From 43e23b6c0b0151e308acbd6530bb80e2d2e53161 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 3 Jul 2019 09:16:53 +0200 Subject: 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(-) (limited to 'fs/debugfs/inode.c') 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); } -- cgit v1.2.2 From d03ae4778b3b61fc329615c30972074ee3496b0a Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 3 Jul 2019 09:16:52 +0200 Subject: debugfs: provide pr_fmt() macro Use a common "debugfs: " prefix for all pr_* calls in a single place. Cc: Mark Brown Reviewed-by: Takashi Iwai Reviewed-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20190703071653.2799-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman --- fs/debugfs/inode.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'fs/debugfs/inode.c') diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index c3638ac81cb6..7f43c8acfcbf 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -10,6 +10,8 @@ * See ./Documentation/core-api/kernel-api.rst for more details. */ +#define pr_fmt(fmt) "debugfs: " fmt + #include #include #include @@ -286,7 +288,7 @@ static struct dentry *start_creating(const char *name, struct dentry *parent) struct dentry *dentry; int error; - pr_debug("debugfs: creating file '%s'\n",name); + pr_debug("creating file '%s'\n", name); if (IS_ERR(parent)) return parent; -- cgit v1.2.2 From c33d442328f556460b79aba6058adb37bb555389 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Sat, 6 Jul 2019 17:42:56 +0200 Subject: debugfs: make error message a bit more verbose When a file/directory is already present in debugfs, and it is attempted to be created again, be more specific about what file/directory is being created and where it is trying to be created to give a bit more help to developers to figure out the problem. Cc: Stephen Rothwell Cc: Rafael J. Wysocki Cc: Mark Brown Cc: Takashi Iwai Reviewed-by: Mark Brown Link: https://lore.kernel.org/r/20190706154256.GA2683@kroah.com Signed-off-by: Greg Kroah-Hartman --- fs/debugfs/inode.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'fs/debugfs/inode.c') diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 7f43c8acfcbf..5836312269e0 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -311,8 +311,13 @@ static struct dentry *start_creating(const char *name, struct dentry *parent) inode_lock(d_inode(parent)); dentry = lookup_one_len(name, parent, strlen(name)); if (!IS_ERR(dentry) && d_really_is_positive(dentry)) { + if (d_is_dir(dentry)) + pr_err("Directory '%s' with parent '%s' already present!\n", + name, parent->d_name.name); + else + pr_err("File '%s' in directory '%s' already present!\n", + name, parent->d_name.name); dput(dentry); - pr_err("File '%s' already present!\n", name); dentry = ERR_PTR(-EEXIST); } -- cgit v1.2.2