Messages in this thread Patch in this message | | | From | Akinobu Mita <> | Subject | [PATCH 2/7] debugfs: add debugfs_create_int | Date | Sun, 3 Jul 2011 23:16:16 +0900 |
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Introduce debugfs_create_int() for creating a debugfs file that is used to read and write an int value.
It will be used by notifier error injection and there are two potential users of it (ceph/writeback_cngestion_kb and ocd/count on avr32)
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Greg Kroah-Hartman <gregkh@suse.de> --- fs/debugfs/file.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/debugfs.h | 9 +++++++ 2 files changed, 65 insertions(+), 0 deletions(-)
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 90f7657..05cb1c2 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -213,6 +213,62 @@ struct dentry *debugfs_create_u32(const char *name, mode_t mode, } EXPORT_SYMBOL_GPL(debugfs_create_u32); +static int debugfs_int_set(void *data, u64 val) +{ + *(int *)data = val; + return 0; +} + +static int debugfs_int_get(void *data, u64 *val) +{ + *val = *(int *)data; + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(fops_int, debugfs_int_get, debugfs_int_set, "%lld\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_int_ro, debugfs_int_get, NULL, "%lld\n"); +DEFINE_SIMPLE_ATTRIBUTE(fops_int_wo, NULL, debugfs_int_set, "%lld\n"); + +/** + * debugfs_create_int - create a debugfs file that is used to read and write an int value + * @name: a pointer to a string containing the name of the file to create. + * @mode: the permission that the file should have + * @parent: a pointer to the parent dentry for this file. This should be a + * directory dentry if set. If this parameter is %NULL, then the + * file will be created in the root of the debugfs filesystem. + * @value: a pointer to the variable that the file should read to and write + * from. + * + * This function creates a file in debugfs with the given name that + * contains the value of the variable @value. If the @mode variable is so + * set, it can be read from, and written to. + * + * This function will return a pointer to a dentry if it succeeds. This + * pointer must be passed to the debugfs_remove() function when the file is + * to be removed (no automatic cleanup happens if your module is unloaded, + * you are responsible here.) If an error occurs, %NULL will be returned. + * + * If debugfs is not enabled in the kernel, the value -%ENODEV will be + * returned. It is not wise to check for this value, but rather, check for + * %NULL or !%NULL instead as to eliminate the need for #ifdef in the calling + * code. + */ +struct dentry *debugfs_create_int(const char *name, mode_t mode, + struct dentry *parent, int *value) +{ + const struct file_operations *fops = &fops_int; + + /* if there are no write bits set, make read only */ + if (!(mode & S_IWUGO)) + fops = &fops_int_ro; + /* if there are no read bits set, make write only */ + if (!(mode & S_IRUGO)) + fops = &fops_u32_wo; + + return debugfs_create_file(name, mode, parent, value, fops); +} +EXPORT_SYMBOL_GPL(debugfs_create_int); + static int debugfs_u64_set(void *data, u64 val) { *(u64 *)data = val; diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index e7d9b20..6300792 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -55,6 +55,8 @@ struct dentry *debugfs_create_u16(const char *name, mode_t mode, struct dentry *parent, u16 *value); struct dentry *debugfs_create_u32(const char *name, mode_t mode, struct dentry *parent, u32 *value); +struct dentry *debugfs_create_int(const char *name, mode_t mode, + struct dentry *parent, int *value); struct dentry *debugfs_create_u64(const char *name, mode_t mode, struct dentry *parent, u64 *value); struct dentry *debugfs_create_x8(const char *name, mode_t mode, @@ -139,6 +141,13 @@ static inline struct dentry *debugfs_create_u32(const char *name, mode_t mode, return ERR_PTR(-ENODEV); } +static inline struct dentry *debugfs_create_int(const char *name, mode_t mode, + struct dentry *parent, + int *value); +{ + return ERR_PTR(-ENODEV); +} + static inline struct dentry *debugfs_create_u64(const char *name, mode_t mode, struct dentry *parent, u64 *value) -- 1.7.4.4
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