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| author |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-02 16:59:15 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-05 13:02:34 +0200 |
| commit | dec9b2f1e0455a151a7293c367da22ab973f713e (patch) | |
| tree | 7ecf28aed34bca97422e7db5b22a41b175cc797f | |
| parent | driver core: fix driver_set_override() issue with empty strings (diff) | |
| download | linux-dev-dec9b2f1e0455a151a7293c367da22ab973f713e.tar.xz linux-dev-dec9b2f1e0455a151a7293c367da22ab973f713e.zip | |
debugfs: add debugfs_lookup_and_remove()
There is a very common pattern of using
debugfs_remove(debufs_lookup(..)) which results in a dentry leak of the
dentry that was looked up. Instead of having to open-code the correct
pattern of calling dput() on the dentry, create
debugfs_lookup_and_remove() to handle this pattern automatically and
properly without any memory leaks.
Cc: stable <stable@kernel.org>
Reported-by: Kuyo Chang <kuyo.chang@mediatek.com>
Tested-by: Kuyo Chang <kuyo.chang@mediatek.com>
Link: https://lore.kernel.org/r/YxIaQ8cSinDR881k@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to '')
| -rw-r--r-- | fs/debugfs/inode.c | 22 | ||||
| -rw-r--r-- | include/linux/debugfs.h | 6 |
2 files changed, 28 insertions, 0 deletions
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 3dcf0b8b4e93..232cfdf095ae 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -745,6 +745,28 @@ void debugfs_remove(struct dentry *dentry) EXPORT_SYMBOL_GPL(debugfs_remove); /** + * debugfs_lookup_and_remove - lookup a directory or file and recursively remove it + * @name: a pointer to a string containing the name of the item to look up. + * @parent: a pointer to the parent dentry of the item. + * + * This is the equlivant of doing something like + * debugfs_remove(debugfs_lookup(..)) but with the proper reference counting + * handled for the directory being looked up. + */ +void debugfs_lookup_and_remove(const char *name, struct dentry *parent) +{ + struct dentry *dentry; + + dentry = debugfs_lookup(name, parent); + if (!dentry) + return; + + debugfs_remove(dentry); + dput(dentry); +} +EXPORT_SYMBOL_GPL(debugfs_lookup_and_remove); + +/** * debugfs_rename - rename a file/directory in the debugfs filesystem * @old_dir: a pointer to the parent dentry for the renamed object. This * should be a directory dentry. diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index c869f1e73d75..f60674692d36 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -91,6 +91,8 @@ struct dentry *debugfs_create_automount(const char *name, void debugfs_remove(struct dentry *dentry); #define debugfs_remove_recursive debugfs_remove +void debugfs_lookup_and_remove(const char *name, struct dentry *parent); + const struct file_operations *debugfs_real_fops(const struct file *filp); int debugfs_file_get(struct dentry *dentry); @@ -225,6 +227,10 @@ static inline void debugfs_remove(struct dentry *dentry) static inline void debugfs_remove_recursive(struct dentry *dentry) { } +static inline void debugfs_lookup_and_remove(const char *name, + struct dentry *parent) +{ } + const struct file_operations *debugfs_real_fops(const struct file *filp); static inline int debugfs_file_get(struct dentry *dentry) |