From 43e23b6c0b0151e308acbd6530bb80e2d2e53161 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 3 Jul 2019 09:16:53 +0200 Subject: [PATCH] debugfs: log errors when something goes wrong As it is not recommended that debugfs calls be checked, it was pointed out that major errors should still be logged somewhere so that developers and users have a chance to figure out what went wrong. To help with this, error logging has been added to the debugfs core so that it is not needed to be present in every individual file that calls debugfs. Reported-by: Mark Brown Reported-by: Takashi Iwai Reviewed-by: Mark Brown Reviewed-by: Takashi Iwai Reviewed-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20190703071653.2799-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman --- fs/debugfs/inode.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index acef14ad53db..c3638ac81cb6 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -2,8 +2,9 @@ /* * inode.c - part of debugfs, a tiny little debug file system * - * Copyright (C) 2004 Greg Kroah-Hartman + * Copyright (C) 2004,2019 Greg Kroah-Hartman * Copyright (C) 2004 IBM Inc. + * Copyright (C) 2019 Linux Foundation * * debugfs is for people to use instead of /proc or /sys. * See ./Documentation/core-api/kernel-api.rst for more details. @@ -292,8 +293,10 @@ static struct dentry *start_creating(const char *name, struct dentry *parent) error = simple_pin_fs(&debug_fs_type, &debugfs_mount, &debugfs_mount_count); - if (error) + if (error) { + pr_err("Unable to pin filesystem for file '%s'\n", name); return ERR_PTR(error); + } /* If the parent is not specified, we create it in the root. * We need the root dentry to do this, which is in the super @@ -307,6 +310,7 @@ static struct dentry *start_creating(const char *name, struct dentry *parent) dentry = lookup_one_len(name, parent, strlen(name)); if (!IS_ERR(dentry) && d_really_is_positive(dentry)) { dput(dentry); + pr_err("File '%s' already present!\n", name); dentry = ERR_PTR(-EEXIST); } @@ -349,8 +353,11 @@ static struct dentry *__debugfs_create_file(const char *name, umode_t mode, return dentry; inode = debugfs_get_inode(dentry->d_sb); - if (unlikely(!inode)) + if (unlikely(!inode)) { + pr_err("out of free dentries, can not create file '%s'\n", + name); return failed_creating(dentry); + } inode->i_mode = mode; inode->i_private = data; @@ -511,8 +518,11 @@ struct dentry *debugfs_create_dir(const char *name, struct dentry *parent) return dentry; inode = debugfs_get_inode(dentry->d_sb); - if (unlikely(!inode)) + if (unlikely(!inode)) { + pr_err("out of free dentries, can not create directory '%s'\n", + name); return failed_creating(dentry); + } inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO; inode->i_op = &simple_dir_inode_operations; @@ -550,8 +560,11 @@ struct dentry *debugfs_create_automount(const char *name, return dentry; inode = debugfs_get_inode(dentry->d_sb); - if (unlikely(!inode)) + if (unlikely(!inode)) { + pr_err("out of free dentries, can not create automount '%s'\n", + name); return failed_creating(dentry); + } make_empty_dir_inode(inode); inode->i_flags |= S_AUTOMOUNT; @@ -606,6 +619,8 @@ struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, inode = debugfs_get_inode(dentry->d_sb); if (unlikely(!inode)) { + pr_err("out of free dentries, can not create symlink '%s'\n", + name); kfree(link); return failed_creating(dentry); }