git: 11cfede1e62a - stable/13 - accounting: explicitly mark the exiting thread as doing accounting

[Konstantin Belousov]

The branch stable/13 has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=11cfede1e62afa1ff00cf97107bc48ebe1561ecb

commit 11cfede1e62afa1ff00cf97107bc48ebe1561ecb
Author:     Konstantin Belousov <kib at FreeBSD.org>
AuthorDate: 2021-05-13 23:48:58 +0000
Commit:     Konstantin Belousov <kib at FreeBSD.org>
CommitDate: 2021-06-13 01:22:33 +0000

    accounting: explicitly mark the exiting thread as doing accounting
    
    (cherry picked from commit 9bb84c23e762e7d1b6154ef4afdcc80662692e76)
---
 sys/kern/kern_acct.c | 26 +++++---------------------
 sys/kern/vfs_vnops.c |  3 ++-
 sys/sys/proc.h       |  1 +
 3 files changed, 8 insertions(+), 22 deletions(-)

diff --git a/sys/kern/kern_acct.c b/sys/kern/kern_acct.c
index 675113c6b2ba..4c1efada10da 100644
--- a/sys/kern/kern_acct.c
+++ b/sys/kern/kern_acct.c
@@ -141,7 +141,6 @@ static int		 acct_configured;
 static int		 acct_suspended;
 static struct vnode	*acct_vp;
 static struct ucred	*acct_cred;
-static struct plimit	*acct_limit;
 static int		 acct_flags;
 static struct sx	 acct_sx;
 
@@ -206,7 +205,7 @@ int
 sys_acct(struct thread *td, struct acct_args *uap)
 {
 	struct nameidata nd;
-	int error, flags, i, replacing;
+	int error, flags, replacing;
 
 	error = priv_check(td, PRIV_ACCT);
 	if (error)
@@ -276,15 +275,6 @@ sys_acct(struct thread *td, struct acct_args *uap)
 		return (error);
 	}
 
-	/*
-	 * Create our own plimit object without limits. It will be assigned
-	 * to exiting processes.
-	 */
-	acct_limit = lim_alloc();
-	for (i = 0; i < RLIM_NLIMITS; i++)
-		acct_limit->pl_rlimit[i].rlim_cur =
-		    acct_limit->pl_rlimit[i].rlim_max = RLIM_INFINITY;
-
 	/*
 	 * Save the new accounting file vnode, and schedule the new
 	 * free space watcher.
@@ -328,7 +318,6 @@ acct_disable(struct thread *td, int logging)
 	sx_assert(&acct_sx, SX_XLOCKED);
 	error = vn_close(acct_vp, acct_flags, acct_cred, td);
 	crfree(acct_cred);
-	lim_free(acct_limit);
 	acct_configured = 0;
 	acct_vp = NULL;
 	acct_cred = NULL;
@@ -349,7 +338,6 @@ acct_process(struct thread *td)
 {
 	struct acctv3 acct;
 	struct timeval ut, st, tmp;
-	struct plimit *oldlim;
 	struct proc *p;
 	struct rusage ru;
 	int t, ret;
@@ -374,6 +362,7 @@ acct_process(struct thread *td)
 	}
 
 	p = td->td_proc;
+	td->td_pflags2 |= TDP2_ACCT;
 
 	/*
 	 * Get process accounting information.
@@ -426,20 +415,14 @@ acct_process(struct thread *td)
 	/* (8) The boolean flags that tell how the process terminated, etc. */
 	acct.ac_flagx = p->p_acflag;
 
+	PROC_UNLOCK(p);
+
 	/* Setup ancillary structure fields. */
 	acct.ac_flagx |= ANVER;
 	acct.ac_zero = 0;
 	acct.ac_version = 3;
 	acct.ac_len = acct.ac_len2 = sizeof(acct);
 
-	/*
-	 * Eliminate rlimits (file size limit in particular).
-	 */
-	oldlim = p->p_limit;
-	p->p_limit = lim_hold(acct_limit);
-	PROC_UNLOCK(p);
-	lim_free(oldlim);
-
 	/*
 	 * Write the accounting information to the file.
 	 */
@@ -447,6 +430,7 @@ acct_process(struct thread *td)
 	    (off_t)0, UIO_SYSSPACE, IO_APPEND|IO_UNIT, acct_cred, NOCRED,
 	    NULL, td);
 	sx_sunlock(&acct_sx);
+	td->td_pflags2 &= ~TDP2_ACCT;
 	return (ret);
 }
 
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index 4ce4678f292f..8be30df40dc5 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -2361,7 +2361,8 @@ vn_rlimit_fsize(const struct vnode *vp, const struct uio *uio,
     struct thread *td)
 {
 
-	if (vp->v_type != VREG || td == NULL)
+	if (vp->v_type != VREG || td == NULL ||
+	    (td->td_pflags2 & TDP2_ACCT) != 0)
 		return (0);
 	if ((uoff_t)uio->uio_offset + uio->uio_resid >
 	    lim_cur(td, RLIMIT_FSIZE)) {
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index b0fc13a449cb..b47af58c34be 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -527,6 +527,7 @@ do {									\
 
 #define	TDP2_SBPAGES	0x00000001 /* Owns sbusy on some pages */
 #define	TDP2_COMPAT32RB	0x00000002 /* compat32 ABI for robust lists */
+#define	TDP2_ACCT	0x00000004 /* Doing accounting */
 
 /*
  * Reasons that the current thread can not be run yet.