RepoMirrors/ceph
1
0
Fork 0
mirror of https://github.com/ceph/ceph synced 2025-03-30 07:19:14 +00:00
Code Issues Packages Projects Releases Wiki Activity

Merge pull request #44116 from lxbsz/caps_doc1

Browse Source 
doc: fix the style of the cephfs capability doc

Reviewed-by: Venky Shankar <vshankar@redhat.com>
This commit is contained in:
Venky Shankar 2021-12-01 14:31:18 +05:30 committed by GitHub
commit 675e4219a5
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 47 additions and 43 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

90
doc/cephfs/capabilities.rst
View File

@ -80,21 +80,21 @@ Abilities granted by each cap
While that is how capabilities are granted (and communicated), the important While that is how capabilities are granted (and communicated), the important
bit is what they actually allow the client to do: bit is what they actually allow the client to do:
* PIN: this just pins the inode into memory. This is sufficient to allow the * **PIN**: this just pins the inode into memory. This is sufficient to allow
client to get to the inode number, as well as other immutable things like the client to get to the inode number, as well as other immutable things like
major or minor numbers in a device inode, or symlink contents. major or minor numbers in a device inode, or symlink contents.
* AUTH: this grants the ability to get to the authentication-related metadata. * **AUTH**: this grants the ability to get to the authentication-related metadata.
In particular, the owner, group and mode. Note that doing a full permission In particular, the owner, group and mode. Note that doing a full permission
check may require getting at ACLs as well, which are stored in xattrs. check may require getting at ACLs as well, which are stored in xattrs.
* LINK: the link count of the inode * **LINK**: the link count of the inode
* XATTR: ability to access or manipulate xattrs. Note that since ACLs are * **XATTR**: ability to access or manipulate xattrs. Note that since ACLs are
stored in xattrs, it's also sometimes necessary to access them when checking stored in xattrs, it's also sometimes necessary to access them when checking
permissions. permissions.
* FILE: this is the big one. These allow the client to access and manipulate * **FILE**: this is the big one. These allow the client to access and manipulate
file data. It also covers certain metadata relating to file data -- the file data. It also covers certain metadata relating to file data -- the
size, mtime, atime and ctime, in particular. size, mtime, atime and ctime, in particular.
@ -130,49 +130,53 @@ it will fail. The loner client will always get all the capabilities.
The filelock will control files' partial metadatas' and the file contents' access The filelock will control files' partial metadatas' and the file contents' access
permissions. The metadatas include **mtime**, **atime**, **size**, etc. permissions. The metadatas include **mtime**, **atime**, **size**, etc.
**Fs**: Once a client has it, all other clients are denied **Fw**. * **Fs**: Once a client has it, all other clients are denied **Fw**.
**Fx**: Only the loner client is allowed this capability. Once the lock state transitions * **Fx**: Only the loner client is allowed this capability. Once the lock state
to LOCK_EXCL, the loner client is granted this along with all other file capabilities transitions to LOCK_EXCL, the loner client is granted this along with all other
except the **Fl**. file capabilities except the **Fl**.
**Fr**: Once a client has it, the **Fb** capability will be already revoked from all * **Fr**: Once a client has it, the **Fb** capability will be already revoked from
the other clients. all the other clients.
If clients only request to read the file, the lock state will be transferred If clients only request to read the file, the lock state will be transferred
to LOCK_SYNC stable state directly. All the clients can be granted **Fscrl** to LOCK_SYNC stable state directly. All the clients can be granted **Fscrl**
capabilities from the auth MDS and **Fscr** capabilities from the replica MDSes. capabilities from the auth MDS and **Fscr** capabilities from the replica MDSes.
If multiple clients read from and write to the same file, then the lock state If multiple clients read from and write to the same file, then the lock state
will be transferred to LOCK_MIX stable state finally and all the clients could will be transferred to LOCK_MIX stable state finally and all the clients could
have the **Frwl** capabilities from the auth MDS, and the **Fr** from the replica have the **Frwl** capabilities from the auth MDS, and the **Fr** from the replica
MDSes. The **Fcb** capabilities won't be granted to all the clients and the MDSes. The **Fcb** capabilities won't be granted to all the clients and the
clients will do sync read/write. clients will do sync read/write.
**Fw**: If there is no loner client and once a client have this capability, the **Fsxcb** * **Fw**: If there is no loner client and once a client have this capability, the
capabilities won't be granted to other clients. **Fsxcb** capabilities won't be granted to other clients.
If multiple clients read from and write to the same file, then the lock state If multiple clients read from and write to the same file, then the lock state
will be transferred to LOCK_MIX stable state finally and all the clients could will be transferred to LOCK_MIX stable state finally and all the clients could
have the **Frwl** capabilities from the auth MDS, and the **Fr** from the replica have the **Frwl** capabilities from the auth MDS, and the **Fr** from the replica
MDSes. The **Fcb** capabilities won't be granted to all the clients and the MDSes. The **Fcb** capabilities won't be granted to all the clients and the
clients will do sync read/write. clients will do sync read/write.
**Fc**: This capability means the clients could cache file read and should be issued * **Fc**: This capability means the clients could cache file read and should be
together with **Fr** capability and only in this use case will it make sense. issued together with **Fr** capability and only in this use case will it make
While actually in some stable or interim transitional states they tend to keep sense.
the **Fc** allowed even the **Fr** capability isn't granted as this can avoid
forcing clients to drop full caches, for example on a simple file size extension
or truncating use case.
**Fb**: This capability means the clients could buffer file write and should be issued While actually in some stable or interim transitional states they tend to keep
together with **Fw** capability and only in this use case will it make sense. the **Fc** allowed even the **Fr** capability isn't granted as this can avoid
While actually in some stable or interim transitional states they tend to keep forcing clients to drop full caches, for example on a simple file size extension
the **Fc** allowed even the **Fw** capability isn't granted as this can avoid or truncating use case.
forcing clients to drop dirty buffers, for example on a simple file size extension
or truncating use case.
**Fl**: This capability means the clients could perform lazy io. LazyIO relaxes POSIX * **Fb**: This capability means the clients could buffer file write and should be
semantics. Buffered reads/writes are allowed even when a file is opened by multiple issued together with **Fw** capability and only in this use case will it make
applications on multiple clients. Applications are responsible for managing cache sense.
coherency themselves.
While actually in some stable or interim transitional states they tend to keep
the **Fc** allowed even the **Fw** capability isn't granted as this can avoid
forcing clients to drop dirty buffers, for example on a simple file size extension
or truncating use case.
* **Fl**: This capability means the clients could perform lazy io. LazyIO relaxes
POSIX semantics. Buffered reads/writes are allowed even when a file is opened by
multiple applications on multiple clients. Applications are responsible for managing
cache coherency themselves.