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Commit 06a35985 authored by Ian Kent's avatar Ian Kent Committed by Linus Torvalds
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autofs4: reorganize expire pending wait function calls 



This patch re-orgnirzes the checking for and waiting on active expires and
elininates redundant checks.

Signed-off-by: default avatarIan Kent <raven@themaw.net>
Cc: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ec6e8c7d

fs/autofs4/autofs_i.h

+1 −0
Original line number Diff line number Diff line
@@ -163,6 +163,7 @@ void autofs4_free_ino(struct autofs_info *); 


/* Expiration */

int is_autofs4_dentry(struct dentry *);

int autofs4_expire_wait(struct dentry *dentry);

int autofs4_expire_run(struct super_block *, struct vfsmount *,

			struct autofs_sb_info *,

			struct autofs_packet_expire __user *);

fs/autofs4/expire.c

+29 −0
Original line number Diff line number Diff line
@@ -402,6 +402,35 @@ static struct dentry *autofs4_expire_indirect(struct super_block *sb, 
	return expired;

}



int autofs4_expire_wait(struct dentry *dentry)

{

	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);

	struct autofs_info *ino = autofs4_dentry_ino(dentry);

	int status;



	/* Block on any pending expire */

	spin_lock(&sbi->fs_lock);

	if (ino->flags & AUTOFS_INF_EXPIRING) {

		spin_unlock(&sbi->fs_lock);



		DPRINTK("waiting for expire %p name=%.*s",

			 dentry, dentry->d_name.len, dentry->d_name.name);



		status = autofs4_wait(sbi, dentry, NFY_NONE);

		wait_for_completion(&ino->expire_complete);



		DPRINTK("expire done status=%d", status);



		if (d_unhashed(dentry))

			return -EAGAIN;



		return status;

	}

	spin_unlock(&sbi->fs_lock);



	return 0;

}



/* Perform an expiry operation */

int autofs4_expire_run(struct super_block *sb,

		      struct vfsmount *mnt,

fs/autofs4/root.c

+10 −65
Original line number Diff line number Diff line
@@ -130,34 +130,6 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags) 
	struct autofs_info *ino = autofs4_dentry_ino(dentry);

	int status;



	/* Block on any pending expiry here; invalidate the dentry

           when expiration is done to trigger mount request with a new

           dentry */

	spin_lock(&sbi->fs_lock);

	if (ino->flags & AUTOFS_INF_EXPIRING) {

		spin_unlock(&sbi->fs_lock);



		DPRINTK("waiting for expire %p name=%.*s",

			 dentry, dentry->d_name.len, dentry->d_name.name);



		status = autofs4_wait(sbi, dentry, NFY_NONE);

		wait_for_completion(&ino->expire_complete);



		DPRINTK("expire done status=%d", status);



		/*

		 * If the directory still exists the mount request must

		 * continue otherwise it can't be followed at the right

		 * time during the walk.

		 */

		status = d_invalidate(dentry);

		if (status != -EBUSY)

			return -EAGAIN;



		goto cont;

	}

	spin_unlock(&sbi->fs_lock);

cont:

	DPRINTK("dentry=%p %.*s ino=%p",

		 dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
@@ -248,22 +220,8 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd) 
	}



	/* If an expire request is pending everyone must wait. */

	spin_lock(&sbi->fs_lock);

	if (ino->flags & AUTOFS_INF_EXPIRING) {

		spin_unlock(&sbi->fs_lock);



		DPRINTK("waiting for active request %p name=%.*s",

			dentry, dentry->d_name.len, dentry->d_name.name);

	autofs4_expire_wait(dentry);



		status = autofs4_wait(sbi, dentry, NFY_NONE);

		wait_for_completion(&ino->expire_complete);



		DPRINTK("request done status=%d", status);



		goto cont;

	}

	spin_unlock(&sbi->fs_lock);

cont:

	/* We trigger a mount for almost all flags */

	lookup_type = nd->flags & (TRIGGER_FLAGS | TRIGGER_INTENTS);

	if (!(lookup_type || dentry->d_flags & DCACHE_AUTOFS_PENDING))
@@ -331,6 +289,14 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) 
		if (oz_mode)

			return 1;



		/*

		 * If the directory has gone away due to an expire

		 * we have been called as ->d_revalidate() and so

		 * we need to return false and proceed to ->lookup().

		 */

		if (autofs4_expire_wait(dentry) == -EAGAIN)

			return 0;



		/*

		 * A zero status is success otherwise we have a

		 * negative error code.
@@ -339,15 +305,6 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd) 
		if (status == 0)

			return 1;



		/*

		 * A status of EAGAIN here means that the dentry has gone

		 * away while waiting for an expire to complete. If we are

		 * racing with expire lookup will wait for it so this must

		 * be a revalidate and we need to send it to lookup.

		 */

		if (status == -EAGAIN)

			return 0;



		return status;

	}

	spin_unlock(&sbi->fs_lock);
@@ -557,19 +514,7 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s 
		 * so it must have been successful, so just wait for it.

		 */

		ino = autofs4_dentry_ino(expiring);

		spin_lock(&sbi->fs_lock);

		if (ino->flags & AUTOFS_INF_EXPIRING) {

			spin_unlock(&sbi->fs_lock);

			DPRINTK("wait for incomplete expire %p name=%.*s",

				expiring, expiring->d_name.len,

				expiring->d_name.name);

			autofs4_wait(sbi, expiring, NFY_NONE);

			wait_for_completion(&ino->expire_complete);

			DPRINTK("request completed");

			goto cont;

		}

		spin_unlock(&sbi->fs_lock);

cont:

		autofs4_expire_wait(expiring);

		spin_lock(&sbi->lookup_lock);

		if (!list_empty(&ino->expiring))

			list_del_init(&ino->expiring);