Linux Study Notes (knowledge point summary)

Superblock: records the overall information of this filesystem, including the total inode/block quantity, usage, remaining amount, and the format and related information of the file system;
Inode: records the attributes of an archive. An archive occupies one inode and records the block number of the archive;
Block: records the content of an object. If the object is too large, multiple blocks are occupied.

 

• Filesystem description)

This section describes the start and end block numbers of each block group, and describes each section (superblock, bitmap, inodemap,
Data Block.

 

• Block Bitmap (Block table)

If you want to add new files, block will always be used! What block do you want to use to record? Of course, we chose an 'empty Block' to record the information of the new archive.
So how do you know that the block is empty? This requires assistance from block bitmap. Which blocks can be learned from block bitmap?
It is empty, so our system can quickly find available space to deal with files.

Similarly, if you delete some files, the block numbers occupied by these files must be released,
In this case, the logo corresponding to the block number in the block bitmpap must be changed to "not in use! This is the bitmap function.

 

• Inode Bitmap (inode table)

This is actually similar to block bitmap, but block bitmap records the use of unused block numbers,
Inode bitmap records the used and unused inode numbers!