System-Calls

getdents 在 2 個系統上返回不同結果的原因可能是什麼？

  • April 19, 2021

我有一個奇怪的情況，在一台伺服器上我得到以下結果：

vagrant@shopping:/vagrant/deployer-example$ uname -a
Linux shopping 4.19.0-0.bpo.9-amd64 #1 SMP Debian 4.19.118-2+deb10u1~bpo9+1 (2020-06-09) x86_64 GNU/Linux


vagrant@shopping:/vagrant/deployer-example$ bin/php --version
PHP 8.0.3 (cli) (built: Mar  5 2021 08:36:11) ( NTS )
Copyright (c) The PHP Group
Zend Engine v4.0.3, Copyright (c) Zend Technologies
   with Zend OPcache v8.0.3, Copyright (c), by Zend Technologies
vagrant@shopping:/vagrant/deployer-example$ sudo ldd --version
ldd (Debian GLIBC 2.24-11+deb9u4) 2.24
Copyright (C) 2016 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Written by Roland McGrath and Ulrich Drepper.
vagrant@shopping:/vagrant/deployer-example$ php -r 'var_dump(glob("/vagrant/deployer-example/config/{routes}/*.yaml", GLOB_BRACE));'
array(4) {
 [0]=>
 string(56) "/vagrant/deployer-example/config/routes/annotations.yaml"
 [1]=>
 string(55) "/vagrant/deployer-example/config/routes/easy_admin.yaml"
 [2]=>
 string(52) "/vagrant/deployer-example/config/routes/monitor.yaml"
 [3]=>
 string(59) "/vagrant/deployer-example/config/routes/nelmio_api_doc.yaml"
}
vagrant@shopping:/vagrant/deployer-example$ php -r 'var_dump(glob("/vagrant/deployer-example/config/{routes}/*.yaml/", GLOB_BRACE));'
array(4) {
 [0]=>
 string(56) "/vagrant/deployer-example/config/routes/annotations.yaml"
 [1]=>
 string(55) "/vagrant/deployer-example/config/routes/easy_admin.yaml"
 [2]=>
 string(52) "/vagrant/deployer-example/config/routes/monitor.yaml"
 [3]=>
 string(59) "/vagrant/deployer-example/config/routes/nelmio_api_doc.yaml"
}

但是在第二個系統上

deployer-example@s2-stg-s01:~/deployer/current$ uname -a
Linux s2-stg-s01 4.19.0-0.bpo.9-amd64 #1 SMP Debian 4.19.118-2+deb10u1~bpo9+1 (2020-06-09) x86_64 GNU/Linux
deployer-example@s2-stg-s01:~/deployer/current$ bin/php --version
PHP 8.0.3 (cli) (built: Mar  5 2021 08:36:11) ( NTS )
Copyright (c) The PHP Group
Zend Engine v4.0.3, Copyright (c) Zend Technologies
   with Zend OPcache v8.0.3, Copyright (c), by Zend Technologies
deployer-example@s2-stg-s01:~/deployer/current$ ldd --version
ldd (Debian GLIBC 2.24-11+deb9u4) 2.24
Copyright © 2016 Free Software Foundation, Inc.
Dies ist freie Software; in den Quellen befinden sich die Lizenzbedingungen.
Es gibt KEINERLEI Garantie; nicht einmal für die TAUGLICHKEIT oder
VERWENDBARKEIT FÜR EINEN ANGEGEBENEN ZWECK.
Implementiert von Roland McGrath und Ulrich Drepper.
deployer-example@s2-stg-s01:~/deployer/current$ php -r 'var_dump(glob("/home/deployer-example/deployer/releases/437/config/{routes}/*.yaml", GLOB_BRACE));'
array(4) {
 [0]=>
 string(75) "/home/deployer-example/deployer/releases/437/config/routes/annotations.yaml"
 [1]=>
 string(74) "/home/deployer-example/deployer/releases/437/config/routes/easy_admin.yaml"
 [2]=>
 string(71) "/home/deployer-example/deployer/releases/437/config/routes/monitor.yaml"
 [3]=>
 string(78) "/home/deployer-example/deployer/releases/437/config/routes/nelmio_api_doc.yaml"
}
deployer-example@s2-stg-s01:~/deployer/current$ php -r 'var_dump(glob("/home/deployer-example/deployer/releases/437/config/{routes}/*.yaml/", GLOB_BRACE));'
array(0) {
}

我正在用 strace 調試它，發現對於第一個系統它報告：

open("/vagrant/deployer-example/config/routes", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 3
fstat(3, {st_dev=makedev(0, 44), st_ino=86530891, st_mode=S_IFDIR|0755, st_nlink=1, st_uid=1000, st_gid=1000, st_blksize=4096, st_blocks=8, st_size=224, st_atime=2021-03-12T15:24:14+0000, st_mtime=2021-03-12T15:19:23+0000, st_ctime=2021-03-12T15:19:23+0000}) = 0
brk(0x562b5bb63000)                     = 0x562b5bb63000
getdents(3, [{d_ino=1031795, d_off=1, d_reclen=24, d_name=".", d_type=DT_UNKNOWN}, {d_ino=1031796, d_off=2, d_reclen=24, d_name="..", d_type=DT_UNKNOWN}, {d_ino=1031797, d_off=3, d_reclen=40, d_name="annotations.yaml", d_type=DT_UNKNOWN}, {d_ino=1031798, d_off=4, d_reclen=24, d_name="dev", d_type=DT_UNKNOWN}, {d_ino=1031799, d_off=5, d_reclen=40, d_name="easy_admin.yaml", d_type=DT_UNKNOWN}, {d_ino=1031800, d_off=6, d_reclen=32, d_name="monitor.yaml", d_type=DT_UNKNOWN}, {d_ino=1031801, d_off=7, d_reclen=40, d_name="nelmio_api_doc.yaml", d_type=DT_UNKNOWN}], 32768) = 224
newfstatat(3, "annotations.yaml", {st_dev=makedev(0, 44), st_ino=87279600, st_mode=S_IFREG|0644, st_nlink=1, st_uid=1000, st_gid=1000, st_blksize=4096, st_blocks=8, st_size=135, st_atime=2021-03-12T15:19:24+0000, st_mtime=2021-03-12T15:19:23+0000, st_ctime=2021-03-12T15:19:23+0000}, 0) = 0
newfstatat(3, "easy_admin.yaml", {st_dev=makedev(0, 44), st_ino=87279603, st_mode=S_IFREG|0644, st_nlink=1, st_uid=1000, st_gid=1000, st_blksize=4096, st_blocks=8, st_size=127, st_atime=2021-03-05T16:00:41+0000, st_mtime=2021-03-05T16:00:41+0000, st_ctime=2021-03-05T16:00:41+0000}, 0) = 0
newfstatat(3, "monitor.yaml", {st_dev=makedev(0, 44), st_ino=87279604, st_mode=S_IFREG|0644, st_nlink=1, st_uid=1000, st_gid=1000, st_blksize=4096, st_blocks=8, st_size=137, st_atime=2021-03-05T16:00:41+0000, st_mtime=2021-03-05T16:00:41+0000, st_ctime=2021-03-05T16:00:41+0000}, 0) = 0
newfstatat(3, "nelmio_api_doc.yaml", {st_dev=makedev(0, 44), st_ino=87279605, st_mode=S_IFREG|0644, st_nlink=1, st_uid=1000, st_gid=1000, st_blksize=4096, st_blocks=8, st_size=367, st_atime=2021-03-05T16:00:41+0000, st_mtime=2021-03-05T16:00:41+0000, st_ctime=2021-03-05T16:00:41+0000}, 0) = 0
getdents(3, [], 32768)                  = 0
close(3)                                = 0

但對於第二個

open("/home/deployer-example/deployer/releases/437/config/routes", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
fstat(5, {st_dev=makedev(8, 17), st_ino=123601048, st_mode=S_IFDIR|0755, st_nlink=3, st_uid=1084, st_gid=1084, st_blksize=4096, st_blocks=8, st_size=4096, st_atime=2021-03-12T16:18:27+0100.512902323, st_mtime=2021-03-12T16:17:55+0100.984164843, st_ctime=2021-03-12T16:17:55+0100.984164843}) = 0
brk(0x557145c2a000)                     = 0x557145c2a000
getdents(5, [{d_ino=123601055, d_off=2396884471359371616, d_reclen=40, d_name="nelmio_api_doc.yaml", d_type=DT_REG}, {d_ino=123601053, d_off=2713394375622026215, d_reclen=32, d_name="monitor.yaml", d_type=DT_REG}, {d_ino=123601049, d_off=3087430337415459848, d_reclen=40, d_name="easy_admin.yaml", d_type=DT_REG}, {d_ino=123601050, d_off=7440370618885146051, d_reclen=24, d_name="dev", d_type=DT_DIR}, {d_ino=123600993, d_off=8681975314043990400, d_reclen=24, d_name="..", d_type=DT_DIR}, {d_ino=123601479, d_off=9220757504948275036, d_reclen=40, d_name="annotations.yaml", d_type=DT_REG}, {d_ino=123601048, d_off=9223372036854775807, d_reclen=24, d_name=".", d_type=DT_DIR}], 32768) = 224
getdents(5, [], 32768)                  = 0
close(5)                                = 0

兩個系統都在相同的 Debian 版本下執行，在 EXT4 文件系統下執行，並且配置了相同的 Ansible 腳本，因此也應該具有相同的核心包。

我怎樣才能把它縮小到罪魁禍首？有什麼可能的原因導致這兩個伺服器的行為不同？

由於 strace enabled ( ) 中的詳細模式可以看出-v，這些 getdents 呼叫d_type=DT_REG在第一個系統上返回，但在第二個系統上返回d_type=DT_UNKNOWN。這樣做的原因是，雖然在第一種情況下使用的文件系統是ext4，但在第二種情況下是prl_fs。prl_fs文件系統本身顯然不會返回 known d_type。

這會在 glibc 中的 glob() 函式中觸發邊緣情況。在https://sourceware.org/bugzilla/show_bug.cgi?id=25659報告了一個 glibc 錯誤問題

我還聯繫了 Parallels 支持，要求他們停止將 DT_UNKNOWN 作為 d_type 返回。從 Parallels 16.5.0-49183 開始，他們修復了這個問題:)

引用自：https://unix.stackexchange.com/questions/638955

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