Linux0.11 source code analysis-File System Management-high-speed buffer analysis

Actual physical memory: 1m---4m

Buffer Structure: buffer_head buffer header structure at the low end-buffer block at the high end

The size of the buffer block is the same as that of the Logical Disk;

Buffer Management: idle Buffer Queue (two-way loop list) and hashtable for management

The main functions are as follows: (1) the upper-layer read functions bread, breada, and bread_page are used to read the buffer block. The function parameters are the device number + the logical block number of the data on the device.

(2) search function of the buffer block: getblk mainly aims to search for the buffer blocks corresponding to the previous functions. The main return structure includes a Request Buffer block or an idle buffer block.

(4) The brelse function mainly releases the buffer block.