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| author | Dean Deng <deandeng@google.com> | 2020-01-16 12:33:07 -0800 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2020-01-16 12:56:33 -0800 |
| commit | 07f258497932e53f4651b80a086117ffda843fe3 (patch) | |
| tree | 25d38f5c7d17bf532a3e330bc860b1d2248cbf78 /pkg/p9/file.go | |
| parent | 7b7c31820b83abcfe43f7170eff1f7953f3f27e2 (diff) | |
Plumb getting/setting xattrs through InodeOperations and 9p gofer interfaces.
There was a very bare get/setxattr in the InodeOperations interface. Add
context.Context to both, size to getxattr, and flags to setxattr.
Note that extended attributes are passed around as strings in this
implementation, so size is automatically encoded into the value. Size is
added in getxattr so that implementations can return ERANGE if a value is larger
than can fit in the user-allocated buffer. This prevents us from unnecessarily
passing around an arbitrarily large xattr when the user buffer is actually too
small.
Don't use the existing xattrwalk and xattrcreate messages and define our
own, mainly for the sake of simplicity.
Extended attributes will be implemented in future commits.
PiperOrigin-RevId: 290121300
Diffstat (limited to 'pkg/p9/file.go')
| -rw-r--r-- | pkg/p9/file.go | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/pkg/p9/file.go b/pkg/p9/file.go index 96d1f2a8e..4607cfcdf 100644 --- a/pkg/p9/file.go +++ b/pkg/p9/file.go @@ -89,6 +89,22 @@ type File interface { // On the server, SetAttr has a write concurrency guarantee. SetAttr(valid SetAttrMask, attr SetAttr) error + // GetXattr returns extended attributes of this node. + // + // Size indicates the size of the buffer that has been allocated to hold the + // attribute value. If the value is larger than size, implementations may + // return ERANGE to indicate that the buffer is too small, but they are also + // free to ignore the hint entirely (i.e. the value returned may be larger + // than size). All size checking is done independently at the syscall layer. + // + // TODO(b/127675828): Determine concurrency guarantees once implemented. + GetXattr(name string, size uint64) (string, error) + + // SetXattr sets extended attributes on this node. + // + // TODO(b/127675828): Determine concurrency guarantees once implemented. + SetXattr(name, value string, flags uint32) error + // Allocate allows the caller to directly manipulate the allocated disk space // for the file. See fallocate(2) for more details. Allocate(mode AllocateMode, offset, length uint64) error |