第十五章 Linux核心數據結構 本章列出了Linux實用的主要數據結構。 block_dev_strUCt 此結構用於向核心登記塊設備,它還被buffer cache實用。所有此類結構都位於blk_dev數組中。 struct blk_dev_struct { void (*request_fn)(void); struct request * current_request; struct request plug; struct tq_struct plug_tq; }; buffer_head 此結構包含關於buffer cache中一塊緩存的信息。 /* bh state bits */ #define BH_Uptodate 0 /* 1 if the buffer contains valid data */ #define BH_Dirty 1 /* 1 if the buffer is dirty */ #define BH_Lock 2 /* 1 if the buffer is locked */ #define BH_Req 3 /* 0 if the buffer has been invalidated */ #define BH_Touched 4 /* 1 if the buffer has been touched (aging) */ #define BH_Has_aged 5 /* 1 if the buffer has been aged (aging) */ #define BH_Protected 6 /* 1 if the buffer is protected */ #define BH_FreeOnIO 7 /* 1 to discard the buffer_head after IO */ struct buffer_head { /* First cache line: */ unsigned long b_blocknr; /* block number */ kdev_t b_dev; /* device (B_FREE = free) */ kdev_t b_rdev; /* Real device */ unsigned long b_rsector; /* Real buffer location on disk */ struct buffer_head *b_next; /* Hash queue list */ struct buffer_head *b_this_page; /* circular list of buffers in one page */ /* Second cache line: */ unsigned long b_state; /* buffer state bitmap (above) */ struct buffer_head *b_next_free; unsigned int b_count; /* users using this block */ unsigned long b_size; /* block size */ /* Non-performance-critical data follows. */ char *b_data; /* pointer to data block */ unsigned int b_list; /* List that this buffer appears */ unsigned long b_flushtime; /* Time when this (dirty) buffer * should be written */ unsigned long b_lru_time; /* Time when this buffer was * last used. */ struct wait_queue *b_wait; struct buffer_head *b_prev; /* doubly linked hash list */ struct buffer_head *b_prev_free; /* doubly linked list of buffers */ struct buffer_head *b_reqnext; /* request queue */ }; device 系統中每個網絡設備都用一個設備數據結構來表示。 struct device { /* * This is the first field of the "visible" part of this structure * (i.e. as seen by users in the "Space.c" file). It is the name * the interface. */ char *name; /* I/O specific fields */ unsigned long rmem_end; /* shmem "recv" end */


unsigned long rmem_start; /* shmem "recv" start */ unsigned long mem_end; /* shared mem end */ unsigned long mem_start; /* shared mem start */ unsigned long base_addr; /* device I/O address */ unsigned char irq; /* device IRQ number */ /* Low-level status flags. */ volatile unsigned char start, /* start an operation */ interrupt; /* interrupt arrived */ unsigned long tbusy; /* transmitter busy */ struct device *next; /* The device initialization function. Called only once. */ int (*init)(struct device *dev); /* Some hardware also needs these fields, but they are not part of the usual set specified in Space.c. */ unsigned char if_port; /* Selectable AUI,TP, */ unsigned char dma; /* DMA channel */ struct enet_statistics* (*get_stats)(struct device *dev); /* * This marks the end of the "visible" part of the structure. All * fields hereafter are internal to the system, and may change at * will (read: may be cleaned up at will). */ /* These may be needed for future network-power-down code. */ unsigned long trans_start; /* Time (jiffies) of last transmit */ unsigned long last_rx; /* Time of last Rx */ unsigned short flags; /* interface flags (BSD)*/ unsigned short family; /* address family ID */ unsigned short metric; /* routing metric */ unsigned short mtu; /* MTU value */ unsigned short type; /* hardware type */ unsigned short hard_header_len; /* hardware hdr len */ void *priv; /* private data */ /* Interface address info. */ unsigned char broadcast[MAX_ADDR_LEN]; unsigned char pad; unsigned char dev_addr[MAX_ADDR_LEN]; unsigned char addr_len; /* hardware addr len */ unsigned long pa_addr; /* protocol address */ unsigned long pa_brdaddr; /* protocol broadcast addr*/ unsigned long pa_dstaddr; /* protocol P-P other addr*/ unsigned long pa_mask; /* protocol netmask */ unsigned short pa_alen; /* protocol address len */ struct dev_mc_list *mc_list; /* Mcast mac addrs */ int mc_count; /* No installed mcasts */ struct ip_mc_list *ip_mc_list; /* IP mcast filter chain */ __u32 tx_queue_len; /* Max frames per queue */ /* For load balancing driver pair support */ unsigned long pkt_queue; /* Packets queued */ struct device *slave; /* Slave device */ struct net_alias_info *alias_info; /* main dev alias info */ struct net_alias *my_alias; /* alias devs */ /* Pointer to the interface buffers. */ struct sk_buff_head buffs[DEV_NUMBUFFS]; /* Pointers to interface service routines. */ int (*open)(struct device *dev); int (*stop)(struct device *dev);

int (*hard_start_xmit) (struct sk_buff *skb, struct device *dev); int (*hard_header) (struct sk_buff *skb, struct device *dev, unsigned short type, void *daddr, void *saddr, unsigned len); int (*rebuild_header)(void *eth, struct device *dev, unsigned long raddr, struct sk_buff *skb); void (*set_multicast_list)(struct device *dev); int (*set_mac_address)(struct device *dev, void *addr); int (*do_ioctl)(struct device *dev, struct ifreq *ifr, int cmd); int (*set_config)(struct device *dev, struct ifmap *map); void (*header_cache_bind)(struct hh_cache **hhp, struct device *dev, unsigned short htype, __u32 daddr); void (*header_cache_update)(struct hh_cache *hh, struct device *dev, unsigned char * haddr); int (*change_mtu)(struct device *dev, int new_mtu); struct iw_statistics* (*get_wireless_stats)(struct device *dev); }; device_struct 此結構被塊設備和字符設備用來向核心登記(包含設備名稱以及可對此設備進行的 文件操作)。chrdevs和blkdevs中的每個有效分別表示一個字符設備和塊設備。 struct device_struct { const char * name; struct file_operations * fops; }; file 每個打開的文件、套接口都用此結構表示。 struct file { mode_t f_mode; loff_t f_pos; unsigned short f_flags; unsigned short f_count; unsigned long f_reada, f_ramax, f_raend, f_ralen, f_rawin; struct file *f_next, *f_prev; int f_owner; /* pid or -pgrp where SIGIO should be sent */ struct inode * f_inode; struct file_operations * f_op; unsigned long f_version; void *private_data; /* needed for tty driver, and maybe others */ }; files_struct 描敘被某進程打開的所有文件。 struct files_struct { int count; fd_set close_on_exec; fd_set open_fds; struct file * fd[NR_OPEN]; }; fs_struct struct fs_struct { int count; unsigned short umask; struct inode * root, * pwd; }; gendisk 包含關於某個硬盤的信息。用於磁盤初始化



unsigned short f_flags; unsigned short f_count; unsigned long f_reada, f_ramax, f_raend, f_ralen, f_rawin; struct file *f_next, *f_prev; int f_owner; /* pid or -pgrp where SIGIO should be sent */ struct inode * f_inode; struct file_operations * f_op; unsigned long f_version; void *private_data; /* needed for tty driver, and maybe others */ }; files_struct 描敘被某進程打開的所有文件。 struct files_struct { int count; fd_set close_on_exec; fd_set open_fds; struct file * fd[NR_OPEN]; }; fs_struct struct fs_struct { int count; unsigned short umask; struct inode * root, * pwd; }; gendisk 包含關於某個硬盤的信息。用於磁盤初始化



fd_set open_fds; struct file * fd[NR_OPEN]; }; fs_struct struct fs_struct { int count; unsigned short umask; struct inode * root, * pwd; }; gendisk 包含關於某個硬盤的信息。用於磁盤初始化



Copyright © Linux教程網 All Rights Reserved