From 0b4e3d808fd00f692c43c759a43c1a43da983a7e Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Wed, 19 Feb 2020 14:44:11 +0100 Subject: [PATCH 1/4] test: Intercept open in vfs_error_inject Bug: https://bugzilla.samba.org/show_bug.cgi?id=14285 Signed-off-by: Volker Lendecke Reviewed-by: Jeremy Allison (cherry picked from commit 305204a241b74c599f4f6a064cac6608afd9c893) --- source3/modules/vfs_error_inject.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/source3/modules/vfs_error_inject.c b/source3/modules/vfs_error_inject.c index c8c3ea4701f..c7a99370b2a 100644 --- a/source3/modules/vfs_error_inject.c +++ b/source3/modules/vfs_error_inject.c @@ -29,6 +29,7 @@ struct unix_error_map { } unix_error_map_array[] = { { "ESTALE", ESTALE }, { "EBADF", EBADF }, + { "EINTR", EINTR }, }; static int find_unix_error_from_string(const char *err_str) @@ -106,9 +107,25 @@ static ssize_t vfs_error_inject_pwrite(vfs_handle_struct *handle, return SMB_VFS_NEXT_PWRITE(handle, fsp, data, n, offset); } +static int vfs_error_inject_open( + struct vfs_handle_struct *handle, + struct smb_filename *smb_fname, + files_struct *fsp, + int flags, + mode_t mode) +{ + int error = inject_unix_error("open", handle); + if (error != 0) { + errno = error; + return -1; + } + return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode); +} + static struct vfs_fn_pointers vfs_error_inject_fns = { .chdir_fn = vfs_error_inject_chdir, .pwrite_fn = vfs_error_inject_pwrite, + .open_fn = vfs_error_inject_open, }; static_decl_vfs; -- 2.20.1 From 8765dfc006b45c14d103d6a03be7effd18c0ce67 Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Wed, 19 Feb 2020 15:25:38 +0100 Subject: [PATCH 2/4] test: Show that smbd does not handle EINTR from open() correctly Bug: https://bugzilla.samba.org/show_bug.cgi?id=14285 Signed-off-by: Volker Lendecke Reviewed-by: Jeremy Allison (cherry picked from commit 7bbba73b30f06304e9a2ad48e853d9ec8171dd30) --- selftest/knownfail.d/open_eintr | 1 + source3/script/tests/test_open_eintr.sh | 66 +++++++++++++++++++++++++ source3/selftest/tests.py | 9 ++++ 3 files changed, 76 insertions(+) create mode 100644 selftest/knownfail.d/open_eintr create mode 100755 source3/script/tests/test_open_eintr.sh diff --git a/selftest/knownfail.d/open_eintr b/selftest/knownfail.d/open_eintr new file mode 100644 index 00000000000..e5b42ed6bcd --- /dev/null +++ b/selftest/knownfail.d/open_eintr @@ -0,0 +1 @@ +samba3.blackbox.open-eintr.*$simpleserver:local$ diff --git a/source3/script/tests/test_open_eintr.sh b/source3/script/tests/test_open_eintr.sh new file mode 100755 index 00000000000..d08f7fcfc23 --- /dev/null +++ b/source3/script/tests/test_open_eintr.sh @@ -0,0 +1,66 @@ +#!/bin/bash +# +# Test smbd handling when open returns EINTR +# +# Copyright (C) 2020 Volker Lendecke + +if [ $# -lt 5 ]; then + echo Usage: test_open_eintr.sh \ + --configfile=SERVERCONFFILE SMBCLIENT SMBCONTROL SERVER SHARE +exit 1 +fi + +CONF=$1; shift 1 +SMBCLIENT=$1; shift 1 +SMBCONTROL=$1; shift 1 +SERVER=$1; shift 1 +SHARE=$1; shift 1 + +error_inject_conf=$(dirname ${SERVERCONFFILE})/error_inject.conf +> ${error_inject_conf} + +incdir=$(dirname $0)/../../../testprogs/blackbox +. $incdir/subunit.sh + +failed=0 + +rm -f smbclient-stdin smbclient-stdout smbclient-stderr +mkfifo smbclient-stdin smbclient-stdout smbclient-stderr + +CLI_FORCE_INTERACTIVE=1; export CLI_FORCE_INTERACTIVE + +${SMBCLIENT} //${SERVER}/${SHARE} ${CONF} -U${USER}%${PASSWORD} \ + < smbclient-stdin > smbclient-stdout 2>smbclient-stderr & +CLIENT_PID=$! + +sleep 1 + +exec 100>smbclient-stdin 101 ${error_inject_conf} +${SMBCONTROL} ${CONF} 0 reload-config + +sleep 1 +> ${error_inject_conf} + +echo 'get badnames/blank.txt -' >&100 + +sleep 1 + +> ${error_inject_conf} +${SMBCONTROL} ${CONF} 0 reload-config + +head -n 1 <&102 | grep 'getting file' > /dev/null +GREP_RET=$? + +kill ${CLIENT_PID} +rm -f smbclient-stdin smbclient-stdout smbclient-stderr + +testit "Verify that we could get the file" \ + test $GREP_RET -eq 0 || failed=$(expr $failed + 1) + +testok $0 $failed diff --git a/source3/selftest/tests.py b/source3/selftest/tests.py index 67e9282459c..5c43e6e9458 100755 --- a/source3/selftest/tests.py +++ b/source3/selftest/tests.py @@ -751,6 +751,15 @@ plantestsuite("samba3.blackbox.sharesec", "simpleserver:local", [os.path.join(samba3srcdir, "script/tests/test_sharesec.sh"), configuration, os.path.join(bindir(), "sharesec"), "tmp"]) +plantestsuite("samba3.blackbox.open-eintr", "simpleserver:local", + [os.path.join(samba3srcdir, + "script/tests/test_open_eintr.sh"), + configuration, + os.path.join(bindir(), "smbclient"), + os.path.join(bindir(), "smbcontrol"), + '$SERVER_IP', + "error_inject"]) + plantestsuite("samba3.blackbox.net_tdb", "simpleserver:local", [os.path.join(samba3srcdir, "script/tests/test_net_tdb.sh"), smbclient3, '$SERVER', 'tmp', '$USERNAME', '$PASSWORD', -- 2.20.1 From b63179cf7bbfe734362eb7ff116c1b9dbccae8e1 Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Thu, 20 Feb 2020 10:25:16 +0100 Subject: [PATCH 3/4] lib: Map EINPROGRESS->NT_STATUS_MORE_PROCESSING_REQUIRED Bug: https://bugzilla.samba.org/show_bug.cgi?id=14285 Signed-off-by: Volker Lendecke Reviewed-by: Jeremy Allison (cherry picked from commit 4a943d842a51674425f0c4019f823ef0a9d09f49) --- source3/lib/errmap_unix.c | 1 + 1 file changed, 1 insertion(+) diff --git a/source3/lib/errmap_unix.c b/source3/lib/errmap_unix.c index 9eb30f7b814..20cc714ea9d 100644 --- a/source3/lib/errmap_unix.c +++ b/source3/lib/errmap_unix.c @@ -118,6 +118,7 @@ static const struct { #ifdef EOVERFLOW { EOVERFLOW, NT_STATUS_ALLOTTED_SPACE_EXCEEDED }, #endif + { EINPROGRESS, NT_STATUS_MORE_PROCESSING_REQUIRED }, }; /********************************************************************* -- 2.20.1 From d400fe687202e466995345df8d6a2acd363ea489 Mon Sep 17 00:00:00 2001 From: Volker Lendecke Date: Thu, 20 Feb 2020 14:13:35 +0100 Subject: [PATCH 4/4] smbd: Separate aio_pthread indicator from normal EINTR According to Posix and the Linux open(2) manpage, the open-syscall can return EINTR. If that happens, core smbd saw this as an indication that aio_pthread's open function was doing its job. With a real EINTR without aio_pthread this meant we ended up in a server_exit after 20 seconds, because there was nobody to do the retry. EINTR is mapped to NT_STATUS_RETRY. Handle this by just retrying after a second. Bug: https://bugzilla.samba.org/show_bug.cgi?id=14285 Signed-off-by: Volker Lendecke Reviewed-by: Jeremy Allison Autobuild-User(master): Jeremy Allison Autobuild-Date(master): Thu Feb 20 22:14:25 UTC 2020 on sn-devel-184 (cherry picked from commit aebe427b77b5315eb5d2b05b8c72824ca0389723) --- selftest/knownfail.d/open_eintr | 1 - source3/modules/vfs_aio_pthread.c | 2 +- source3/smbd/open.c | 38 ++++++++++++++++++++++--------- 3 files changed, 28 insertions(+), 13 deletions(-) delete mode 100644 selftest/knownfail.d/open_eintr diff --git a/selftest/knownfail.d/open_eintr b/selftest/knownfail.d/open_eintr deleted file mode 100644 index e5b42ed6bcd..00000000000 --- a/selftest/knownfail.d/open_eintr +++ /dev/null @@ -1 +0,0 @@ -samba3.blackbox.open-eintr.*$simpleserver:local$ diff --git a/source3/modules/vfs_aio_pthread.c b/source3/modules/vfs_aio_pthread.c index 577180b6b01..5febdd3af32 100644 --- a/source3/modules/vfs_aio_pthread.c +++ b/source3/modules/vfs_aio_pthread.c @@ -318,7 +318,7 @@ static int open_async(const files_struct *fsp, opd->fname)); /* Cause the calling code to reschedule us. */ - errno = EINTR; /* Maps to NT_STATUS_RETRY. */ + errno = EINPROGRESS; /* Maps to NT_STATUS_MORE_PROCESSING_REQUIRED. */ return -1; } diff --git a/source3/smbd/open.c b/source3/smbd/open.c index 5524f80af20..871cc72053f 100644 --- a/source3/smbd/open.c +++ b/source3/smbd/open.c @@ -2960,6 +2960,7 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn, SMB_STRUCT_STAT saved_stat = smb_fname->st; struct timespec old_write_time; struct file_id id; + bool setup_poll = false; if (conn->printer) { /* @@ -3290,8 +3291,14 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn, open_access_mask, &new_file_created); if (NT_STATUS_EQUAL(fsp_open, NT_STATUS_NETWORK_BUSY)) { - bool delay; - + if (file_existed && S_ISFIFO(fsp->fsp_name->st.st_ex_mode)) { + DEBUG(10, ("FIFO busy\n")); + return NT_STATUS_NETWORK_BUSY; + } + if (req == NULL) { + DEBUG(10, ("Internal open busy\n")); + return NT_STATUS_NETWORK_BUSY; + } /* * This handles the kernel oplock case: * @@ -3301,14 +3308,21 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn, * "Samba locking.tdb oplocks" are handled below after acquiring * the sharemode lock with get_share_mode_lock(). */ - if (file_existed && S_ISFIFO(fsp->fsp_name->st.st_ex_mode)) { - DEBUG(10, ("FIFO busy\n")); - return NT_STATUS_NETWORK_BUSY; - } - if (req == NULL) { - DEBUG(10, ("Internal open busy\n")); - return NT_STATUS_NETWORK_BUSY; - } + setup_poll = true; + } + + if (NT_STATUS_EQUAL(fsp_open, NT_STATUS_RETRY)) { + /* + * EINTR from the open(2) syscall. Just setup a retry + * in a bit. We can't use the sys_write() tight retry + * loop here, as we might have to actually deal with + * lease-break signals to avoid a deadlock. + */ + setup_poll = true; + } + + if (setup_poll) { + bool delay; /* * From here on we assume this is an oplock break triggered @@ -3359,7 +3373,9 @@ static NTSTATUS open_file_ntcreate(connection_struct *conn, } if (!NT_STATUS_IS_OK(fsp_open)) { - if (NT_STATUS_EQUAL(fsp_open, NT_STATUS_RETRY)) { + bool wait_for_aio = NT_STATUS_EQUAL( + fsp_open, NT_STATUS_MORE_PROCESSING_REQUIRED); + if (wait_for_aio) { schedule_async_open(request_time, req); } return fsp_open; -- 2.20.1