coda: avoid lockdep warning in coda_readdir

Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/coda/dir.c b/fs/coda/dir.c
index 01f55f4..47ac9e2 100644 (file)
--- a/fs/coda/dir.c
+++ b/fs/coda/dir.c
@@ -43,15 +43,15 @@ static int coda_rename(struct inode *old_inode, struct dentry *old_dentry,
                        struct inode *new_inode, struct dentry *new_dentry);
 
 /* dir file-ops */
-static int coda_readdir(struct file *file, void *dirent, filldir_t filldir);
+static int coda_readdir(struct file *file, void *buf, filldir_t filldir);
 
 /* dentry ops */
 static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd);
 static int coda_dentry_delete(struct dentry *);
 
 /* support routines */
-static int coda_venus_readdir(struct file *filp, filldir_t filldir,
-                             void *dirent, struct dentry *dir);
+static int coda_venus_readdir(struct file *coda_file, void *buf,
+                             filldir_t filldir);
 
 /* same as fs/bad_inode.c */
 static int coda_return_EIO(void)
@@ -448,12 +448,10 @@ static int coda_rename(struct inode *old_dir, struct dentry *old_dentry,
 
 
 /* file operations for directories */
-int coda_readdir(struct file *coda_file, void *dirent, filldir_t filldir)
+int coda_readdir(struct file *coda_file, void *buf, filldir_t filldir)
 {
-       struct dentry *coda_dentry = coda_file->f_path.dentry;
        struct coda_file_info *cfi;
        struct file *host_file;
-       struct inode *host_inode;
        int ret;
 
        cfi = CODA_FTOC(coda_file);
@@ -462,30 +460,31 @@ int coda_readdir(struct file *coda_file, void *dirent, filldir_t filldir)
 
        coda_vfs_stat.readdir++;
 
-       host_inode = host_file->f_path.dentry->d_inode;
-       mutex_lock(&host_inode->i_mutex);
-       host_file->f_pos = coda_file->f_pos;
-
-       if (!host_file->f_op->readdir) {
-               /* Venus: we must read Venus dirents from the file */
-               ret = coda_venus_readdir(host_file, filldir, dirent, coda_dentry);
-       } else {
-               /* potemkin case: we were handed a directory inode. */
-               /* Yuk, we can't call vfs_readdir because we are already
-                * holding the inode semaphore. */
-               ret = -ENOTDIR;
-               if (!host_file->f_op || !host_file->f_op->readdir)
-                       goto out;
+       if (!host_file->f_op)
+               return -ENOTDIR;
+
+       if (host_file->f_op->readdir)
+       {
+               /* potemkin case: we were handed a directory inode.
+                * We can't use vfs_readdir because we have to keep the file
+                * position in sync between the coda_file and the host_file.
+                * and as such we need grab the inode mutex. */
+               struct inode *host_inode = host_file->f_path.dentry->d_inode;
+
+               mutex_lock(&host_inode->i_mutex);
+               host_file->f_pos = coda_file->f_pos;
 
                ret = -ENOENT;
                if (!IS_DEADDIR(host_inode)) {
-                       ret = host_file->f_op->readdir(host_file, dirent, filldir);
+                       ret = host_file->f_op->readdir(host_file, buf, filldir);
                        file_accessed(host_file);
                }
+
+               coda_file->f_pos = host_file->f_pos;
+               mutex_unlock(&host_inode->i_mutex);
        }
-out:
-       coda_file->f_pos = host_file->f_pos;
-       mutex_unlock(&host_inode->i_mutex);
+       else /* Venus: we must read Venus dirents from a file */
+               ret = coda_venus_readdir(coda_file, buf, filldir);
 
        return ret;
 }
@@ -510,57 +509,68 @@ static inline unsigned int CDT2DT(unsigned char cdt)
 }
 
 /* support routines */
-static int coda_venus_readdir(struct file *filp, filldir_t filldir,
-                             void *dirent, struct dentry *dir)
+static int coda_venus_readdir(struct file *coda_file, void *buf,
+                             filldir_t filldir)
 {
        int result = 0; /* # of entries returned */
+       struct coda_file_info *cfi;
+       struct coda_inode_info *cii;
+       struct file *host_file;
+       struct dentry *de;
        struct venus_dirent *vdir;
        unsigned long vdir_size =
            (unsigned long)(&((struct venus_dirent *)0)->d_name);
        unsigned int type;
        struct qstr name;
        ino_t ino;
-       int ret, i;
+       int ret;
+
+       cfi = CODA_FTOC(coda_file);
+       BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
+       host_file = cfi->cfi_container;
+
+       de = coda_file->f_path.dentry;
+       cii = ITOC(de->d_inode);
 
        vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
        if (!vdir) return -ENOMEM;
 
-       i = filp->f_pos;
-       switch(i) {
+       switch (coda_file->f_pos) {
        case 0:
-               ret = filldir(dirent, ".", 1, 0, dir->d_inode->i_ino, DT_DIR);
+               ret = filldir(buf, ".", 1, 0, de->d_inode->i_ino, DT_DIR);
                if (ret < 0) break;
                result++;
-               filp->f_pos++;
+               coda_file->f_pos++;
                /* fallthrough */
        case 1:
-               ret = filldir(dirent, "..", 2, 1, dir->d_parent->d_inode->i_ino, DT_DIR);
+               ret = filldir(buf, "..", 2, 1, de->d_parent->d_inode->i_ino, DT_DIR);
                if (ret < 0) break;
                result++;
-               filp->f_pos++;
+               coda_file->f_pos++;
                /* fallthrough */
        default:
        while (1) {
                /* read entries from the directory file */
-               ret = kernel_read(filp, filp->f_pos - 2, (char *)vdir,
+               ret = kernel_read(host_file, coda_file->f_pos - 2, (char *)vdir,
                                  sizeof(*vdir));
                if (ret < 0) {
-                       printk("coda_venus_readdir: read dir failed %d\n", ret);
+                       printk(KERN_ERR "coda readdir: read dir %s failed %d\n",
+                              coda_f2s(&cii->c_fid), ret);
                        break;
                }
                if (ret == 0) break; /* end of directory file reached */
 
                /* catch truncated reads */
                if (ret < vdir_size || ret < vdir_size + vdir->d_namlen) {
-                       printk("coda_venus_readdir: short read: %ld\n",
-                              filp->f_path.dentry->d_inode->i_ino);
+                       printk(KERN_ERR "coda readdir: short read on %s\n",
+                              coda_f2s(&cii->c_fid));
                        ret = -EBADF;
                        break;
                }
                /* validate whether the directory file actually makes sense */
                if (vdir->d_reclen < vdir_size + vdir->d_namlen) {
-                       printk("coda_venus_readdir: Invalid dir: %ld\n",
-                              filp->f_path.dentry->d_inode->i_ino);
+                       printk(KERN_ERR "coda readdir: invalid dir %s\n",
+                              coda_f2s(&cii->c_fid));
                        ret = -EBADF;
                        break;
                }
@@ -579,21 +589,21 @@ static int coda_venus_readdir(struct file *filp, filldir_t filldir,
                         * userspace doesn't have to worry about breaking
                         * getcwd by having mismatched inode numbers for
                         * internal volume mountpoints. */
-                       ino = find_inode_number(dir, &name);
+                       ino = find_inode_number(de, &name);
                        if (!ino) ino = vdir->d_fileno;
 
                        type = CDT2DT(vdir->d_type);
-                       ret = filldir(dirent, name.name, name.len, filp->f_pos,
-                                     ino, type); 
+                       ret = filldir(buf, name.name, name.len,
+                                     coda_file->f_pos, ino, type);
                        /* failure means no space for filling in this round */
                        if (ret < 0) break;
                        result++;
                }
                /* we'll always have progress because d_reclen is unsigned and
                 * we've already established it is non-zero. */
-               filp->f_pos += vdir->d_reclen;
+               coda_file->f_pos += vdir->d_reclen;
+       }
        }
-       } 
        kfree(vdir);
        return result ? result : ret;
 }