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484 lines
21 KiB
Org Mode
484 lines
21 KiB
Org Mode
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#+TITLE: The New Samba VFS
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#+AUTHOR: Ralph Böhme, SerNet, Samba Team
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#+DATE: {{{modification-time(%Y-%m-%d)}}}
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* The new VFS
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** Summary
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The effort to modernize Samba's VFS interface has reached a major milestone with
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the next release Samba 4.14.
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Starting with version 4.14 Samba provides core infrastructure code that allows
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basing all access to the server's filesystem on file handles and not on
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paths. An example of this is using =fstat()= instead of =stat()=, or
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=SMB_VFS_FSTAT()= instead of =SMB_VFS_STAT()= in Samba parlance.
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Historically Samba's fileserver code had to deal a lot with processing path
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based SMB requests. While the SMB protocol itself has been streamlined to be
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purely handle based starting with SMB2, large parts of infrastructure code
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remains in place that will "degrade" handle based SMB2 requests to path based
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filesystem access.
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In order to fully leverage the handle based nature of the SMB2 protocol we came
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up with a straight forward way to convert this infrastructure code.
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At the core, we introduced a helper function that opens a file handle that only
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serves as a path reference and hence can not be used for any sort of access to
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file data.
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Samba's internal file handle structure is of type =struct files_struct= and all
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variable pointing to objects of such type are typically called =fsp=. Until very
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recently the only function that would open such a file handle and return an fsp
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was =SMB_VFS_CREATE_FILE()=.
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Internally =SMB_VFS_CREATE_FILE()= consisted of processing through Samba's VFS
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open function to open the low level file and then going through Samba's Windows
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NTFS emulation code.
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The key point of the new helper function which is called =openat_pathref_fsp()=
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is that it skips the NTFS emulation logic. Additionally, the handle is
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restricted internally to be only usable as a path reference but not for any sort
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of IO. On Linux this is achieved by using the =O_PATH= =open()= flag, on systems
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without =O_PATH= support other mechanisms are used described in more detail
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below.
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Path processing in Samba typically means processing client supplied paths by
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Samba's core path processing function =filename_convert()= which returs a
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pointer to an object of type =struct smb_filename=. Pointers to such objects are
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then passed around, often passing many layers of code.
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By attaching an =fsp= file handle returned from =openat_pathref_fsp()= to all
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=struct smb_filename= objects returned from =filename_convert()=, the whole
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infrastructure code has immediate access to a file handle and so the large
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infrastructure codebase can be converted to use handle based VFS functions
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whenever VFS access is done in a piecemeal fashion.
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** Samba and O_PATH
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*** Background
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On Linux the =O_PATH= flag to =open()= can be used to open a filehandle on a
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file or directory with interesting properties: [fn:manpage]
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- the file-handle indicates a location in the filesystem tree,
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- no permission checks are done by the kernel on the filesystem object and
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- only operations that act purely at the file descriptor level are allowed.
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The file itself is not opened, and other file operations (e.g., ~read(2)~,
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~write(2)~, ~fchmod(2)~, ~fchown(2)~, ~fgetxattr(2)~, ~ioctl(2)~, ~mmap(2)~) fail
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with the error ~EBADF~.
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The following subset of operations that is relevant to Samba is allowed:
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- ~close(2)~,
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- ~fchdir(2)~, if the file descriptor refers to a directory,
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- ~fstat(2)~,
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- ~fstatfs(2)~ and
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- passing the file descriptor as the dirfd argument of ~openat()~ and the other
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"*at()" system calls. This includes ~linkat(2)~ with AT_EMPTY_PATH (or via
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procfs using AT_SYMLINK_FOLLOW) even if the file is not a directory.
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Opening a file or directory with the ~O_PATH~ flag requires no permissions
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on the object itself (but does require execute permission on the
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directories in the path prefix). By contrast, obtaining a reference to a
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filesystem object by opening it with the ~O_RDONLY~ flag requires that the
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caller have read permission on the object, even when the subsequent
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operation (e.g., ~fchdir(2)~, ~fstat(2)~) does not require read permis‐
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sion on the object.
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If for example Samba receives an SMB request to open a file requesting
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~SEC_FILE_READ_ATTRIBUTE~ access rights because the client wants to read the
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file's metadata from the handle, Samba will have to call ~open()~ with at least
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~O_RDONLY~ access rights.
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*** Usecases for O_PATH in Samba
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The ~O_PATH~ flag is currently not used in Samba. By leveraging this Linux
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specific flags we can avoid permission mismatches as described above.
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Additionally ~O_PATH~ allows basing all filesystem accesses done by the
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fileserver on handle based syscalls by opening all client pathnames with
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~O_PATH~ and consistently using for example ~fstat()~ instead of ~stat()~
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throughout the codebase.
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Subsequent parts of this document will call such file-handles opened with O_PATH
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*path referencing file-handles* or *pathref*s for short.
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*** When to open with O_PATH
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In Samba the decision whether to call POSIX ~open()~ on a client pathname or
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whether to leave the low-level handle at -1 (what we call a stat-open) is based
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on the client requested SMB acccess mask.
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The set of access rights that trigger an ~open()~ includes
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~READ_CONTROL_ACCESS~. As a result, the open() will be done with at least
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~O_RDONLY~. If the filesystem supports NT style ACLs natively (like GPFS or ZFS),
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the filesystem may grant the user requested right ~READ_CONTROL_ACCESS~, but it
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may not grant ~READ_DATA~ (~O_RDONLY~).
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Currently the full set of access rights that trigger opening a file is:
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- FILE_READ_DATA
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- FILE_WRITE_DATA
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- FILE_APPEND_DATA
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- FILE_EXECUTE
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- WRITE_DAC_ACCESS
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- WRITE_OWNER_ACCESS
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- SEC_FLAG_SYSTEM_SECURITY
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- READ_CONTROL_ACCESS
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In the future we can remove the following rights from the list on systems that
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support O_PATH:
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- WRITE_DAC_ACCESS
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- WRITE_OWNER_ACCESS
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- SEC_FLAG_SYSTEM_SECURITY
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- READ_CONTROL_ACCESS
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*** Fallback on systems without O_PATH support
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The code of higher level file-handle consumers must be kept simple and
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streamlined, avoiding special casing the handling of the file-handles opened
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with or without ~O_PATH~. To achieve this, a fallback that allows opening a
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file-handle with the same higher level semantics even if the system doesn't
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support ~O_PATH~ is needed.
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The way this is implemented on such systems is impersonating the root user for
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the ~open()~ syscall. In order to avoid privelege escalations security issues,
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we must carefully control the use these file-handles.
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The low level filehandle is stored in a public struct ~struct file_handle~ that
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is part of the widely used ~struct files_struct~. Consumers used to simply
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access the fd directly by derefencing pointers to ~struct files_struct~.
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In order to guard access to such file-handles we do two things:
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- tag the pathref file-handles and
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- control access to the file-handle by making the structure ~struct
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file_handle~ private, only allowing access with accessor functions that
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implement a security boundary.
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In order to avoid bypassing restrictive permissions on intermediate directories
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of a client path, the root user is only impersonated after changing directory
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to the parent directory of the client requested pathname.
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Two functions can then be used to fetch the low-level system file-handle from a
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~struct files_struct~:
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- ~fsp_get_io_fd(fsp)~: enforces fsp is NOT a pathref file-handle and
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- ~fsp_get_pathref_fd(fsp)~: allows fsp to be either a pathref file-handle or a
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traditional POSIX file-handle opened with O_RDONLY or any other POSIX open
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flag.
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Note that the name ~fsp_get_pathref_fd()~ may sound confusing at first given
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that the fsp can be either a pathref fsp or a "normal/full" fsp, but as any
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full file-handle can be used for IO and as path reference, the name
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correctly reflects the intended usage of the caller.
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*** When to use fsp_get_io_fd() or fsp_get_pathref_fd()
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The general guideline is:
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- if you do something like ~fstat(fd)~, use ~fsp_get_pathref_fd()~,
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- if you do something like ~*at(dirfd, ...)~, use ~fsp_get_pathref_fd()~,
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- if you want to print the fd for example in =DEBUG= messages, use ~fsp_get_pathref_fd()~,
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- if you want to call ~close(fd)~, use ~fsp_get_pathref_fd()~,
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- if you're doing a logical comparison of fd values, use ~fsp_get_pathref_fd()~.
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In any other case use ~fsp_get_io_fd()~.
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[fn:manpage] parts of the following sections copied from man open(2)
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[fn:gitlab] https://gitlab.com/samba-team/devel/samba/-/commits/slow-pathref-wip
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* VFS status quo and remaining work
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** VFS Functions Tables [fn:VFS_API]
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*** Existing VFS Functions
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#+ATTR_HTML: :border 1 :rules all :frame border
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| VFS Function | Group | Status |
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|-----------------------------------+----------+--------|
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| SMB_VFS_AIO_FORCE() | [[fsp][fsp]] | - |
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| SMB_VFS_AUDIT_FILE() | [[Special][Special]] | - |
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| SMB_VFS_BRL_LOCK_WINDOWS() | [[fsp][fsp]] | - |
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| SMB_VFS_BRL_UNLOCK_WINDOWS() | [[fsp][fsp]] | - |
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| SMB_VFS_CHDIR() | [[Path][Path]] | Todo |
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| SMB_VFS_CHFLAGS() | [[Path][Path]] | Todo |
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| SMB_VFS_CHMOD() | [[Path][Path]] | Todo |
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| SMB_VFS_CLOSE() | [[fsp][fsp]] | - |
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| SMB_VFS_CLOSEDIR() | [[fsp][fsp]] | - |
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| SMB_VFS_CONNECT() | [[Disk][Disk]] | - |
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| SMB_VFS_CONNECTPATH() | [[P2px][P2px]] | - |
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| SMB_VFS_CREATE_DFS_PATHAT() | [[NsC][NsC]] | Todo |
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| SMB_VFS_CREATE_FILE() | [[NsC][NsC]] | - |
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| SMB_VFS_DISCONNECT() | [[Disk][Disk]] | - |
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| SMB_VFS_DISK_FREE() | [[Disk][Disk]] | - |
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| SMB_VFS_DURABLE_COOKIE() | [[fsp][fsp]] | - |
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| SMB_VFS_DURABLE_DISCONNECT() | [[fsp][fsp]] | - |
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| SMB_VFS_DURABLE_RECONNECT() | [[fsp][fsp]] | - |
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| SMB_VFS_FALLOCATE() | [[fsp][fsp]] | - |
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| SMB_VFS_FCHMOD() | [[fsp][fsp]] | - |
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| SMB_VFS_FCHOWN() | [[fsp][fsp]] | - |
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| SMB_VFS_FCNTL() | [[fsp][fsp]] | - |
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| SMB_VFS_FDOPENDIR() | [[fsp][fsp]] | - |
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| SMB_VFS_FGET_COMPRESSION() | [[fsp][fsp]] | - |
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| SMB_VFS_FGET_DOS_ATTRIBUTES() | [[fsp][fsp]] | - |
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| SMB_VFS_FGET_NT_ACL() | [[fsp][fsp]] | - |
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| SMB_VFS_FGETXATTR() | [[xpathref][xpathref]] | - |
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| SMB_VFS_FILE_ID_CREATE() | [[Special][Special]] | - |
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| SMB_VFS_FLISTXATTR() | [[xpathref][xpathref]] | - |
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| SMB_VFS_FREMOVEXATTR() | [[xpathref][xpathref]] | - |
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| SMB_VFS_FS_CAPABILITIES() | [[Disk][Disk]] | - |
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| SMB_VFS_FSCTL() | [[fsp][fsp]] | - |
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| SMB_VFS_FSET_DOS_ATTRIBUTES() | [[fsp][fsp]] | - |
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| SMB_VFS_FSET_NT_ACL() | [[fsp][fsp]] | - |
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| SMB_VFS_FSETXATTR() | [[xpathref][xpathref]] | - |
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| SMB_VFS_FS_FILE_ID() | [[Special][Special]] | - |
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| SMB_VFS_FSTAT() | [[fsp][fsp]] | - |
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| SMB_VFS_FSYNC() | [[fsp][fsp]] | - |
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| SMB_VFS_FSYNC_SEND() | [[fsp][fsp]] | - |
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| SMB_VFS_FTRUNCATE() | [[fsp][fsp]] | - |
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| SMB_VFS_GET_ALLOC_SIZE() | [[fsp][fsp]] | - |
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| SMB_VFS_GET_DFS_REFERRALS() | [[Disk][Disk]] | - |
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| SMB_VFS_GET_DOS_ATTRIBUTES_RECV() | [[Enum][Enum]] | - |
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| SMB_VFS_GET_DOS_ATTRIBUTES_SEND() | [[Enum][Enum]] | - |
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| SMB_VFS_GETLOCK() | [[fsp][fsp]] | - |
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| SMB_VFS_GET_NT_ACL_AT() | [[Path][Path]] | Todo |
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| SMB_VFS_GET_QUOTA() | [[Special][Special]] | - |
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| SMB_VFS_GET_REAL_FILENAME() | [[P2px][P2px]] | - |
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| SMB_VFS_GET_SHADOW_COPY_DATA() | [[fsp][fsp]] | - |
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| SMB_VFS_GETWD() | [[Special][Special]] | - |
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| SMB_VFS_GETXATTR() | [[Path][Path]] | Todo |
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| SMB_VFS_GETXATTRAT_RECV() | [[Enum][Enum]] | - |
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| SMB_VFS_GETXATTRAT_SEND() | [[Enum][Enum]] | - |
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| SMB_VFS_KERNEL_FLOCK() | [[fsp][fsp]] | - |
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| SMB_VFS_LCHOWN() | [[Path][Path]] | Todo |
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| SMB_VFS_LINKAT() | [[NsC][NsC]] | Todo |
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| SMB_VFS_LINUX_SETLEASE() | [[fsp][fsp]] | - |
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| SMB_VFS_LISTXATTR() | [[Path][Path]] | Todo |
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| SMB_VFS_LOCK() | [[fsp][fsp]] | - |
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| SMB_VFS_LSEEK() | [[fsp][fsp]] | - |
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| SMB_VFS_LSTAT() | [[Path][Path]] | Todo |
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| SMB_VFS_MKDIRAT() | [[NsC][NsC]] | Todo |
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| SMB_VFS_MKNODAT() | [[NsC][NsC]] | Todo |
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| SMB_VFS_NTIMES() | [[Path][Path]] | Todo |
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| SMB_VFS_OFFLOAD_READ_RECV() | [[fsp][fsp]] | - |
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| SMB_VFS_OFFLOAD_READ_SEND() | [[fsp][fsp]] | - |
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| SMB_VFS_OFFLOAD_WRITE_RECV() | [[fsp][fsp]] | - |
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| SMB_VFS_OFFLOAD_WRITE_SEND() | [[fsp][fsp]] | - |
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| SMB_VFS_OPENAT() | [[NsC][NsC]] | - |
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| SMB_VFS_PREAD() | [[fsp][fsp]] | - |
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| SMB_VFS_PREAD_SEND() | [[fsp][fsp]] | - |
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| SMB_VFS_PWRITE() | [[fsp][fsp]] | - |
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| SMB_VFS_PWRITE_SEND() | [[fsp][fsp]] | - |
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| SMB_VFS_READ_DFS_PATHAT() | [[Symlink][Symlink]] | Todo |
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| SMB_VFS_READDIR() | [[fsp][fsp]] | - |
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| SMB_VFS_READDIR_ATTR() | [[Path][Path]] | Todo |
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| SMB_VFS_READLINKAT() | [[Symlink][Symlink]] | Todo |
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| SMB_VFS_REALPATH() | [[P2px][P2px]] | - |
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| SMB_VFS_RECVFILE() | [[fsp][fsp]] | - |
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| SMB_VFS_REMOVEXATTR() | [[Path][Path]] | Todo |
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| SMB_VFS_RENAMEAT() | [[Path][Path]] | Todo |
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| SMB_VFS_REWINDDIR() | [[fsp][fsp]] | - |
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| SMB_VFS_SEEKDIR() | [[fsp][fsp]] | - |
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| SMB_VFS_SENDFILE() | [[fsp][fsp]] | - |
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| SMB_VFS_SET_COMPRESSION() | [[fsp][fsp]] | - |
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| SMB_VFS_SET_DOS_ATTRIBUTES() | [[Path][Path]] | - |
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| SMB_VFS_SET_QUOTA() | [[Special][Special]] | - |
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| SMB_VFS_SETXATTR() | [[Path][Path]] | Todo |
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| SMB_VFS_SNAP_CHECK_PATH() | [[Disk][Disk]] | - |
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| SMB_VFS_SNAP_CREATE() | [[Disk][Disk]] | - |
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| SMB_VFS_SNAP_DELETE() | [[Disk][Disk]] | - |
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| SMB_VFS_STAT() | [[Path][Path]] | Todo |
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| SMB_VFS_STATVFS() | [[Disk][Disk]] | - |
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| SMB_VFS_STREAMINFO() | [[Path][Path]] | Todo |
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| SMB_VFS_STRICT_LOCK_CHECK() | [[fsp][fsp]] | - |
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| SMB_VFS_SYMLINKAT() | [[NsC][NsC]] | Todo |
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| SMB_VFS_SYS_ACL_BLOB_GET_FD() | [[xpathref][xpathref]] | - |
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| SMB_VFS_SYS_ACL_BLOB_GET_FILE() | [[Path][Path]] | Todo |
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| SMB_VFS_SYS_ACL_DELETE_DEF_FILE() | [[Path][Path]] | Todo |
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| SMB_VFS_SYS_ACL_GET_FD() | [[xpathref][xpathref]] | - |
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| SMB_VFS_SYS_ACL_GET_FILE() | [[Path][Path]] | Todo |
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| SMB_VFS_SYS_ACL_SET_FD() | [[xpathref][xpathref]] | - |
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| SMB_VFS_TELLDIR() | [[fsp][fsp]] | - |
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| SMB_VFS_TRANSLATE_NAME() | [[P2px][P2px]] | - |
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| SMB_VFS_UNLINKAT() | [[NsC][NsC]] | Todo |
|
|||
|
|-----------------------------------+----------+--------|
|
|||
|
|
|||
|
*** New VFS Functions
|
|||
|
#+ATTR_HTML: :border 1 :rules all :frame border
|
|||
|
| VFS Function | Group | Status |
|
|||
|
|---------------------------------+----------+--------|
|
|||
|
| SMB_VFS_SYS_ACL_DELETE_DEF_FD() | [[xpathref][xpathref]] | Todo |
|
|||
|
| SMB_VFS_READDIR_ATTRAT() | [[Enum][Enum]] | Todo |
|
|||
|
| SMB_VFS_STATX() | [[Enum][Enum]] | Todo |
|
|||
|
| SMB_VFS_FUTIMENS() | [[fsp][fsp]] | Todo |
|
|||
|
|---------------------------------+----------+--------|
|
|||
|
|
|||
|
** VFS functions by category
|
|||
|
*** Disk operations <<Disk>>
|
|||
|
- SMB_VFS_CONNECT()
|
|||
|
- SMB_VFS_DISCONNECT()
|
|||
|
- SMB_VFS_DISK_FREE()
|
|||
|
- SMB_VFS_FS_CAPABILITIES()
|
|||
|
- SMB_VFS_GET_DFS_REFERRALS()
|
|||
|
- SMB_VFS_SNAP_CHECK_PATH()
|
|||
|
- SMB_VFS_SNAP_CREATE()
|
|||
|
- SMB_VFS_SNAP_DELETE()
|
|||
|
- SMB_VFS_STATVFS()
|
|||
|
|
|||
|
No changes needed.
|
|||
|
*** Handle based VFS functions <<fsp>>
|
|||
|
- SMB_VFS_AIO_FORCE()
|
|||
|
- SMB_VFS_BRL_LOCK_WINDOWS()
|
|||
|
- SMB_VFS_BRL_UNLOCK_WINDOWS()
|
|||
|
- SMB_VFS_CLOSE()
|
|||
|
- SMB_VFS_CLOSEDIR()
|
|||
|
- SMB_VFS_DURABLE_COOKIE()
|
|||
|
- SMB_VFS_DURABLE_DISCONNECT()
|
|||
|
- SMB_VFS_FALLOCATE()
|
|||
|
- SMB_VFS_FCHMOD()
|
|||
|
- SMB_VFS_FCHOWN()
|
|||
|
- SMB_VFS_FCNTL()
|
|||
|
- SMB_VFS_FDOPENDIR()
|
|||
|
- SMB_VFS_FGET_DOS_ATTRIBUTES()
|
|||
|
- SMB_VFS_FGET_NT_ACL()
|
|||
|
- SMB_VFS_FSCTL()
|
|||
|
- SMB_VFS_FSET_DOS_ATTRIBUTES()
|
|||
|
- SMB_VFS_FSET_NT_ACL()
|
|||
|
- SMB_VFS_FSTAT()
|
|||
|
- SMB_VFS_FSYNC()
|
|||
|
- SMB_VFS_FSYNC_SEND()
|
|||
|
- SMB_VFS_FTRUNCATE()
|
|||
|
- SMB_VFS_GETLOCK()
|
|||
|
- SMB_VFS_GET_ALLOC_SIZE()
|
|||
|
- SMB_VFS_GET_SHADOW_COPY_DATA()
|
|||
|
- SMB_VFS_KERNEL_FLOCK()
|
|||
|
- SMB_VFS_LINUX_SETLEASE()
|
|||
|
- SMB_VFS_LOCK()
|
|||
|
- SMB_VFS_LSEEK()
|
|||
|
- SMB_VFS_OFFLOAD_READ_SEND()
|
|||
|
- SMB_VFS_OFFLOAD_WRITE_SEND()
|
|||
|
- SMB_VFS_PREAD()
|
|||
|
- SMB_VFS_PREAD_SEND()
|
|||
|
- SMB_VFS_PWRITE()
|
|||
|
- SMB_VFS_PWRITE_SEND()
|
|||
|
- SMB_VFS_READDIR()
|
|||
|
- SMB_VFS_RECVFILE()
|
|||
|
- SMB_VFS_REWINDDIR()
|
|||
|
- SMB_VFS_SEEKDIR()
|
|||
|
- SMB_VFS_SENDFILE()
|
|||
|
- SMB_VFS_SET_COMPRESSION()
|
|||
|
- SMB_VFS_STRICT_LOCK_CHECK()
|
|||
|
- SMB_VFS_TELLDIR()
|
|||
|
|
|||
|
If an fsp is provided by the SMB layer we use that, otherwise we use the
|
|||
|
pathref fsp =smb_fname->fsp= provided by =filename_convert()=.
|
|||
|
*** Namespace changing VFS functions <<NsC>>
|
|||
|
|
|||
|
- SMB_VFS_CREATE_FILE()
|
|||
|
|
|||
|
All intermediate VFS calls within =SMB_VFS_CREATE_FILE()= will be based on
|
|||
|
=smb_fname->fsp= if the requested path exists. When creating a file we rely on
|
|||
|
=non_widelink_open()= which doesn't depend on a dirfsp.
|
|||
|
|
|||
|
- SMB_VFS_MKDIRAT()
|
|||
|
|
|||
|
Needs a real dirfsp (done).
|
|||
|
|
|||
|
- SMB_VFS_OPENAT()
|
|||
|
|
|||
|
Is only called from within =non_widelink_open()= with a dirfsp equivalent of
|
|||
|
=AT_FDCWD= and so doesn't need a real dirfsp.
|
|||
|
|
|||
|
The following operations need a real dirfsp:
|
|||
|
|
|||
|
- SMB_VFS_LINKAT()
|
|||
|
- SMB_VFS_MKNODAT()
|
|||
|
- SMB_VFS_RENAMEAT()
|
|||
|
- SMB_VFS_SYMLINKAT()
|
|||
|
- SMB_VFS_UNLINKAT()
|
|||
|
|
|||
|
Callers use =openat_pathref_fsp()= to open a fsp on the parent directory.
|
|||
|
|
|||
|
*** Path based VFS functions <<Path>>
|
|||
|
All path based VFS functtions will be replaced by handle based variants using the
|
|||
|
=smb_fname->fsp= provided by =filename_convert()=.
|
|||
|
|
|||
|
- SMB_VFS_CHDIR()
|
|||
|
- SMB_VFS_CHFLAGS()
|
|||
|
- SMB_VFS_CHMOD()
|
|||
|
- SMB_VFS_DURABLE_RECONNECT()
|
|||
|
- SMB_VFS_GETXATTR()
|
|||
|
- SMB_VFS_GET_COMPRESSION()
|
|||
|
- SMB_VFS_GET_DOS_ATTRIBUTES()
|
|||
|
- SMB_VFS_GET_NT_ACL_AT()
|
|||
|
- SMB_VFS_LCHOWN()
|
|||
|
- SMB_VFS_LISTXATTR()
|
|||
|
- SMB_VFS_LSTAT()
|
|||
|
- SMB_VFS_NTIMES()
|
|||
|
- SMB_VFS_REMOVEXATTR()
|
|||
|
- SMB_VFS_SETXATTR()
|
|||
|
- SMB_VFS_SET_DOS_ATTRIBUTES()
|
|||
|
- SMB_VFS_STAT()
|
|||
|
- SMB_VFS_STREAMINFO()
|
|||
|
- SMB_VFS_SYS_ACL_BLOB_GET_FILE()
|
|||
|
- SMB_VFS_SYS_ACL_DELETE_DEF_FILE()
|
|||
|
- SMB_VFS_SYS_ACL_GET_FILE()
|
|||
|
- SMB_VFS_SYS_ACL_SET_FILE()
|
|||
|
|
|||
|
Replace with corresponding handle based VFS calls.
|
|||
|
*** AT VFS functions that can't be based on handles <<Symlink>>
|
|||
|
|
|||
|
- SMB_VFS_CREATE_DFS_PATHAT()
|
|||
|
- SMB_VFS_READ_DFS_PATHAT()
|
|||
|
- SMB_VFS_READLINKAT()
|
|||
|
|
|||
|
As the DFS link implementation is based on symlinks, we have to use *AT based
|
|||
|
functions with real dirfsps.
|
|||
|
|
|||
|
*** AT VFS functions needed for directory enumeration <<Enum>>
|
|||
|
|
|||
|
- SMB_VFS_GET_DOS_ATTRIBUTES_SEND()
|
|||
|
- SMB_VFS_GETXATTRAT_SEND()
|
|||
|
- SMB_VFS_READDIR_ATTRAT() (NEW)
|
|||
|
- SMB_VFS_STATX() (NEW)
|
|||
|
|
|||
|
We can't open file-handles on all directory children for performance
|
|||
|
reasons. Therefor we need *AT based VFS functions for all metadata VFS queries
|
|||
|
done in the directory enumeration loop.
|
|||
|
|
|||
|
*** Handle based VFS functions not allowed on O_PATH opened handles <<xpathref>>
|
|||
|
- SMB_VFS_FGETXATTR()
|
|||
|
- SMB_VFS_FLISTXATTR()
|
|||
|
- SMB_VFS_FREMOVEXATTR()
|
|||
|
- SMB_VFS_FSETXATTR()
|
|||
|
- SMB_VFS_SYS_ACL_BLOB_GET_FD()
|
|||
|
- SMB_VFS_SYS_ACL_GET_FD()
|
|||
|
- SMB_VFS_SYS_ACL_DELETE_DEF_FD() (NEW)
|
|||
|
- SMB_VFS_SYS_ACL_SET_FD()
|
|||
|
|
|||
|
Based upon securely opening a full fd based on =/proc/self/fd/%d= as in the case
|
|||
|
of xattrs, pathref handles can't be used for xattr IO, and in the case of ACLs
|
|||
|
pathref handles can't be used to access default ACEs.
|
|||
|
*** Pure path to path translation <<P2px>>
|
|||
|
- SMB_VFS_CONNECTPATH()
|
|||
|
- SMB_VFS_GET_REAL_FILENAME()
|
|||
|
- SMB_VFS_REALPATH()
|
|||
|
- SMB_VFS_TRANSLATE_NAME()
|
|||
|
|
|||
|
No changes needed.
|
|||
|
*** Special cases <<Special>>
|
|||
|
- SMB_VFS_FILE_ID_CREATE()
|
|||
|
- SMB_VFS_FS_FILE_ID()
|
|||
|
- SMB_VFS_GET_QUOTA()
|
|||
|
- SMB_VFS_GETWD()
|
|||
|
- SMB_VFS_SET_QUOTA()
|
|||
|
|
|||
|
No changes needed.
|
|||
|
|
|||
|
- SMB_VFS_AUDIT_FILE()
|
|||
|
|
|||
|
This is currently unused.
|
|||
|
|
|||
|
[fn:VFS_API] ~grep 'SMB_VFS_*' source3/include/vfs_macros.h | grep -v NEXT_ | sed 's|.*\(SMB_VFS_.*\)(.*|\1()|' | sort~
|