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Diffstat (limited to 'fs/nfsd/vfs.c')
-rw-r--r--fs/nfsd/vfs.c34
1 files changed, 26 insertions, 8 deletions
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index ab93fcfef25..6c68ffd6b4b 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -116,10 +116,15 @@ nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
}
if ((exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
/* successfully crossed mount point */
- exp_put(exp);
- *expp = exp2;
+ /*
+ * This is subtle: dentry is *not* under mnt at this point.
+ * The only reason we are safe is that original mnt is pinned
+ * down by exp, so we should dput before putting exp.
+ */
dput(dentry);
*dpp = mounts;
+ exp_put(exp);
+ *expp = exp2;
} else {
exp_put(exp2);
dput(mounts);
@@ -1885,8 +1890,8 @@ static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen,
return 0;
}
-static int nfsd_buffered_readdir(struct file *file, filldir_t func,
- struct readdir_cd *cdp, loff_t *offsetp)
+static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func,
+ struct readdir_cd *cdp, loff_t *offsetp)
{
struct readdir_data buf;
struct buffered_dirent *de;
@@ -1896,11 +1901,12 @@ static int nfsd_buffered_readdir(struct file *file, filldir_t func,
buf.dirent = (void *)__get_free_page(GFP_KERNEL);
if (!buf.dirent)
- return -ENOMEM;
+ return nfserrno(-ENOMEM);
offset = *offsetp;
while (1) {
+ struct inode *dir_inode = file->f_path.dentry->d_inode;
unsigned int reclen;
cdp->err = nfserr_eof; /* will be cleared on successful read */
@@ -1919,26 +1925,38 @@ static int nfsd_buffered_readdir(struct file *file, filldir_t func,
if (!size)
break;
+ /*
+ * Various filldir functions may end up calling back into
+ * lookup_one_len() and the file system's ->lookup() method.
+ * These expect i_mutex to be held, as it would within readdir.
+ */
+ host_err = mutex_lock_killable(&dir_inode->i_mutex);
+ if (host_err)
+ break;
+
de = (struct buffered_dirent *)buf.dirent;
while (size > 0) {
offset = de->offset;
if (func(cdp, de->name, de->namlen, de->offset,
de->ino, de->d_type))
- goto done;
+ break;
if (cdp->err != nfs_ok)
- goto done;
+ break;
reclen = ALIGN(sizeof(*de) + de->namlen,
sizeof(u64));
size -= reclen;
de = (struct buffered_dirent *)((char *)de + reclen);
}
+ mutex_unlock(&dir_inode->i_mutex);
+ if (size > 0) /* We bailed out early */
+ break;
+
offset = vfs_llseek(file, 0, SEEK_CUR);
}
- done:
free_page((unsigned long)(buf.dirent));
if (host_err)