Class: FuseFS::RFuseFS

Inherits:
Object
  • Object
show all
Defined in:
lib/fuse/rfusefs-fuse.rb

Overview

Implements RFuseFS The path supplied to these methods is generally validated by FUSE itself with a prior “getattr” call so we do not revalidate here. sourceforge.net/apps/mediawiki/fuse/index.php?title=FuseInvariants

Constant Summary collapse

CHECK_FILE = 
"/._rfuse_check_"

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(root) ⇒ RFuseFS

Returns a new instance of RFuseFS.



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# File 'lib/fuse/rfusefs-fuse.rb', line 100

def initialize(root)
    @root = root
    @created_files = { }

    # Keep track of changes to file counts and sizes made via Fuse - for #statfs
    @adj_nodes = 0
    @adj_size = 0

    #Define method missing for our filesystem
    #so we can just call all the API methods as required.
    def @root.method_missing(method,*args)
        # our filesystem might implement method_missing itself
        super
    rescue NoMethodError
        DEFAULT_FS.send(method,*args)
    end
end

Class Method Details

.context(ctx, &block) ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 486

def self.context(ctx,&block)
    begin
        Thread.current[:fusefs_reader_uid] = ctx.uid
        Thread.current[:fusefs_reader_gid] = ctx.gid
        yield
    ensure
        Thread.current[:fusefs_reader_uid] = nil
        Thread.current[:fusefs_reader_gid] = nil
    end
end

.method_missing(method, *args) ⇒ Object

Define method missing for our filesystem so we can just call all the API methods as required.



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# File 'lib/fuse/rfusefs-fuse.rb', line 110

def @root.method_missing(method,*args)
    # our filesystem might implement method_missing itself
    super
rescue NoMethodError
    DEFAULT_FS.send(method,*args)
end

Instance Method Details

#flush(ctx, path, ffi) ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 323

def flush(ctx,path,ffi)
    return wrap_context(ctx,__method__,path,ffi) if ctx
    fh = ffi.fh

    if fh && !fh.raw && fh.modified?
        #write contents to the file and mark it unmodified
        @root.write_to(path,fh.flush())
        #if it was created with mknod it now exists in the filesystem...
        @created_files.delete(path)
    end
end

#fsync(ctx, path, datasync, ffi) ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 308

def fsync(ctx,path,datasync,ffi)
    return wrap_context(ctx,__method__,path,datasync,ffi) if ctx
    fh = ffi.fh

    if fh && fh.raw
        if FuseFS::RFUSEFS_COMPATIBILITY
            @root.raw_sync(path,datasync != 0,fh.raw)
        else
            @root.raw_sync(path,datasync != 0)
        end
    else
        flush(nil,path,ffi)
    end
end

#ftruncate(ctx, path, offset, ffi) ⇒ Object

ftruncate - eg called after opening a file for write without append sizes are adjusted at file close



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# File 'lib/fuse/rfusefs-fuse.rb', line 194

def ftruncate(ctx,path,offset,ffi)

    return wrap_context(ctx,__method__,path,offset,ffi) if ctx

    fh = ffi.fh

    if fh.raw
        @root.raw_truncate(path,offset,fh.raw)
        if (offset <= 0)
            fh.contents = ""
        else
            fh.contents = fh.contents[0..offset]
        end
    end
end

#getattr(ctx, path) ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 134

def getattr(ctx,path)

    return wrap_context(ctx,__method__,path) if ctx

    uid = Process.uid
    gid = Process.gid

    if  path == "/" || @root.directory?(path)
        #set "w" flag based on can_mkdir? || can_write? to path + "/._rfuse_check"
        write_test_path = (path == "/" ? "" : path) + CHECK_FILE

        mode = (@root.can_mkdir?(write_test_path) || @root.can_write?(write_test_path)) ? 0777 : 0555
        atime,mtime,ctime = @root.times(path)
        #nlink is set to 1 because apparently this makes find work.
        return RFuse::Stat.directory(mode,{ :uid => uid, :gid => gid, :nlink => 1, :atime => atime, :mtime => mtime, :ctime => ctime })
    elsif @created_files.has_key?(path)
        return @created_files[path]
    elsif @root.file?(path)
        #Set mode from can_write and executable
        mode = 0444
        mode |= 0222 if @root.can_write?(path)
        mode |= 0111 if @root.executable?(path)
        size = size(path)
        atime,mtime,ctime = @root.times(path)
        return RFuse::Stat.file(mode,{ :uid => uid, :gid => gid, :size => size, :atime => atime, :mtime => mtime, :ctime => ctime })
    else
        raise Errno::ENOENT.new(path)
    end

end

#getxattr(ctx, path, name) ⇒ Object

Raises:

  • (Errno::ENODATA) 


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# File 'lib/fuse/rfusefs-fuse.rb', line 414

def getxattr(ctx,path,name)
    return wrap_context(ctx,__method__,path,name) if ctx
    result = @root.xattr(path)[name]
    raise Errno::ENODATA.new("No attribute #{name}") unless result
    result.to_s
end

#listxattr(ctx, path) ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 421

def listxattr(ctx,path)
    return wrap_context(ctx,__method__,path) if ctx
    @root.xattr(path).keys
end

#mkdir(ctx, path, mode) ⇒ Object

getattr



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# File 'lib/fuse/rfusefs-fuse.rb', line 165

def mkdir(ctx,path,mode)

    return wrap_context(ctx,__method__,path,mode) if ctx

    unless @root.can_mkdir?(path)
        raise Errno::EACCES.new(path)
    end

    @root.mkdir(path)
    @adj_nodes += 1
end

#mknod(ctx, path, mode, major, minor) ⇒ Object

mkdir



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# File 'lib/fuse/rfusefs-fuse.rb', line 177

def mknod(ctx,path,mode,major,minor)

    return wrap_context(ctx,__method__,path,mode,major,minor) if ctx

    unless ((RFuse::Stat::S_IFMT & mode) == RFuse::Stat::S_IFREG ) && @root.can_write?(path)
        raise Errno::EACCES.new(path)
    end

    now = Time.now
    stat = RFuse::Stat.file(mode,{ :uid => Process.uid, :gid => Process.gid, :atime => now, :mtime => now, :ctime => now })

    @created_files[path] = stat
    @adj_nodes += 1
end

#mounted ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 478

def mounted()
    @root.mounted()
end

#open(ctx, path, ffi) ⇒ Object

Open. Create a FileHandler and store in fuse file info This will be returned to us in read/write No O_CREATE (mknod first?), no O_TRUNC (truncate first)



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# File 'lib/fuse/rfusefs-fuse.rb', line 233

def open(ctx,path,ffi)
    return wrap_context(ctx,__method__,path,ffi) if ctx
    fh = FileHandle.new(path,ffi.flags)

    #Save the value return from raw_open to be passed back in raw_read/write etc..
    if (FuseFS::RFUSEFS_COMPATIBILITY)
        fh.raw = @root.raw_open(path,fh.raw_mode,true)
    else
        fh.raw = @root.raw_open(path,fh.raw_mode)
    end

    unless fh.raw
        if fh.rdonly?
            fh.contents = @root.read_file(path)
        elsif fh.writing?
            unless @root.can_write?(path)
                raise Errno::EACCES.new(path)
            end

            if @created_files.has_key?(path)
                fh.create
            else
                if fh.rdwr? || fh.append?
                    fh.contents = @root.read_file(path)
                else #wronly && !append
                    #We should get a truncate 0, but might as well play it safe
                    fh.contents = ""
                end
            end
        else
            raise Errno::ENOPERM.new(path)
        end
    end

    #If we get this far, save our filehandle in the FUSE structure
    ffi.fh=fh
end

#read(ctx, path, size, offset, ffi) ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 271

def read(ctx,path,size,offset,ffi)
    return wrap_context(ctx,__method__,path,size,offset,ffi) if ctx

    fh = ffi.fh

    if fh.raw
        if FuseFS::RFUSEFS_COMPATIBILITY
            return @root.raw_read(path,offset,size,fh.raw)
        else
            return @root.raw_read(path,offset,size)
        end
    elsif offset >= 0
        return fh.read(offset,size)
    else
        #TODO: Raise? what does a negative offset mean
        return ""
    end
rescue EOFError
    return ""
end

#readdir(ctx, path, filler, offset, ffi) ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 118

def readdir(ctx,path,filler,offset,ffi)

    return wrap_context(ctx,__method__,path,filler,offset,ffi) if ctx

    #Always have "." and ".."
    filler.push(".",nil,0)
    filler.push("..",nil,0)

    files = @root.contents(path)

    files.each do | filename |
        filler.push(filename,nil,0)
    end

end

#release(ctx, path, ffi) ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 335

def release(ctx,path,ffi)
    return wrap_context(ctx,__method__,path,ffi) if ctx


    fh = ffi.fh
    if fh && fh.raw
        if (FuseFS::RFUSEFS_COMPATIBILITY)
            @root.raw_close(path,fh.raw)
        else
            @root.raw_close(path)
        end
        # if was handled as raw, then assume the file has now been created (or not)
        @created_files.delete(path)
    else
        # Probably just had flush called, but no harm calling it again
        flush(nil,path,ffi)
    end
end

#removexattr(ctx, path, name) ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 426

def removexattr(ctx,path,name)
    return wrap_context(ctx,__method__,path,name) if ctx
    @root.xattr(path).delete(name)
end

#rename(ctx, from, to) ⇒ Object

def symlink(path,as) end



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# File 'lib/fuse/rfusefs-fuse.rb', line 392

def rename(ctx,from,to)
    return wrap_context(ctx,__method__,from,to) if ctx

    if @root.rename(from,to)
        # nothing to do
    elsif @root.file?(from) && @root.can_write?(to) &&  @root.can_delete?(from)
        contents = @root.read_file(from)
        @root.write_to(to,contents)
        @root.delete(from)
    else
        raise Errno::EACCES.new("Unable to move directory #{from}")
    end
end

#rmdir(ctx, path) ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 380

def rmdir(ctx,path)
    return wrap_context(ctx,__method__,path) if ctx

    unless @root.can_rmdir?(path)
        raise Errno::EACCES.new(path)
    end
    @root.rmdir(path)
end

#setxattr(ctx, path, name, value, flags) ⇒ Object

def link(path,as) end



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# File 'lib/fuse/rfusefs-fuse.rb', line 409

def setxattr(ctx,path,name,value,flags)
    return wrap_context(ctx,__method__,path,name,value,flags) if ctx
    @root.xattr(path)[name]=value
end

#statfs(ctx, path) ⇒ Object

Some random numbers to show with df command bsize preferred block size = 1K unless @root provides something different frsize = bsize (but apparently unused) blocks = total number of blocks bfree = number of free blocks bavail = bfree if mounted -o allow_other files = count of all files ffree - count of free file inode



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# File 'lib/fuse/rfusefs-fuse.rb', line 450

def statfs(ctx,path)
    return wrap_context(ctx,__method__,path) if ctx
    block_size = 1024

    stats = @root.statistics(path)
    case stats
    when Array
        used_space, used_files, total_space, total_files = stats
        used_files ||= 0
        used_space ||= 0
        total_files ||= used_files
        total_space ||= used_space
        result = RFuse::StatVfs.new(
          "bsize" => block_size,
          "frsize" => block_size,
          "blocks" => total_space / block_size,
          "bfree" => (total_space - used_space)/block_size,
          "bavail" => (total_space - used_space)/block_size,
          "files" => total_files,
          "ffree" => (total_files - used_files)
        )
        return result
    else
        #expected to quack like rfuse:statvfs
        return stats
    end
end

#truncate(ctx, path, offset) ⇒ Object

truncate a file outside of open files



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# File 'lib/fuse/rfusefs-fuse.rb', line 211

def truncate(ctx,path,offset)
    return wrap_context(ctx,__method__,path,offset) if ctx

    unless @root.can_write?(path)
        raise Errno::EACESS.new(path)
    end

    current_size = size(path)
    unless @root.raw_truncate(path,offset)
        contents = @root.read_file(path)
        if (offset <= 0)
           @root.write_to(path,"")
        elsif offset < contents.length
            @root.write_to(path,contents[0..offset] )
        end
    end
    @adj_size = @adj_size - current_size + (offset <= 0 ? 0 : offset)
end

#unlink(ctx, path) ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 367

def unlink(ctx,path)
    return wrap_context(ctx,__method__,path) if ctx

    unless @root.can_delete?(path)
        raise Errno::EACCES.new(path)
    end

    @adj_size = @adj_size - size(path)

    @created_files.delete(path)
    @root.delete(path)
end

#unmounted ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 482

def unmounted()
    @root.unmounted()
end

#utime(ctx, path, actime, modtime) ⇒ Object

def chown(path,uid,gid) end



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# File 'lib/fuse/rfusefs-fuse.rb', line 360

def utime(ctx,path,actime,modtime)
    return wrap_context(ctx,__method__,path,actime,modtime) if ctx

    #Touch...
    @root.touch(path,modtime) if @root.respond_to?(:touch)
end

#write(ctx, path, buf, offset, ffi) ⇒ Object 



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# File 'lib/fuse/rfusefs-fuse.rb', line 292

def write(ctx,path,buf,offset,ffi)
    return wrap_context(ctx,__method__,path,buf,offset,ffi) if ctx
    fh = ffi.fh

    if fh.raw
        if FuseFS::RFUSEFS_COMPATIBILITY
            return @root.raw_write(path,offset,buf.length,buf,fh.raw)
        else
            @root.raw_write(path,offset,buf.length,buf)
            return buf.length
        end
    else
        return fh.write(offset,buf)
    end
end