docs: filesystems: convert mount_api.txt to ReST
- Add a SPDX header; - Adjust document and section titles; - Some whitespace fixes and new line breaks; - Mark literal blocks as such; - Add table markups; - Add lists markups; - Add it to filesystems/index.rst. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/32332c1659a28c22561cb5e64162c959856066b4.1588021877.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This commit is contained in:
Mauro Carvalho Chehab
Jonathan Corbet
Родитель
a02dcdf65b
Коммит
791a17ee19
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@ -30,6 +30,7 @@ algorithms work.
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files
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locks
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mandatory-locking
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mount_api
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automount-support
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@ -1,8 +1,10 @@
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====================
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FILESYSTEM MOUNT API
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====================
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.. SPDX-License-Identifier: GPL-2.0
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CONTENTS
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====================
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fILESYSTEM Mount API
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====================
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.. CONTENTS
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(1) Overview.
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@ -21,8 +23,7 @@ CONTENTS
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(8) Parameter helper functions.
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========
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OVERVIEW
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Overview
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========
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The creation of new mounts is now to be done in a multistep process:
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@ -43,7 +44,7 @@ The creation of new mounts is now to be done in a multistep process:
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(7) Destroy the context.
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To support this, the file_system_type struct gains two new fields:
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To support this, the file_system_type struct gains two new fields::
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int (*init_fs_context)(struct fs_context *fc);
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const struct fs_parameter_description *parameters;
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@ -57,12 +58,11 @@ Note that security initialisation is done *after* the filesystem is called so
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that the namespaces may be adjusted first.
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======================
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THE FILESYSTEM CONTEXT
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The Filesystem context
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======================
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The creation and reconfiguration of a superblock is governed by a filesystem
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context. This is represented by the fs_context structure:
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context. This is represented by the fs_context structure::
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struct fs_context {
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const struct fs_context_operations *ops;
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@ -86,78 +86,106 @@ context. This is represented by the fs_context structure:
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The fs_context fields are as follows:
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(*) const struct fs_context_operations *ops
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* ::
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const struct fs_context_operations *ops
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These are operations that can be done on a filesystem context (see
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below). This must be set by the ->init_fs_context() file_system_type
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operation.
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(*) struct file_system_type *fs_type
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* ::
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struct file_system_type *fs_type
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A pointer to the file_system_type of the filesystem that is being
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constructed or reconfigured. This retains a reference on the type owner.
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(*) void *fs_private
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* ::
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void *fs_private
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A pointer to the file system's private data. This is where the filesystem
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will need to store any options it parses.
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(*) struct dentry *root
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* ::
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struct dentry *root
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A pointer to the root of the mountable tree (and indirectly, the
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superblock thereof). This is filled in by the ->get_tree() op. If this
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is set, an active reference on root->d_sb must also be held.
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(*) struct user_namespace *user_ns
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(*) struct net *net_ns
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* ::
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struct user_namespace *user_ns
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struct net *net_ns
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There are a subset of the namespaces in use by the invoking process. They
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retain references on each namespace. The subscribed namespaces may be
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replaced by the filesystem to reflect other sources, such as the parent
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mount superblock on an automount.
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(*) const struct cred *cred
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* ::
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const struct cred *cred
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The mounter's credentials. This retains a reference on the credentials.
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(*) char *source
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* ::
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char *source
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This specifies the source. It may be a block device (e.g. /dev/sda1) or
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something more exotic, such as the "host:/path" that NFS desires.
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(*) char *subtype
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* ::
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char *subtype
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This is a string to be added to the type displayed in /proc/mounts to
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qualify it (used by FUSE). This is available for the filesystem to set if
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desired.
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(*) void *security
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* ::
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void *security
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A place for the LSMs to hang their security data for the superblock. The
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relevant security operations are described below.
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(*) void *s_fs_info
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* ::
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void *s_fs_info
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The proposed s_fs_info for a new superblock, set in the superblock by
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sget_fc(). This can be used to distinguish superblocks.
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(*) unsigned int sb_flags
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(*) unsigned int sb_flags_mask
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* ::
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unsigned int sb_flags
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unsigned int sb_flags_mask
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Which bits SB_* flags are to be set/cleared in super_block::s_flags.
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(*) unsigned int s_iflags
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* ::
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unsigned int s_iflags
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These will be bitwise-OR'd with s->s_iflags when a superblock is created.
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(*) enum fs_context_purpose
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* ::
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enum fs_context_purpose
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This indicates the purpose for which the context is intended. The
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available values are:
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FS_CONTEXT_FOR_MOUNT, -- New superblock for explicit mount
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FS_CONTEXT_FOR_SUBMOUNT -- New automatic submount of extant mount
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FS_CONTEXT_FOR_RECONFIGURE -- Change an existing mount
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========================== ======================================
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FS_CONTEXT_FOR_MOUNT, New superblock for explicit mount
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FS_CONTEXT_FOR_SUBMOUNT New automatic submount of extant mount
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FS_CONTEXT_FOR_RECONFIGURE Change an existing mount
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========================== ======================================
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The mount context is created by calling vfs_new_fs_context() or
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vfs_dup_fs_context() and is destroyed with put_fs_context(). Note that the
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@ -176,11 +204,10 @@ mount context. For instance, NFS might pin the appropriate protocol version
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module.
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=================================
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THE FILESYSTEM CONTEXT OPERATIONS
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The Filesystem Context Operations
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=================================
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The filesystem context points to a table of operations:
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The filesystem context points to a table of operations::
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struct fs_context_operations {
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void (*free)(struct fs_context *fc);
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@ -195,24 +222,32 @@ The filesystem context points to a table of operations:
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These operations are invoked by the various stages of the mount procedure to
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manage the filesystem context. They are as follows:
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(*) void (*free)(struct fs_context *fc);
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* ::
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void (*free)(struct fs_context *fc);
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Called to clean up the filesystem-specific part of the filesystem context
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when the context is destroyed. It should be aware that parts of the
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context may have been removed and NULL'd out by ->get_tree().
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(*) int (*dup)(struct fs_context *fc, struct fs_context *src_fc);
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* ::
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int (*dup)(struct fs_context *fc, struct fs_context *src_fc);
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Called when a filesystem context has been duplicated to duplicate the
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filesystem-private data. An error may be returned to indicate failure to
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do this.
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[!] Note that even if this fails, put_fs_context() will be called
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.. Warning::
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Note that even if this fails, put_fs_context() will be called
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immediately thereafter, so ->dup() *must* make the
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filesystem-private data safe for ->free().
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(*) int (*parse_param)(struct fs_context *fc,
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struct struct fs_parameter *param);
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* ::
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int (*parse_param)(struct fs_context *fc,
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struct struct fs_parameter *param);
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Called when a parameter is being added to the filesystem context. param
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points to the key name and maybe a value object. VFS-specific options
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@ -224,7 +259,9 @@ manage the filesystem context. They are as follows:
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If successful, 0 should be returned or a negative error code otherwise.
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(*) int (*parse_monolithic)(struct fs_context *fc, void *data);
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* ::
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int (*parse_monolithic)(struct fs_context *fc, void *data);
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Called when the mount(2) system call is invoked to pass the entire data
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page in one go. If this is expected to be just a list of "key[=val]"
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@ -236,7 +273,9 @@ manage the filesystem context. They are as follows:
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finds it's the standard key-val list then it may pass it off to
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generic_parse_monolithic().
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(*) int (*get_tree)(struct fs_context *fc);
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* ::
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int (*get_tree)(struct fs_context *fc);
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Called to get or create the mountable root and superblock, using the
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information stored in the filesystem context (reconfiguration goes via a
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@ -249,7 +288,9 @@ manage the filesystem context. They are as follows:
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The phase on a userspace-driven context will be set to only allow this to
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be called once on any particular context.
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(*) int (*reconfigure)(struct fs_context *fc);
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* ::
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int (*reconfigure)(struct fs_context *fc);
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Called to effect reconfiguration of a superblock using information stored
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in the filesystem context. It may detach any resources it desires from
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@ -259,19 +300,20 @@ manage the filesystem context. They are as follows:
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On success it should return 0. In the case of an error, it should return
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a negative error code.
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[NOTE] reconfigure is intended as a replacement for remount_fs.
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.. Note:: reconfigure is intended as a replacement for remount_fs.
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===========================
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FILESYSTEM CONTEXT SECURITY
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Filesystem context Security
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===========================
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The filesystem context contains a security pointer that the LSMs can use for
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building up a security context for the superblock to be mounted. There are a
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number of operations used by the new mount code for this purpose:
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(*) int security_fs_context_alloc(struct fs_context *fc,
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struct dentry *reference);
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* ::
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int security_fs_context_alloc(struct fs_context *fc,
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struct dentry *reference);
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Called to initialise fc->security (which is preset to NULL) and allocate
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any resources needed. It should return 0 on success or a negative error
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@ -283,22 +325,28 @@ number of operations used by the new mount code for this purpose:
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non-NULL in the case of a submount (FS_CONTEXT_FOR_SUBMOUNT) in which case
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it indicates the automount point.
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(*) int security_fs_context_dup(struct fs_context *fc,
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struct fs_context *src_fc);
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* ::
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int security_fs_context_dup(struct fs_context *fc,
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struct fs_context *src_fc);
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Called to initialise fc->security (which is preset to NULL) and allocate
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any resources needed. The original filesystem context is pointed to by
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src_fc and may be used for reference. It should return 0 on success or a
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negative error code on failure.
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(*) void security_fs_context_free(struct fs_context *fc);
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* ::
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void security_fs_context_free(struct fs_context *fc);
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Called to clean up anything attached to fc->security. Note that the
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contents may have been transferred to a superblock and the pointer cleared
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during get_tree.
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(*) int security_fs_context_parse_param(struct fs_context *fc,
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struct fs_parameter *param);
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* ::
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int security_fs_context_parse_param(struct fs_context *fc,
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struct fs_parameter *param);
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Called for each mount parameter, including the source. The arguments are
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as for the ->parse_param() method. It should return 0 to indicate that
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@ -310,7 +358,9 @@ number of operations used by the new mount code for this purpose:
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(provided the value pointer is NULL'd out). If it is stolen, 1 must be
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returned to prevent it being passed to the filesystem.
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(*) int security_fs_context_validate(struct fs_context *fc);
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* ::
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int security_fs_context_validate(struct fs_context *fc);
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Called after all the options have been parsed to validate the collection
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as a whole and to do any necessary allocation so that
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@ -320,36 +370,43 @@ number of operations used by the new mount code for this purpose:
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In the case of reconfiguration, the target superblock will be accessible
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via fc->root.
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(*) int security_sb_get_tree(struct fs_context *fc);
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* ::
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int security_sb_get_tree(struct fs_context *fc);
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Called during the mount procedure to verify that the specified superblock
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is allowed to be mounted and to transfer the security data there. It
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should return 0 or a negative error code.
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(*) void security_sb_reconfigure(struct fs_context *fc);
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* ::
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void security_sb_reconfigure(struct fs_context *fc);
|
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Called to apply any reconfiguration to an LSM's context. It must not
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fail. Error checking and resource allocation must be done in advance by
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the parameter parsing and validation hooks.
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(*) int security_sb_mountpoint(struct fs_context *fc, struct path *mountpoint,
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unsigned int mnt_flags);
|
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* ::
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|
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int security_sb_mountpoint(struct fs_context *fc,
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struct path *mountpoint,
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unsigned int mnt_flags);
|
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Called during the mount procedure to verify that the root dentry attached
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to the context is permitted to be attached to the specified mountpoint.
|
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It should return 0 on success or a negative error code on failure.
|
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|
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|
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==========================
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VFS FILESYSTEM CONTEXT API
|
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VFS Filesystem context API
|
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==========================
|
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There are four operations for creating a filesystem context and one for
|
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destroying a context:
|
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(*) struct fs_context *fs_context_for_mount(
|
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struct file_system_type *fs_type,
|
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unsigned int sb_flags);
|
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* ::
|
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|
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struct fs_context *fs_context_for_mount(struct file_system_type *fs_type,
|
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unsigned int sb_flags);
|
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Allocate a filesystem context for the purpose of setting up a new mount,
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whether that be with a new superblock or sharing an existing one. This
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|
@ -359,7 +416,9 @@ destroying a context:
|
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fs_type specifies the filesystem type that will manage the context and
|
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sb_flags presets the superblock flags stored therein.
|
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|
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(*) struct fs_context *fs_context_for_reconfigure(
|
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* ::
|
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|
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struct fs_context *fs_context_for_reconfigure(
|
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struct dentry *dentry,
|
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unsigned int sb_flags,
|
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unsigned int sb_flags_mask);
|
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|
|
@ -369,7 +428,9 @@ destroying a context:
|
|||
configured. sb_flags and sb_flags_mask indicate which superblock flags
|
||||
need changing and to what.
|
||||
|
||||
(*) struct fs_context *fs_context_for_submount(
|
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* ::
|
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|
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struct fs_context *fs_context_for_submount(
|
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struct file_system_type *fs_type,
|
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struct dentry *reference);
|
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|
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|
|
@ -382,7 +443,9 @@ destroying a context:
|
|||
Note that it's not a requirement that the reference dentry be of the same
|
||||
filesystem type as fs_type.
|
||||
|
||||
(*) struct fs_context *vfs_dup_fs_context(struct fs_context *src_fc);
|
||||
* ::
|
||||
|
||||
struct fs_context *vfs_dup_fs_context(struct fs_context *src_fc);
|
||||
|
||||
Duplicate a filesystem context, copying any options noted and duplicating
|
||||
or additionally referencing any resources held therein. This is available
|
||||
|
|
@ -392,14 +455,18 @@ destroying a context:
|
|||
|
||||
The purpose in the new context is inherited from the old one.
|
||||
|
||||
(*) void put_fs_context(struct fs_context *fc);
|
||||
* ::
|
||||
|
||||
void put_fs_context(struct fs_context *fc);
|
||||
|
||||
Destroy a filesystem context, releasing any resources it holds. This
|
||||
calls the ->free() operation. This is intended to be called by anyone who
|
||||
created a filesystem context.
|
||||
|
||||
[!] filesystem contexts are not refcounted, so this causes unconditional
|
||||
destruction.
|
||||
.. Warning::
|
||||
|
||||
filesystem contexts are not refcounted, so this causes unconditional
|
||||
destruction.
|
||||
|
||||
In all the above operations, apart from the put op, the return is a mount
|
||||
context pointer or a negative error code.
|
||||
|
|
@ -407,8 +474,10 @@ context pointer or a negative error code.
|
|||
For the remaining operations, if an error occurs, a negative error code will be
|
||||
returned.
|
||||
|
||||
(*) int vfs_parse_fs_param(struct fs_context *fc,
|
||||
struct fs_parameter *param);
|
||||
* ::
|
||||
|
||||
int vfs_parse_fs_param(struct fs_context *fc,
|
||||
struct fs_parameter *param);
|
||||
|
||||
Supply a single mount parameter to the filesystem context. This include
|
||||
the specification of the source/device which is specified as the "source"
|
||||
|
|
@ -423,53 +492,64 @@ returned.
|
|||
|
||||
The parameter value is typed and can be one of:
|
||||
|
||||
fs_value_is_flag, Parameter not given a value.
|
||||
fs_value_is_string, Value is a string
|
||||
fs_value_is_blob, Value is a binary blob
|
||||
fs_value_is_filename, Value is a filename* + dirfd
|
||||
fs_value_is_file, Value is an open file (file*)
|
||||
==================== =============================
|
||||
fs_value_is_flag Parameter not given a value
|
||||
fs_value_is_string Value is a string
|
||||
fs_value_is_blob Value is a binary blob
|
||||
fs_value_is_filename Value is a filename* + dirfd
|
||||
fs_value_is_file Value is an open file (file*)
|
||||
==================== =============================
|
||||
|
||||
If there is a value, that value is stored in a union in the struct in one
|
||||
of param->{string,blob,name,file}. Note that the function may steal and
|
||||
clear the pointer, but then becomes responsible for disposing of the
|
||||
object.
|
||||
|
||||
(*) int vfs_parse_fs_string(struct fs_context *fc, const char *key,
|
||||
const char *value, size_t v_size);
|
||||
* ::
|
||||
|
||||
int vfs_parse_fs_string(struct fs_context *fc, const char *key,
|
||||
const char *value, size_t v_size);
|
||||
|
||||
A wrapper around vfs_parse_fs_param() that copies the value string it is
|
||||
passed.
|
||||
|
||||
(*) int generic_parse_monolithic(struct fs_context *fc, void *data);
|
||||
* ::
|
||||
|
||||
int generic_parse_monolithic(struct fs_context *fc, void *data);
|
||||
|
||||
Parse a sys_mount() data page, assuming the form to be a text list
|
||||
consisting of key[=val] options separated by commas. Each item in the
|
||||
list is passed to vfs_mount_option(). This is the default when the
|
||||
->parse_monolithic() method is NULL.
|
||||
|
||||
(*) int vfs_get_tree(struct fs_context *fc);
|
||||
* ::
|
||||
|
||||
int vfs_get_tree(struct fs_context *fc);
|
||||
|
||||
Get or create the mountable root and superblock, using the parameters in
|
||||
the filesystem context to select/configure the superblock. This invokes
|
||||
the ->get_tree() method.
|
||||
|
||||
(*) struct vfsmount *vfs_create_mount(struct fs_context *fc);
|
||||
* ::
|
||||
|
||||
struct vfsmount *vfs_create_mount(struct fs_context *fc);
|
||||
|
||||
Create a mount given the parameters in the specified filesystem context.
|
||||
Note that this does not attach the mount to anything.
|
||||
|
||||
|
||||
===========================
|
||||
SUPERBLOCK CREATION HELPERS
|
||||
Superblock Creation Helpers
|
||||
===========================
|
||||
|
||||
A number of VFS helpers are available for use by filesystems for the creation
|
||||
or looking up of superblocks.
|
||||
|
||||
(*) struct super_block *
|
||||
sget_fc(struct fs_context *fc,
|
||||
int (*test)(struct super_block *sb, struct fs_context *fc),
|
||||
int (*set)(struct super_block *sb, struct fs_context *fc));
|
||||
* ::
|
||||
|
||||
struct super_block *
|
||||
sget_fc(struct fs_context *fc,
|
||||
int (*test)(struct super_block *sb, struct fs_context *fc),
|
||||
int (*set)(struct super_block *sb, struct fs_context *fc));
|
||||
|
||||
This is the core routine. If test is non-NULL, it searches for an
|
||||
existing superblock matching the criteria held in the fs_context, using
|
||||
|
|
@ -482,10 +562,12 @@ or looking up of superblocks.
|
|||
|
||||
The following helpers all wrap sget_fc():
|
||||
|
||||
(*) int vfs_get_super(struct fs_context *fc,
|
||||
enum vfs_get_super_keying keying,
|
||||
int (*fill_super)(struct super_block *sb,
|
||||
struct fs_context *fc))
|
||||
* ::
|
||||
|
||||
int vfs_get_super(struct fs_context *fc,
|
||||
enum vfs_get_super_keying keying,
|
||||
int (*fill_super)(struct super_block *sb,
|
||||
struct fs_context *fc))
|
||||
|
||||
This creates/looks up a deviceless superblock. The keying indicates how
|
||||
many superblocks of this type may exist and in what manner they may be
|
||||
|
|
@ -515,14 +597,14 @@ PARAMETER DESCRIPTION
|
|||
=====================
|
||||
|
||||
Parameters are described using structures defined in linux/fs_parser.h.
|
||||
There's a core description struct that links everything together:
|
||||
There's a core description struct that links everything together::
|
||||
|
||||
struct fs_parameter_description {
|
||||
const struct fs_parameter_spec *specs;
|
||||
const struct fs_parameter_enum *enums;
|
||||
};
|
||||
|
||||
For example:
|
||||
For example::
|
||||
|
||||
enum {
|
||||
Opt_autocell,
|
||||
|
|
@ -539,10 +621,12 @@ For example:
|
|||
|
||||
The members are as follows:
|
||||
|
||||
(1) const struct fs_parameter_specification *specs;
|
||||
(1) ::
|
||||
|
||||
const struct fs_parameter_specification *specs;
|
||||
|
||||
Table of parameter specifications, terminated with a null entry, where the
|
||||
entries are of type:
|
||||
entries are of type::
|
||||
|
||||
struct fs_parameter_spec {
|
||||
const char *name;
|
||||
|
|
@ -558,6 +642,7 @@ The members are as follows:
|
|||
|
||||
The 'type' field indicates the desired value type and must be one of:
|
||||
|
||||
======================= ======================= =====================
|
||||
TYPE NAME EXPECTED VALUE RESULT IN
|
||||
======================= ======================= =====================
|
||||
fs_param_is_flag No value n/a
|
||||
|
|
@ -573,19 +658,23 @@ The members are as follows:
|
|||
fs_param_is_blockdev Blockdev path * Needs lookup
|
||||
fs_param_is_path Path * Needs lookup
|
||||
fs_param_is_fd File descriptor result->int_32
|
||||
======================= ======================= =====================
|
||||
|
||||
Note that if the value is of fs_param_is_bool type, fs_parse() will try
|
||||
to match any string value against "0", "1", "no", "yes", "false", "true".
|
||||
|
||||
Each parameter can also be qualified with 'flags':
|
||||
|
||||
======================= ================================================
|
||||
fs_param_v_optional The value is optional
|
||||
fs_param_neg_with_no result->negated set if key is prefixed with "no"
|
||||
fs_param_neg_with_empty result->negated set if value is ""
|
||||
fs_param_deprecated The parameter is deprecated.
|
||||
======================= ================================================
|
||||
|
||||
These are wrapped with a number of convenience wrappers:
|
||||
|
||||
======================= ===============================================
|
||||
MACRO SPECIFIES
|
||||
======================= ===============================================
|
||||
fsparam_flag() fs_param_is_flag
|
||||
|
|
@ -602,9 +691,10 @@ The members are as follows:
|
|||
fsparam_bdev() fs_param_is_blockdev
|
||||
fsparam_path() fs_param_is_path
|
||||
fsparam_fd() fs_param_is_fd
|
||||
======================= ===============================================
|
||||
|
||||
all of which take two arguments, name string and option number - for
|
||||
example:
|
||||
example::
|
||||
|
||||
static const struct fs_parameter_spec afs_param_specs[] = {
|
||||
fsparam_flag ("autocell", Opt_autocell),
|
||||
|
|
@ -618,10 +708,12 @@ The members are as follows:
|
|||
of arguments to specify the type and the flags for anything that doesn't
|
||||
match one of the above macros.
|
||||
|
||||
(2) const struct fs_parameter_enum *enums;
|
||||
(2) ::
|
||||
|
||||
const struct fs_parameter_enum *enums;
|
||||
|
||||
Table of enum value names to integer mappings, terminated with a null
|
||||
entry. This is of type:
|
||||
entry. This is of type::
|
||||
|
||||
struct fs_parameter_enum {
|
||||
u8 opt;
|
||||
|
|
@ -630,7 +722,7 @@ The members are as follows:
|
|||
};
|
||||
|
||||
Where the array is an unsorted list of { parameter ID, name }-keyed
|
||||
elements that indicate the value to map to, e.g.:
|
||||
elements that indicate the value to map to, e.g.::
|
||||
|
||||
static const struct fs_parameter_enum afs_param_enums[] = {
|
||||
{ Opt_bar, "x", 1},
|
||||
|
|
@ -648,18 +740,19 @@ CONFIG_VALIDATE_FS_PARSER=y) and will allow the description to be queried from
|
|||
userspace using the fsinfo() syscall.
|
||||
|
||||
|
||||
==========================
|
||||
PARAMETER HELPER FUNCTIONS
|
||||
Parameter Helper Functions
|
||||
==========================
|
||||
|
||||
A number of helper functions are provided to help a filesystem or an LSM
|
||||
process the parameters it is given.
|
||||
|
||||
(*) int lookup_constant(const struct constant_table tbl[],
|
||||
const char *name, int not_found);
|
||||
* ::
|
||||
|
||||
int lookup_constant(const struct constant_table tbl[],
|
||||
const char *name, int not_found);
|
||||
|
||||
Look up a constant by name in a table of name -> integer mappings. The
|
||||
table is an array of elements of the following type:
|
||||
table is an array of elements of the following type::
|
||||
|
||||
struct constant_table {
|
||||
const char *name;
|
||||
|
|
@ -669,9 +762,11 @@ process the parameters it is given.
|
|||
If a match is found, the corresponding value is returned. If a match
|
||||
isn't found, the not_found value is returned instead.
|
||||
|
||||
(*) bool validate_constant_table(const struct constant_table *tbl,
|
||||
size_t tbl_size,
|
||||
int low, int high, int special);
|
||||
* ::
|
||||
|
||||
bool validate_constant_table(const struct constant_table *tbl,
|
||||
size_t tbl_size,
|
||||
int low, int high, int special);
|
||||
|
||||
Validate a constant table. Checks that all the elements are appropriately
|
||||
ordered, that there are no duplicates and that the values are between low
|
||||
|
|
@ -682,16 +777,20 @@ process the parameters it is given.
|
|||
If all is good, true is returned. If the table is invalid, errors are
|
||||
logged to dmesg and false is returned.
|
||||
|
||||
(*) bool fs_validate_description(const struct fs_parameter_description *desc);
|
||||
* ::
|
||||
|
||||
bool fs_validate_description(const struct fs_parameter_description *desc);
|
||||
|
||||
This performs some validation checks on a parameter description. It
|
||||
returns true if the description is good and false if it is not. It will
|
||||
log errors to dmesg if validation fails.
|
||||
|
||||
(*) int fs_parse(struct fs_context *fc,
|
||||
const struct fs_parameter_description *desc,
|
||||
struct fs_parameter *param,
|
||||
struct fs_parse_result *result);
|
||||
* ::
|
||||
|
||||
int fs_parse(struct fs_context *fc,
|
||||
const struct fs_parameter_description *desc,
|
||||
struct fs_parameter *param,
|
||||
struct fs_parse_result *result);
|
||||
|
||||
This is the main interpreter of parameters. It uses the parameter
|
||||
description to look up a parameter by key name and to convert that to an
|
||||
|
|
@ -711,14 +810,16 @@ process the parameters it is given.
|
|||
parameter is matched, but the value is erroneous, -EINVAL will be
|
||||
returned; otherwise the parameter's option number will be returned.
|
||||
|
||||
(*) int fs_lookup_param(struct fs_context *fc,
|
||||
struct fs_parameter *value,
|
||||
bool want_bdev,
|
||||
struct path *_path);
|
||||
* ::
|
||||
|
||||
int fs_lookup_param(struct fs_context *fc,
|
||||
struct fs_parameter *value,
|
||||
bool want_bdev,
|
||||
struct path *_path);
|
||||
|
||||
This takes a parameter that carries a string or filename type and attempts
|
||||
to do a path lookup on it. If the parameter expects a blockdev, a check
|
||||
is made that the inode actually represents one.
|
||||
|
||||
Returns 0 if successful and *_path will be set; returns a negative error
|
||||
code if not.
|
||||
Returns 0 if successful and ``*_path`` will be set; returns a negative
|
||||
error code if not.
|
||||
|
|
@ -85,7 +85,7 @@ struct p_log {
|
|||
* Superblock creation fills in ->root whereas reconfiguration begins with this
|
||||
* already set.
|
||||
*
|
||||
* See Documentation/filesystems/mount_api.txt
|
||||
* See Documentation/filesystems/mount_api.rst
|
||||
*/
|
||||
struct fs_context {
|
||||
const struct fs_context_operations *ops;
|
||||
|
|
|
|||
|
|
@ -77,7 +77,7 @@
|
|||
* state. This is called immediately after commit_creds().
|
||||
*
|
||||
* Security hooks for mount using fs_context.
|
||||
* [See also Documentation/filesystems/mount_api.txt]
|
||||
* [See also Documentation/filesystems/mount_api.rst]
|
||||
*
|
||||
* @fs_context_dup:
|
||||
* Allocate and attach a security structure to sc->security. This pointer
|
||||
|
|
|
|||
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