Attachment 882803 Details for Bug 1082586 – patch -- locks: add new i_last_lease_break field to struct inode

[patch] patch -- locks: add new i_last_lease_break field to struct inode

0001-locks-add-a-new-i_last_lease_break-field-to-struct-i.patch (text/plain), 3.21 KB, created by Jeff Layton on 2014-04-04 17:17:39 UTC

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Creator: Jeff Layton

Created: 2014-04-04 17:17:39 UTC

Size: 3.21 KB

patch

obsolete

>From 8324c9fd1a15160fd1f98aada97c4df22915915f Mon Sep 17 00:00:00 2001
>From: Jeff Layton <jlayton@redhat.com>
>Date: Fri, 4 Apr 2014 07:17:45 -0400
>Subject: [PATCH] locks: add a new i_last_lease_break field to struct inode
>
>...and use that as a guide as to whether a delegation should be
>granted.
>
>Signed-off-by: Jeff Layton <jlayton@redhat.com>
>---
> fs/inode.c         |  1 +
> fs/locks.c         | 40 +++++++++++++++++++++++++---------------
> include/linux/fs.h |  1 +
> 3 files changed, 27 insertions(+), 15 deletions(-)
>
>diff --git a/fs/inode.c b/fs/inode.c
>index 4bcdad3c9361..3588667985d7 100644
>--- a/fs/inode.c
>+++ b/fs/inode.c
>@@ -151,6 +151,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode)
> 	inode->i_cdev = NULL;
> 	inode->i_rdev = 0;
> 	inode->dirtied_when = 0;
>+	inode->i_last_lease_break = 0;
> 
> 	if (security_inode_alloc(inode))
> 		goto out;
>diff --git a/fs/locks.c b/fs/locks.c
>index 4d2099d0cb39..fa8e0c30c1ce 100644
>--- a/fs/locks.c
>+++ b/fs/locks.c
>@@ -1390,6 +1390,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
> 	}
> 
> restart:
>+	inode->i_last_lease_break = jiffies;
> 	break_time = flock->fl_break_time;
> 	if (break_time != 0) {
> 		break_time -= jiffies;
>@@ -1522,22 +1523,31 @@ static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp
> 	int error;
> 
> 	lease = *flp;
>-	/*
>-	 * In the delegation case we need mutual exclusion with
>-	 * a number of operations that take the i_mutex.  We trylock
>-	 * because delegations are an optional optimization, and if
>-	 * there's some chance of a conflict--we'd rather not
>-	 * bother, maybe that's a sign this just isn't a good file to
>-	 * hand out a delegation on.
>-	 */
>-	if (is_deleg && !mutex_trylock(&inode->i_mutex))
>-		return -EAGAIN;
>+	if (is_deleg) {
>+		/* Don't hand out a delegation if we recently broke one. */
>+		if (inode->i_last_lease_break &&
>+		    time_before(jiffies, inode->i_last_lease_break +
>+					2 * lease_break_time))
>+			return -EAGAIN;
>+
>+		/*
>+		 * In the delegation case we need mutual exclusion with
>+		 * a number of operations that take the i_mutex.  We trylock
>+		 * because delegations are an optional optimization, and if
>+		 * there's some chance of a conflict--we'd rather not
>+		 * bother, maybe that's a sign this just isn't a good file to
>+		 * hand out a delegation on.
>+		 */
>+		if (!mutex_trylock(&inode->i_mutex))
>+			return -EAGAIN;
>+
>+		if (arg == F_WRLCK) {
>+			/* Write delegations are not currently supported: */
>+			mutex_unlock(&inode->i_mutex);
>+			WARN_ON_ONCE(1);
>+			return -EINVAL;
>+		}
> 
>-	if (is_deleg && arg == F_WRLCK) {
>-		/* Write delegations are not currently supported: */
>-		mutex_unlock(&inode->i_mutex);
>-		WARN_ON_ONCE(1);
>-		return -EINVAL;
> 	}
> 
> 	error = check_conflicting_open(dentry, arg);
>diff --git a/include/linux/fs.h b/include/linux/fs.h
>index 4aa81e6ae067..ceff64083644 100644
>--- a/include/linux/fs.h
>+++ b/include/linux/fs.h
>@@ -588,6 +588,7 @@ struct inode {
> 	atomic_t		i_writecount;
> 	const struct file_operations	*i_fop;	/* former ->i_op->default_file_ops */
> 	struct file_lock	*i_flock;
>+	unsigned long		i_last_lease_break; /* jiffies at last lease break */
> 	struct address_space	i_data;
> #ifdef CONFIG_QUOTA
> 	struct dquot		*i_dquot[MAXQUOTAS];
>-- 
>1.9.0
>

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Attachments on bug 1082586: 880725 | 882803