diff options
Diffstat (limited to 'fs/autofs4/root.c')
-rw-r--r-- | fs/autofs4/root.c | 40 |
1 files changed, 31 insertions, 9 deletions
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index a54a946..edf5b6b 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -146,17 +146,17 @@ static int autofs4_dir_open(struct inode *inode, struct file *file) if (d_mountpoint(dentry)) { struct file *fp = NULL; - struct vfsmount *fp_mnt = mntget(mnt); - struct dentry *fp_dentry = dget(dentry); + struct path fp_path = { .dentry = dentry, .mnt = mnt }; - if (!autofs4_follow_mount(&fp_mnt, &fp_dentry)) { - dput(fp_dentry); - mntput(fp_mnt); + path_get(&fp_path); + + if (!autofs4_follow_mount(&fp_path.mnt, &fp_path.dentry)) { + path_put(&fp_path); dcache_dir_close(inode, file); goto out; } - fp = dentry_open(fp_dentry, fp_mnt, file->f_flags); + fp = dentry_open(fp_path.dentry, fp_path.mnt, file->f_flags); status = PTR_ERR(fp); if (IS_ERR(fp)) { dcache_dir_close(inode, file); @@ -242,7 +242,8 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags) { struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb); struct autofs_info *ino = autofs4_dentry_ino(dentry); - int status = 0; + struct dentry *new; + int status; /* Block on any pending expiry here; invalidate the dentry when expiration is done to trigger mount request with a new @@ -318,7 +319,28 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags) spin_lock(&dentry->d_lock); dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; spin_unlock(&dentry->d_lock); - return status; + + /* + * The dentry that is passed in from lookup may not be the one + * we end up using, as mkdir can create a new one. If this + * happens, and another process tries the lookup at the same time, + * it will set the PENDING flag on this new dentry, but add itself + * to our waitq. Then, if after the lookup succeeds, the first + * process that requested the mount performs another lookup of the + * same directory, it will show up as still pending! So, we need + * to redo the lookup here and clear pending on that dentry. + */ + if (d_unhashed(dentry)) { + new = d_lookup(dentry->d_parent, &dentry->d_name); + if (new) { + spin_lock(&new->d_lock); + new->d_flags &= ~DCACHE_AUTOFS_PENDING; + spin_unlock(&new->d_lock); + dput(new); + } + } + + return 0; } /* For autofs direct mounts the follow link triggers the mount */ @@ -533,9 +555,9 @@ static struct dentry *autofs4_lookup_unhashed(struct autofs_sb_info *sbi, struct goto next; if (d_unhashed(dentry)) { - struct autofs_info *ino = autofs4_dentry_ino(dentry); struct inode *inode = dentry->d_inode; + ino = autofs4_dentry_ino(dentry); list_del_init(&ino->rehash); dget(dentry); /* |