summaryrefslogtreecommitdiff
path: root/Documentation/filesystems
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/Locking24
-rw-r--r--Documentation/filesystems/vfs.txt45
2 files changed, 48 insertions, 21 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index d30fb2cb5066..f56b39ee2e54 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -61,10 +61,7 @@ prototypes:
int (*get_acl)(struct inode *, int);
int (*setattr) (struct dentry *, struct iattr *);
int (*getattr) (struct vfsmount *, struct dentry *, struct kstat *);
- int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
- ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
ssize_t (*listxattr) (struct dentry *, char *, size_t);
- int (*removexattr) (struct dentry *, const char *);
int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start, u64 len);
void (*update_time)(struct inode *, struct timespec *, int);
int (*atomic_open)(struct inode *, struct dentry *,
@@ -91,15 +88,13 @@ setattr: yes
permission: no (may not block if called in rcu-walk mode)
get_acl: no
getattr: no
-setxattr: yes
-getxattr: no
listxattr: no
-removexattr: yes
fiemap: no
update_time: no
atomic_open: yes
tmpfile: no
+
Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on
victim.
cross-directory ->rename() and rename2() has (per-superblock)
@@ -108,6 +103,23 @@ victim.
See Documentation/filesystems/directory-locking for more detailed discussion
of the locking scheme for directory operations.
+----------------------- xattr_handler operations -----------------------
+prototypes:
+ bool (*list)(struct dentry *dentry);
+ int (*get)(const struct xattr_handler *handler, struct dentry *dentry,
+ struct inode *inode, const char *name, void *buffer,
+ size_t size);
+ int (*set)(const struct xattr_handler *handler, struct dentry *dentry,
+ struct inode *inode, const char *name, const void *buffer,
+ size_t size, int flags);
+
+locking rules:
+ all may block
+ i_mutex(inode)
+list: no
+get: no
+set: yes
+
--------------------------- super_operations ---------------------------
prototypes:
struct inode *(*alloc_inode)(struct super_block *sb);
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index cbec006e10e4..43ef86c266ec 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -323,6 +323,35 @@ Whoever sets up the inode is responsible for filling in the "i_op" field. This
is a pointer to a "struct inode_operations" which describes the methods that
can be performed on individual inodes.
+struct xattr_handlers
+---------------------
+
+On filesystems that support extended attributes (xattrs), the s_xattr
+superblock field points to a NULL-terminated array of xattr handlers. Extended
+attributes are name:value pairs.
+
+ name: Indicates that the handler matches attributes with the specified name
+ (such as "system.posix_acl_access"); the prefix field must be NULL.
+
+ prefix: Indicates that the handler matches all attributes with the specified
+ name prefix (such as "user."); the name field must be NULL.
+
+ list: Determine if attributes matching this xattr handler should be listed
+ for a particular dentry. Used by some listxattr implementations like
+ generic_listxattr.
+
+ get: Called by the VFS to get the value of a particular extended attribute.
+ This method is called by the getxattr(2) system call.
+
+ set: Called by the VFS to set the value of a particular extended attribute.
+ When the new value is NULL, called to remove a particular extended
+ attribute. This method is called by the the setxattr(2) and
+ removexattr(2) system calls.
+
+When none of the xattr handlers of a filesystem match the specified attribute
+name or when a filesystem doesn't support extended attributes, the various
+*xattr(2) system calls return -EOPNOTSUPP.
+
The Inode Object
================
@@ -356,10 +385,7 @@ struct inode_operations {
int (*get_acl)(struct inode *, int);
int (*setattr) (struct dentry *, struct iattr *);
int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *);
- int (*setxattr) (struct dentry *, const char *,const void *,size_t,int);
- ssize_t (*getxattr) (struct dentry *, const char *, void *, size_t);
ssize_t (*listxattr) (struct dentry *, char *, size_t);
- int (*removexattr) (struct dentry *, const char *);
void (*update_time)(struct inode *, struct timespec *, int);
int (*atomic_open)(struct inode *, struct dentry *, struct file *,
unsigned open_flag, umode_t create_mode, int *opened);
@@ -463,19 +489,8 @@ otherwise noted.
getattr: called by the VFS to get attributes of a file. This method
is called by stat(2) and related system calls.
- setxattr: called by the VFS to set an extended attribute for a file.
- Extended attribute is a name:value pair associated with an
- inode. This method is called by setxattr(2) system call.
-
- getxattr: called by the VFS to retrieve the value of an extended
- attribute name. This method is called by getxattr(2) function
- call.
-
listxattr: called by the VFS to list all extended attributes for a
- given file. This method is called by listxattr(2) system call.
-
- removexattr: called by the VFS to remove an extended attribute from
- a file. This method is called by removexattr(2) system call.
+ given file. This method is called by the listxattr(2) system call.
update_time: called by the VFS to update a specific time or the i_version of
an inode. If this is not defined the VFS will update the inode itself