From 06a3598552dc3b2b30eb18bd53bbac2a901489d7 Mon Sep 17 00:00:00 2001 From: Ian Kent Date: Wed, 23 Jul 2008 21:30:28 -0700 Subject: [PATCH] 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: Ian Kent Cc: Jeff Moyer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/autofs4/autofs_i.h | 1 + fs/autofs4/expire.c | 29 +++++++++++++++++ fs/autofs4/root.c | 75 ++++++------------------------------------- 3 files changed, 40 insertions(+), 65 deletions(-) diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h index 4b40cbc71e9..69a2f5c9231 100644 --- a/fs/autofs4/autofs_i.h +++ b/fs/autofs4/autofs_i.h @@ -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 *); diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c index 705b9f057fb..cdabb796ff0 100644 --- a/fs/autofs4/expire.c +++ b/fs/autofs4/expire.c @@ -402,6 +402,35 @@ found: 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, diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index e062ee5a3ed..ae22bde0bbd 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -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); - - status = autofs4_wait(sbi, dentry, NFY_NONE); - wait_for_completion(&ino->expire_complete); + autofs4_expire_wait(dentry); - 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); -- 2.41.1