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![user file
descriptor table file table inode table
0
file[100] inode[100] fd -> inode
am^/etc/passwd)
count D
j Read
u_ofile[15] „
k
0011111
«J ,
inode -> Disk
4.2 STRUCTURE OF A REGULAR FILE 69 j Rd-Wrf
^ (local)
f_inode
Data
Inode Blocks
direct „
(buffers[])
1
i count
1
1
i Write
direct
Figure 5.3. Data Structures after Open
i_addr[8] fdl - open("/etc/passwd", OJRDONLY);
fd2 - open ("local", 0_RDWR);
28
Process -> memory
INTRODUCTION TO THE KERNEL
direct , fd3 - open ("/etc/passwd", OJWRONLY);
per process
Figure 5.3 shows the relationship between the inode table, file table, and user file
direct descriptor data structures. Bach open returns a file descriptor to the process, and
the corresponding entry in the user file descriptor table points to a unique entry in
direct,
direct programmers to encode only two parameters.
u_procp
does not check the third parameter unless the second parameter indicates that it must, allowing
proc[50]
8
direct,
single
indirect p_addr?
double
indirect
coremap[100]?
triple
indirect
Figure 4.6. Direct and Indirect Blocks in Inode](https://image.slidesharecdn.com/lions-20111016-111016004644-phpapp02/85/Lions-3-320.jpg)
Uploaded byRyousei Takano
Lions本読書会合宿成果発表
The document summarizes the data structures used in UNIX version 6 to manage files and file descriptors. It shows how the inode table, file table, and per-process user file descriptor table relate to each other and allow processes to access files via file descriptors. Open system calls return a file descriptor that points to an entry in the user file descriptor table, which then points to an entry in the file table that is associated with an inode from the inode table. This allows each open file to be uniquely represented across all running processes.
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Lions本読書会合宿成果発表
- 1. @oraccha Lions’ Commentary onUNIX 2011 2011 10 16
- 2. •1 •2 10:30 Prezi • ← http://prezi.com/zm2fff4l-ia1/data-structure-of-the-unix-v6/
- 3. user file descriptor table file table inode table 0 file[100] inode[100] fd -> inode am^/etc/passwd) count D j Read u_ofile[15] „ k 0011111 «J , inode -> Disk 4.2 STRUCTURE OF A REGULAR FILE 69 j Rd-Wrf ^ (local) f_inode Data Inode Blocks direct „ (buffers[]) 1 i count 1 1 i Write direct Figure 5.3. Data Structures after Open i_addr[8] fdl - open("/etc/passwd", OJRDONLY); fd2 - open ("local", 0_RDWR); 28 Process -> memory INTRODUCTION TO THE KERNEL direct , fd3 - open ("/etc/passwd", OJWRONLY); per process Figure 5.3 shows the relationship between the inode table, file table, and user file direct descriptor data structures. Bach open returns a file descriptor to the process, and the corresponding entry in the user file descriptor table points to a unique entry in direct, direct programmers to encode only two parameters. u_procp does not check the third parameter unless the second parameter indicates that it must, allowing proc[50] 8 direct, single indirect p_addr? double indirect coremap[100]? triple indirect Figure 4.6. Direct and Indirect Blocks in Inode
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