FUSE
用户态文件系统框架
1. 系统支持FUSE:
FUSE简介:
FUSE 是Linux Kernel的特性之一：
一个用户态文件系统框架，a userspace filesystem framework。
形象的说就是可以在用户态运行一个程序，程序暴露出一个FUSE文件系统，
对这个文件系统进行的读写操作都会被转给用户态的程序处理。
FUSE由内核模块
fuse.ko和用户空间的动态链接库libfuse.*组成，如果要开发使用fuse的用户态程序，需要安装
fuse-devel：yum install fuse-devel
Fuse control filesystem
加载fuse.ko后，可以用下面的命令加载fusectl fs：
mount -t fusectl none /sys/fs/fuse/connections每个使用fuse的进程有一个对应的目录：
$ ls /sys/fs/fuse/connections
38 42fuse提供了 fuse 和 fuseblk 两种文件系统类型，
可以作为mount命令的 -t 参数的参数值, 文档给出的挂载选项：
'fd=N'
The file descriptor to use for communication between the userspace
filesystem and the kernel. The file descriptor must have been
obtained by opening the FUSE device ('/dev/fuse').
'rootmode=M'
The file mode of the filesystem's root in octal representation.
'user_id=N'
The numeric user id of the mount owner.
'group_id=N'
The numeric group id of the mount owner.
'default_permissions'
By default FUSE doesn't check file access permissions, the
filesystem is free to implement its access policy or leave it to
the underlying file access mechanism (e.g. in case of network
filesystems). This option enables permission checking, restricting
access based on file mode. It is usually useful together with the
'allow_other' mount option.
'allow_other'
This option overrides the security measure restricting file access
to the user mounting the filesystem. This option is by default only
allowed to root, but this restriction can be removed with a
(userspace) configuration option.
'max_read=N'
With this option the maximum size of read operations can be set.
The default is infinite. Note that the size of read requests is
limited anyway to 32 pages (which is 128kbyte on i386).
'blksize=N'
Set the block size for the filesystem. The default is 512. This
option is only valid for 'fuseblk' type mounts.mount卸载不掉，多半是权限不够:
tracefs /sys/kernel/debug/tracing tracefs rw,relatime 0 0
tmpfs /run/user/1002 tmpfs rw,nosuid,nodev,relatime,size=6574104k,mode=700,uid=1002,gid=1002 0 0
tmpfs /run/user/1001 tmpfs rw,nosuid,nodev,relatime,size=6574104k,mode=700,uid=1001,gid=1001 0 0
tmpfs /run/user/1000 tmpfs rw,nosuid,nodev,relatime,size=6574104k,mode=700,uid=1000,gid=1000 0 0
block_fs_mount /home/luotang/bfs fuse.block_fs_mount rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other 0 0
luotang@10-23-227-66:~/blockfs$ umount /home/luotang/bfs
umount: /home/luotang/bfs: Transport endpoint is not connected
luotang@10-23-227-66:~/blockfs$ ps aux | grep mount
luotang 486129 0.0 0.0 13144 1024 pts/7 S+ 09:53 0:00 grep --color=auto mount
luotang@10-23-227-66:~/blockfs$ ll /home/luotang/bfs
ls: cannot access '/home/luotang/bfs': Transport endpoint is not connected
luotang@10-23-227-66:~/blockfs$ sudo umount /home/luotang/bfs
tmpfs /run/user/1002 tmpfs rw,nosuid,nodev,relatime,size=6574104k,mode=700,uid=1002,gid=1002 0 0
tmpfs /run/user/1001 tmpfs rw,nosuid,nodev,relatime,size=6574104k,mode=700,uid=1001,gid=1001 0 0
tmpfs /run/user/1000 tmpfs rw,nosuid,nodev,relatime,size=6574104k,mode=700,uid=1000,gid=1000 0 0
luotang@10-23-227-66:~/blockfs$ ^C
luotang@10-23-227-66:~/blockfs$
也可以
Edit /etc/fuse.conf so you never meet the fuse:
bad mount point `/mnt': Transport endpoint is not connected error again
Open it as root with your favorite editor, for example
vim /etc/fuse.conf
luotang@10-23-227-66:~/blockfs$ cat /etc/fuse.conf
# The file /etc/fuse.conf allows for the following parameters:
#
# user_allow_other - Using the allow_other mount option works fine as root, in
# order to have it work as user you need user_allow_other in /etc/fuse.conf as
# well. (This option allows users to use the allow_other option.) You need
# allow_other if you want users other than the owner to access a mounted fuse.
# This option must appear on a line by itself. There is no value, just the
# presence of the option.
#user_allow_other
# mount_max = n - this option sets the maximum number of mounts.
# Currently (2014) it must be typed exactly as shown
# (with a single space before and after the equals sign).
#mount_max = 1000
luotang@10-23-227-66:~/blockfs$
Uncomment the user_allow_other line.2. 使用libfuse挂载用户态文件系统
FUSE开发用户态文件系统接口
把客户端源码克隆到本地:
$ git clone https://github.com/libfuse/libfuse编译libfuse到当前的ubuntu
Once you're strong enough, save the world:
编译libfuse
You can download libfuse from
https://github.com/libfuse/libfuse/releases. To build and install, you
must use [Meson](http://mesonbuild.com/) and
[Ninja](https://ninja-build.org). After extracting the libfuse
tarball, create a (temporary) build directory and run Meson:
$ mkdir build; cd build
$ meson ..
Other way to define install dir:
$ meson --prefix=/usr build
Normally, the default build options will work fine. If you
nevertheless want to adjust them, you can do so with the
*meson configure* command:
$ meson configure # list options
$ meson configure -D disable-mtab=true # set an option
To build, test, and install libfuse, you then use Ninja:
$ ninja
$ sudo python3 -m pytest test/
$ sudo ninja install
Running the tests requires the [py.test](http://www.pytest.org/)
Python module. Instead of running the tests as root, the majority of
tests can also be run as a regular user if *util/fusermount3* is made
setuid root first:
$ sudo chown root:root util/fusermount3
$ sudo chmod 4755 util/fusermount3
$ python3 -m pytest test/BFS中fuse_main的输入参数: argc、argv，命令行参数
挂载参数，有参数值，BFS中设置的参数是:
allow_other,direct_io,entry_timeout=0.5,attr_timeout=0.5,nonemptyBFS中fuse_main的输入参数：op，文件操作函数
fuse_operations 在文件 /usr/include/fuse3/fuse.h 中定义。
static const struct fuse_operations kGlobalUBFSOps = {
.getattr = bfs_getattr,
.readlink = nullptr,
.mknod = nullptr,
.mkdir = bfs_mkdir,
.unlink = bfs_unlink,
.rmdir = bfs_rmdir,
.symlink = nullptr,
.rename = bfs_rename,
.link = nullptr,
.chmod = bfs_chmod,
.chown = bfs_chown,
.truncate = bfs_truncate,
.open = bfs_open,
.read = bfs_read,
.write = bfs_write,
.statfs = bfs_statfs,
.flush = bfs_flush,
.release = bfs_release,
.fsync = bfs_fsync,
.setxattr = nullptr,
.getxattr = nullptr,
.listxattr = nullptr,
.removexattr = nullptr,
.opendir = bfs_opendir,
.readdir = bfs_readdir,
.releasedir = bfs_releasedir,
.fsyncdir = nullptr,
.init = bfs_init,
.destroy = bfs_destroy,
.access = bfs_access,
.create = bfs_create,
.lock = nullptr,
.utimens = nullptr,
.bmap = nullptr,
.ioctl = nullptr,
.poll = nullptr,
.write_buf = nullptr,
.read_buf = nullptr,
.flock = nullptr,
.fallocate = bfs_fallocate,
.copy_file_range = nullptr,
.lseek = bfs_lseek,
};
# 一定要定义这个, 否则新老接口编译会报错
#ifndef HAVE_FUSE3
#define HAVE_FUSE3
#endif
#ifdef HAVE_FUSE3
#ifndef FUSE_USE_VERSION
#define FUSE_USE_VERSION 31
#endif
#else
#ifndef FUSE_USE_VERSION
#define FUSE_USE_VERSION 26
#endif
#endif
if (!fuse_main(nargs, newargv, &kGlobalUBFSOps, &ubfs)) {
ret = EXIT_SUCCESS;
LOG(ERROR) << "fuse mount exit";
}
FUSE版本和支持的命令行参数
luotang@10-23-227-66:~/blockfs/build$ sudo ./app/bfs_mount -V
[876191 20210120 11:06:15.627125Z][INFO][app/bfs_mount.cc:329] FUSE version: 3.10.1
FUSE library version 3.10.1
using FUSE kernel interface version 7.31
fusermount3 version: 3.10.1
[876191 20210120 11:06:15.627930Z][ERROR][app/bfs_mount.cc:362] fuse mount exit
luotang@10-23-227-66:~/blockfs/build$
luotang@10-23-227-66:~/blockfs/build$ sudo ./app/bfs_mount -h
[sudo] password for luotang:
[875750 20210120 11:04:46.009927Z][INFO][app/bfs_mount.cc:329] FUSE version: 3.10.1
usage: ./app/bfs_mount [options] <mountpoint>
FUSE options:
-h --help print help
-V --version print version
-d -o debug enable debug output (implies -f)
-f foreground operation
-s disable multi-threaded operation
-o clone_fd use separate fuse device fd for each thread
(may improve performance)
-o max_idle_threads the maximum number of idle worker threads
allowed (default: 10)
-o kernel_cache cache files in kernel
-o [no]auto_cache enable caching based on modification times (off)
-o umask=M set file permissions (octal)
-o uid=N set file owner
-o gid=N set file group
-o entry_timeout=T cache timeout for names (1.0s)
-o negative_timeout=T cache timeout for deleted names (0.0s)
-o attr_timeout=T cache timeout for attributes (1.0s)
-o ac_attr_timeout=T auto cache timeout for attributes (attr_timeout)
-o noforget never forget cached inodes
-o remember=T remember cached inodes for T seconds (0s)
-o modules=M1[:M2...] names of modules to push onto filesystem stack
-o allow_other allow access by all users
-o allow_root allow access by root
-o auto_unmount auto unmount on process termination
Options for subdir module:
-o subdir=DIR prepend this directory to all paths (mandatory)
-o [no]rellinks transform absolute symlinks to relative
Options for iconv module:
-o from_code=CHARSET original encoding of file names (default: UTF-8)
-o to_code=CHARSET new encoding of the file names (default: UTF-8)
[875750 20210120 11:04:46.010178Z][ERROR][app/bfs_mount.cc:362] fuse mount exit
luotang@10-23-227-66:~/blockfs/build$luotang@10-23-227-66:~/blockfs/build$ sudo ./app/bfs_mount /home/luotang/bfs/
[877654 20210120 11:11:18.315592Z][INFO][app/bfs_mount.cc:329] FUSE version: 3.10.1
Protocol version: 7.27
Capabilities:
FUSE_CAP_WRITEBACK_CACHE
FUSE_CAP_ASYNC_READ
FUSE_CAP_POSIX_LOCKS
FUSE_CAP_ATOMIC_O_TRUNC
FUSE_CAP_EXPORT_SUPPORT
........
[877656 20210120 11:11:20.468840Z][INFO][lib/file_handle.cc:80] read file meta success, free num:99979
[877656 20210120 11:11:20.468858Z][INFO][lib/file_block_handle.cc:14] total file block num: 108388
[877656 20210120 11:11:20.544594Z][INFO][lib/file_block_handle.cc:102] read file block meta success, free num:108367
[877656 20210120 11:11:20.547188Z][WARN][lib/journal_handle.cc:61] load journal success, journal head_: -1 journal tail_: -1 min_seq_no_: 0 max_seq_no_: 0 available_seq_no_: 1
[877656 20210120 11:11:20.547206Z][ERROR][lib/journal_handle.cc:104] I am not master, cannot replay journal
[877656 20210120 11:11:20.547215Z][INFO][lib/super_block.cc:157] UXDB root path: /mnt/mysql/data/
[877656 20210120 11:11:20.547219Z][INFO][lib/super_block.cc:173] mount point has been configured
[877656 20210120 11:11:20.547221Z][INFO][lib/file_store_udisk.cc:1026] create fs mount point: /mnt/mysql/data/
........
[877657 20210120 11:12:59.788906Z][INFO][lib/file_store_udisk.cc:228] open directory: /mnt/mysql/data/
[877657 20210120 11:12:59.788975Z][INFO][lib/dir_handle.cc:615] open directory /mnt/mysql/data/
[877657 20210120 11:12:59.789004Z][INFO][lib/fd_handle.cc:34] current fd pool size: 400000
[877657 20210120 11:12:59.789011Z][INFO][lib/fd_handle.cc:37] current fd: 0 pool size: 399999
[877656 20210120 11:12:59.789075Z][INFO][app/bfs_mount.cc:149] readdir: /mnt/mysql/data/
[877656 20210120 11:12:59.789100Z][INFO][lib/directory.cc:103] scan directory: /mnt/mysql/data/#innodb_temp/
[877656 20210120 11:12:59.789108Z][INFO][lib/directory.cc:103] scan directory: /mnt/mysql/data/luotang/
[877656 20210120 11:12:59.789122Z][INFO][lib/directory.cc:103] scan directory: /mnt/mysql/data/sys/
[877656 20210120 11:12:59.789127Z][INFO][lib/directory.cc:121] scan file: undo_002
[877656 20210120 11:12:59.789132Z][INFO][lib/directory.cc:121] scan file: ib_logfile0
[877656 20210120 11:12:59.789137Z][INFO][lib/directory.cc:121] scan file: ibtmp1
[877656 20210120 11:12:59.789148Z][INFO][lib/directory.cc:121] scan file: ibdata1
[877656 20210120 11:12:59.789153Z][INFO][lib/directory.cc:121] scan file: ib_logfile1
[877656 20210120 11:12:59.789157Z][INFO][lib/directory.cc:121] scan file: mysql.ibd
[877656 20210120 11:12:59.789162Z][INFO][lib/directory.cc:121] scan file: #ib_16384_0.dblwr
[877656 20210120 11:12:59.789166Z][INFO][lib/directory.cc:121] scan file: #ib_16384_1.dblwr
[877656 20210120 11:12:59.789170Z][INFO][lib/directory.cc:121] scan file: undo_001
[877656 20210120 11:12:59.789180Z][INFO][lib/directory.cc:49] 1611112379 2021-01-20 11:12:59
[877656 20210120 11:12:59.789284Z][INFO][lib/file_store_udisk.cc:318] stat path: /mnt/mysql/data/#innodb_temp
[877656 20210120 11:12:59.789294Z][INFO][lib/file_store_udisk.cc:327] stat path: /mnt/mysql/data/#innodb_temp
[877656 20210120 11:12:59.789311Z][INFO][lib/file_handle.cc:694] get created file name: /mnt/mysql/data/#innodb_temp
[877656 20210120 11:12:59.789319Z][INFO][lib/super_block.cc:235] check target path: /mnt/mysql/data/#innodb_tem
........
luotang@10-23-227-66:~$ ll /home/luotang/bfs/
total 4
dr-xr-xr-x 2 root root 0 Jan 1 1970 ./
drwxr-xr-x 19 luotang luotang 4096 Jan 20 03:29 ../
---------- 0 root root 196608 Jan 18 18:45 '#ib_16384_0.dblwr'
---------- 0 root root 8585216 Jan 18 18:45 '#ib_16384_1.dblwr'
---------- 0 root root 12582912 Jan 18 18:45 ibdata1
---------- 0 root root 50331648 Jan 18 18:45 ib_logfile0
---------- 0 root root 50331648 Jan 18 18:45 ib_logfile1
---------- 0 root root 12582912 Jan 18 19:34 ibtmp1
d--------- 0 root root 0 Jan 18 18:47 '#innodb_temp'/
d--------- 0 root root 0 Jan 18 18:47 luotang/
---------- 0 root root 25165824 Jan 18 18:45 mysql.ibd
d--------- 0 root root 0 Jan 18 18:47 sys/
---------- 0 root root 10485760 Jan 18 18:45 undo_001
---------- 0 root root 10485760 Jan 18 18:45 undo_002
luotang@10-23-227-66:~$
查看挂载信息:
fusectl /sys/fs/fuse/connections fusectl rw,relatime 0 0
binfmt_misc /proc/sys/fs/binfmt_misc binfmt_misc rw,relatime 0 0
tracefs /sys/kernel/debug/tracing tracefs rw,relatime 0 0
tmpfs /run/user/1002 tmpfs rw,nosuid,nodev,relatime,size=6574104k,mode=700,uid=1002,gid=1002 0 0
tmpfs /run/user/1001 tmpfs rw,nosuid,nodev,relatime,size=6574104k,mode=700,uid=1001,gid=1001 0 0
tmpfs /run/user/1000 tmpfs rw,nosuid,nodev,relatime,size=6574104k,mode=700,uid=1000,gid=1000 0 0
bfs_mount /home/luotang/bfs fuse.bfs_mount rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other 0 0
luotang@10-23-227-66:~$ cat /proc/mounts
luotang@10-23-227-66:~$ sudo umount /home/luotang/bfs
[sudo] password for luotang:
luotang@10-23-227-66:~$
[877657 20210120 11:12:59.789965Z][INFO][lib/file_handle.cc:135] transformPath dirname: /mnt/mysql/data/
[877657 20210120 11:12:59.789967Z][INFO][lib/file_handle.cc:136] transformPath filename: undo_001
[877657 20210120 11:12:59.790015Z][INFO][lib/dir_handle.cc:657] close directory name: /mnt/mysql/data/ fd: 0
[877654 20210120 11:15:03.637325Z][ERROR][app/bfs_mount.cc:362] fuse mount exit
luotang@10-23-227-66:~/blockfs/build$
luotang@10-23-227-66:~/blockfs/build$
luotang@10-23-227-66:~/blockfs/build$
luotang@10-23-227-66:~/bfs$ ll
total 4
dr-xr-xr-x 2 root root 0 Jan 1 1970 ./
drwxr-xr-x 19 luotang luotang 4096 Jan 20 03:29 ../
---------- 0 root root 196608 Jan 18 18:45 '#ib_16384_0.dblwr'
---------- 0 root root 8585216 Jan 18 18:45 '#ib_16384_1.dblwr'
---------- 0 root root 12582912 Jan 18 18:45 ibdata1
---------- 0 root root 50331648 Jan 18 18:45 ib_logfile0
---------- 0 root root 50331648 Jan 18 18:45 ib_logfile1
---------- 0 root root 12582912 Jan 18 19:34 ibtmp1
d--------- 0 root root 0 Jan 18 18:47 '#innodb_temp'/
d--------- 0 root root 0 Jan 18 18:47 luotang/
---------- 0 root root 25165824 Jan 18 18:45 mysql.ibd
d--------- 0 root root 0 Jan 18 18:47 sys/
---------- 0 root root 10485760 Jan 18 18:45 undo_001
---------- 0 root root 10485760 Jan 18 18:45 undo_002
luotang@10-23-227-66:~/bfs$ rm -f mysql.ibd
luotang@10-23-227-66:~/bfs$ ll
total 4
dr-xr-xr-x 2 root root 0 Jan 1 1970 ./
drwxr-xr-x 19 luotang luotang 4096 Jan 20 03:29 ../
---------- 0 root root 196608 Jan 18 18:45 '#ib_16384_0.dblwr'
---------- 0 root root 8585216 Jan 18 18:45 '#ib_16384_1.dblwr'
---------- 0 root root 12582912 Jan 18 18:45 ibdata1
---------- 0 root root 50331648 Jan 18 18:45 ib_logfile0
---------- 0 root root 50331648 Jan 18 18:45 ib_logfile1
---------- 0 root root 12582912 Jan 18 19:34 ibtmp1
d--------- 0 root root 0 Jan 18 18:47 '#innodb_temp'/
d--------- 0 root root 0 Jan 18 18:47 luotang/
d--------- 0 root root 0 Jan 18 18:47 sys/
---------- 0 root root 10485760 Jan 18 18:45 undo_001
---------- 0 root root 10485760 Jan 18 18:45 undo_002
luotang@10-23-227-66:~/bfs$
[948171 20210120 14:30:23.888888Z][INFO][lib/file_store_udisk.cc:318] stat path: /mnt/mysql/data/mysql.ibd
[948171 20210120 14:30:23.888926Z][INFO][lib/file_store_udisk.cc:327] stat path: /mnt/mysql/data/mysql.ibd
[948171 20210120 14:30:23.888935Z][INFO][lib/file_handle.cc:694] get created file name: /mnt/mysql/data/mysql.ibd
[948171 20210120 14:30:23.888942Z][INFO][lib/super_block.cc:235] check target path: /mnt/mysql/data/mysql.ibd mount point: /mnt/mysql/data/
[948171 20210120 14:30:23.888952Z][INFO][lib/file_handle.cc:135] transformPath dirname: /mnt/mysql/data/
[948171 20210120 14:30:23.888957Z][INFO][lib/file_handle.cc:136] transformPath filename: mysql.ibd
[948170 20210120 14:30:23.889025Z][INFO][lib/file_handle.cc:597] unlink file: /mnt/mysql/data/mysql.ibd
[948170 20210120 14:30:23.889056Z][INFO][lib/super_block.cc:235] check target path: /mnt/mysql/data/mysql.ibd/ mount point: /mnt/mysql/data/
[948170 20210120 14:30:23.889065Z][WARN][lib/dir_handle.cc:406] directory not exist: /mnt/mysql/data/mysql.ibd/
[948170 20210120 14:30:23.889073Z][INFO][lib/super_block.cc:235] check target path: /mnt/mysql/data/mysql.ibd mount point: /mnt/mysql/data/
[948170 20210120 14:30:23.889076Z][INFO][lib/file_handle.cc:135] transformPath dirname: /mnt/mysql/data/
[948170 20210120 14:30:23.889080Z][INFO][lib/file_handle.cc:136] transformPath filename: mysql.ibd
[948170 20210120 14:30:23.889085Z][INFO][lib/file.cc:214] mysql.ibd remove file block cut: 0
[948170 20210120 14:30:23.889091Z][INFO][lib/block_handle.cc:117] current block pool size: 31938
[948170 20210120 14:30:23.889097Z][INFO][lib/block_handle.cc:120] put block id: 8874 to free pool done
[948170 20210120 14:30:23.889102Z][INFO][lib/block_handle.cc:120] put block id: 27466 to free pool done
[948170 20210120 14:30:23.889107Z][INFO][lib/file_block.cc:8] clear file block index: 20 fh: 20
[948170 20210120 14:30:23.889128Z][INFO][lib/file_block.cc:29] write file block meta index: 20 crc:3285807419
[948170 20210120 14:30:23.889246Z][INFO][lib/file.cc:44] clear file name: mysql.ibd fh: 20
[948170 20210120 14:30:23.889254Z][INFO][lib/file.cc:173] release file name: mysql.ibd fh: 20 seq_no: 0
[948170 20210120 14:30:23.889261Z][INFO][lib/file.cc:29] write file meta, name: mysql.ibd fh: 20 align_index: 16 crc: 10247409133. 参考文章
c. use文件系统分析（一）
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