diff options
Diffstat (limited to 'include/linux/pstore.h')
| -rw-r--r-- | include/linux/pstore.h | 156 |
1 files changed, 131 insertions, 25 deletions
diff --git a/include/linux/pstore.h b/include/linux/pstore.h index 0da29cae009b..e2233f50f428 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h @@ -30,7 +30,9 @@ #include <linux/time.h> #include <linux/types.h> -/* types */ +struct module; + +/* pstore record types (see fs/pstore/inode.c for filename templates) */ enum pstore_type_id { PSTORE_TYPE_DMESG = 0, PSTORE_TYPE_MCE = 1, @@ -45,42 +47,146 @@ enum pstore_type_id { PSTORE_TYPE_UNKNOWN = 255 }; -struct module; +struct pstore_info; +/** + * struct pstore_record - details of a pstore record entry + * @psi: pstore backend driver information + * @type: pstore record type + * @id: per-type unique identifier for record + * @time: timestamp of the record + * @buf: pointer to record contents + * @size: size of @buf + * @ecc_notice_size: + * ECC information for @buf + * + * Valid for PSTORE_TYPE_DMESG @type: + * + * @count: Oops count since boot + * @reason: kdump reason for notification + * @part: position in a multipart record + * @compressed: whether the buffer is compressed + * + */ +struct pstore_record { + struct pstore_info *psi; + enum pstore_type_id type; + u64 id; + struct timespec time; + char *buf; + ssize_t size; + ssize_t ecc_notice_size; + int count; + enum kmsg_dump_reason reason; + unsigned int part; + bool compressed; +}; + +/** + * struct pstore_info - backend pstore driver structure + * + * @owner: module which is repsonsible for this backend driver + * @name: name of the backend driver + * + * @buf_lock: spinlock to serialize access to @buf + * @buf: preallocated crash dump buffer + * @bufsize: size of @buf available for crash dump writes + * + * @read_mutex: serializes @open, @read, @close, and @erase callbacks + * @flags: bitfield of frontends the backend can accept writes for + * @data: backend-private pointer passed back during callbacks + * + * Callbacks: + * + * @open: + * Notify backend that pstore is starting a full read of backend + * records. Followed by one or more @read calls, and a final @close. + * + * @psi: in: pointer to the struct pstore_info for the backend + * + * Returns 0 on success, and non-zero on error. + * + * @close: + * Notify backend that pstore has finished a full read of backend + * records. Always preceded by an @open call and one or more @read + * calls. + * + * @psi: in: pointer to the struct pstore_info for the backend + * + * Returns 0 on success, and non-zero on error. (Though pstore will + * ignore the error.) + * + * @read: + * Read next available backend record. Called after a successful + * @open. + * + * @record: + * pointer to record to populate. @buf should be allocated + * by the backend and filled. At least @type and @id should + * be populated, since these are used when creating pstorefs + * file names. + * + * Returns record size on success, zero when no more records are + * available, or negative on error. + * + * @write: + * A newly generated record needs to be written to backend storage. + * + * @record: + * pointer to record metadata. When @type is PSTORE_TYPE_DMESG, + * @buf will be pointing to the preallocated @psi.buf, since + * memory allocation may be broken during an Oops. Regardless, + * @buf must be proccesed or copied before returning. The + * backend is also expected to write @id with something that + 8 can help identify this record to a future @erase callback. + * + * Returns 0 on success, and non-zero on error. + * + * @write_user: + * Perform a frontend write to a backend record, using a specified + * buffer that is coming directly from userspace, instead of the + * @record @buf. + * + * @record: pointer to record metadata. + * @buf: pointer to userspace contents to write to backend + * + * Returns 0 on success, and non-zero on error. + * + * @erase: + * Delete a record from backend storage. Different backends + * identify records differently, so entire original record is + * passed back to assist in identification of what the backend + * should remove from storage. + * + * @record: pointer to record metadata. + * + * Returns 0 on success, and non-zero on error. + * + */ struct pstore_info { struct module *owner; char *name; - spinlock_t buf_lock; /* serialize access to 'buf' */ + + spinlock_t buf_lock; char *buf; size_t bufsize; - struct mutex read_mutex; /* serialize open/read/close */ + + struct mutex read_mutex; + int flags; + void *data; + int (*open)(struct pstore_info *psi); int (*close)(struct pstore_info *psi); - ssize_t (*read)(u64 *id, enum pstore_type_id *type, - int *count, struct timespec *time, char **buf, - bool *compressed, ssize_t *ecc_notice_size, - struct pstore_info *psi); - int (*write)(enum pstore_type_id type, - enum kmsg_dump_reason reason, u64 *id, - unsigned int part, int count, bool compressed, - size_t size, struct pstore_info *psi); - int (*write_buf)(enum pstore_type_id type, - enum kmsg_dump_reason reason, u64 *id, - unsigned int part, const char *buf, bool compressed, - size_t size, struct pstore_info *psi); - int (*write_buf_user)(enum pstore_type_id type, - enum kmsg_dump_reason reason, u64 *id, - unsigned int part, const char __user *buf, - bool compressed, size_t size, struct pstore_info *psi); - int (*erase)(enum pstore_type_id type, u64 id, - int count, struct timespec time, - struct pstore_info *psi); - void *data; + ssize_t (*read)(struct pstore_record *record); + int (*write)(struct pstore_record *record); + int (*write_user)(struct pstore_record *record, + const char __user *buf); + int (*erase)(struct pstore_record *record); }; +/* Supported frontends */ #define PSTORE_FLAGS_DMESG (1 << 0) -#define PSTORE_FLAGS_FRAGILE PSTORE_FLAGS_DMESG #define PSTORE_FLAGS_CONSOLE (1 << 1) #define PSTORE_FLAGS_FTRACE (1 << 2) #define PSTORE_FLAGS_PMSG (1 << 3) |