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add links to code helpers

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Remzi Arpaci-Dusseau
2021-12-01 20:18:44 -06:00
parent 7c2cd4fdb6
commit 1d62fe10c2
1 changed files with 17 additions and 13 deletions
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filesystems-distributed/README.md
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@@ -24,11 +24,13 @@ your file server will link with it and call its various routines.
## On-Disk File System: A Log-Structured File System ## On-Disk File System: A Log-Structured File System
Your on-disk file system structures should roughly follow that of the Your on-disk file system structures should roughly follow that of the
log-structured file system discussed in class. On-disk, the first structure log-structured file system discussed
should be a singular checkpoint region. The checkpoint region should contain a [here](https://pages.cs.wisc.edu/~remzi/OSTEP/file-lfs.pdf). On-disk,
disk pointer to the current end of the log; it should also contain pointers the first structure should be a singular checkpoint region. The
to pieces of the inode map (assume there are a maximum of 4096 inodes; assume checkpoint region should contain a disk pointer to the current end of
each piece of the inode map has 16 entries). the log; it should also contain pointers to pieces of the inode map
(assume there are a maximum of 4096 inodes; assume each piece of the
inode map has 16 entries).
Other than the checkpoint region, your on-disk image just consists of an Other than the checkpoint region, your on-disk image just consists of an
ever-growing log (i.e., we won't be implementing cleaning). Thus, whenever you ever-growing log (i.e., we won't be implementing cleaning). Thus, whenever you
@@ -60,11 +62,12 @@ that are not yet in use (in an allocated 4-KB directory block), the
inode number should be set to -1. This way, utilities can scan through inode number should be set to -1. This way, utilities can scan through
the entries to check if they are valid. the entries to check if they are valid.
When your server is started, it is passed the name of the file system image When your server is started, it is passed the name of the file system
file. If this file does not exist, the file server should create it, and image file. If this file does not exist, the file server should create
initialize it properly, and force it to disk. Such initialization includes it, and initialize it properly, and force it to disk. Such
creating the checkpoint region, the initial inode map, and creating a single initialization includes creating the checkpoint region, the initial
root directory with proper . and .. entries. The root inode number should be 0. inode map, and creating a single root directory with proper `.` and
`..` entries. The root inode number should be 0.
When booting off of an existing image, your server should read in the When booting off of an existing image, your server should read in the
checkpoint region (and keep an in-memory version of it), as well as the entire checkpoint region (and keep an in-memory version of it), as well as the entire
@@ -124,7 +127,6 @@ Now you might be wondering: why do this? Simple: if the server crashes, the
client can simply timeout and retry the operation and know that it is OK to do client can simply timeout and retry the operation and know that it is OK to do
so. Read this chapter on NFS for details. so. Read this chapter on NFS for details.
Now you might be wondering: how do I implement a timeout? Simple, with the Now you might be wondering: how do I implement a timeout? Simple, with the
`select()` interface. The `select()` calls allows you to wait for a reply `select()` interface. The `select()` calls allows you to wait for a reply
on a certain socket descriptor (or more than one, though that is not needed on a certain socket descriptor (or more than one, though that is not needed
@@ -157,9 +159,11 @@ timeout of some kind (default: five second timeout).
To get you going, we have written some simple UDP code that can send a To get you going, we have written some simple UDP code that can send a
message and then receive a reply from a client to a server. It can be found in message and then receive a reply from a client to a server. It can be found in
the XXX. [here](https://github.com/remzi-arpacidusseau/ostep-code/tree/master/dist-intro).
You'll also have to learn how to make a shared library. Read [here](https://tldp.org/HOWTO/Program-Library-HOWTO/shared-libraries.html) for more information.
How to make a shared library: [here](https://tldp.org/HOWTO/Program-Library-HOWTO/shared-libraries.html)