#define XLOG_RECOVERY_NEEDED 0x4 /* log was recovered */
#define XLOG_IO_ERROR 0x8 /* log hit an I/O error, and being
shutdown */
-typedef __uint32_t xlog_tid_t;
-
#ifdef __KERNEL__
/*
#define ic_header ic_data->hic_header
} xlog_in_core_t;
+/*
+ * The CIL context is used to aggregate per-transaction details as well be
+ * passed to the iclog for checkpoint post-commit processing. After being
+ * passed to the iclog, another context needs to be allocated for tracking the
+ * next set of transactions to be aggregated into a checkpoint.
+ */
+struct xfs_cil;
+
+struct xfs_cil_ctx {
+ struct xfs_cil *cil;
+ xfs_lsn_t sequence; /* chkpt sequence # */
+ xfs_lsn_t start_lsn; /* first LSN of chkpt commit */
+ xfs_lsn_t commit_lsn; /* chkpt commit record lsn */
+ struct xlog_ticket *ticket; /* chkpt ticket */
+ int nvecs; /* number of regions */
+ int space_used; /* aggregate size of regions */
+ struct list_head busy_extents; /* busy extents in chkpt */
+ struct xfs_log_vec *lv_chain; /* logvecs being pushed */
+ xfs_log_callback_t log_cb; /* completion callback hook. */
+ struct list_head committing; /* ctx committing list */
+};
+
+/*
+ * Committed Item List structure
+ *
+ * This structure is used to track log items that have been committed but not
+ * yet written into the log. It is used only when the delayed logging mount
+ * option is enabled.
+ *
+ * This structure tracks the list of committing checkpoint contexts so
+ * we can avoid the problem of having to hold out new transactions during a
+ * flush until we have a the commit record LSN of the checkpoint. We can
+ * traverse the list of committing contexts in xlog_cil_push_lsn() to find a
+ * sequence match and extract the commit LSN directly from there. If the
+ * checkpoint is still in the process of committing, we can block waiting for
+ * the commit LSN to be determined as well. This should make synchronous
+ * operations almost as efficient as the old logging methods.
+ */
+struct xfs_cil {
+ struct log *xc_log;
+ struct list_head xc_cil;
+ spinlock_t xc_cil_lock;
+ struct xfs_cil_ctx *xc_ctx;
+ struct rw_semaphore xc_ctx_lock;
+ struct list_head xc_committing;
+ sv_t xc_commit_wait;
+};
+
+/*
+ * The amount of log space we should the CIL to aggregate is difficult to size.
+ * Whatever we chose we have to make we can get a reservation for the log space
+ * effectively, that it is large enough to capture sufficient relogging to
+ * reduce log buffer IO significantly, but it is not too large for the log or
+ * induces too much latency when writing out through the iclogs. We track both
+ * space consumed and the number of vectors in the checkpoint context, so we
+ * need to decide which to use for limiting.
+ *
+ * Every log buffer we write out during a push needs a header reserved, which
+ * is at least one sector and more for v2 logs. Hence we need a reservation of
+ * at least 512 bytes per 32k of log space just for the LR headers. That means
+ * 16KB of reservation per megabyte of delayed logging space we will consume,
+ * plus various headers. The number of headers will vary based on the num of
+ * io vectors, so limiting on a specific number of vectors is going to result
+ * in transactions of varying size. IOWs, it is more consistent to track and
+ * limit space consumed in the log rather than by the number of objects being
+ * logged in order to prevent checkpoint ticket overruns.
+ *
+ * Further, use of static reservations through the log grant mechanism is
+ * problematic. It introduces a lot of complexity (e.g. reserve grant vs write
+ * grant) and a significant deadlock potential because regranting write space
+ * can block on log pushes. Hence if we have to regrant log space during a log
+ * push, we can deadlock.
+ *
+ * However, we can avoid this by use of a dynamic "reservation stealing"
+ * technique during transaction commit whereby unused reservation space in the
+ * transaction ticket is transferred to the CIL ctx commit ticket to cover the
+ * space needed by the checkpoint transaction. This means that we never need to
+ * specifically reserve space for the CIL checkpoint transaction, nor do we
+ * need to regrant space once the checkpoint completes. This also means the
+ * checkpoint transaction ticket is specific to the checkpoint context, rather
+ * than the CIL itself.
+ *
+ * With dynamic reservations, we can basically make up arbitrary limits for the
+ * checkpoint size so long as they don't violate any other size rules. Hence
+ * the initial maximum size for the checkpoint transaction will be set to a
+ * quarter of the log or 8MB, which ever is smaller. 8MB is an arbitrary limit
+ * right now based on the latency of writing out a large amount of data through
+ * the circular iclog buffers.
+ */
+
+#define XLOG_CIL_SPACE_LIMIT(log) \
+ (min((log->l_logsize >> 2), (8 * 1024 * 1024)))
+
/*
* The reservation head lsn is not made up of a cycle number and block number.
* Instead, it uses a cycle number and byte number. Logs don't expect to
/* The following fields don't need locking */
struct xfs_mount *l_mp; /* mount point */
struct xfs_ail *l_ailp; /* AIL log is working with */
+ struct xfs_cil *l_cilp; /* CIL log is working with */
struct xfs_buf *l_xbuf; /* extra buffer for log
* wrapping */
struct xfs_buftarg *l_targ; /* buftarg of log */
struct xfs_buf_cancel **l_buf_cancel_table;
int l_iclog_hsize; /* size of iclog header */
int l_iclog_heads; /* # of iclog header sectors */
- uint l_sectbb_log; /* log2 of sector size in BBs */
- uint l_sectbb_mask; /* sector size (in BBs)
- * alignment mask */
+ uint l_sectBBsize; /* sector size in BBs (2^n) */
int l_iclog_size; /* size of log in bytes */
int l_iclog_size_log; /* log power size of log */
int l_iclog_bufs; /* number of iclog buffers */
#define XLOG_FORCED_SHUTDOWN(log) ((log)->l_flags & XLOG_IO_ERROR)
-
/* common routines */
extern xfs_lsn_t xlog_assign_tail_lsn(struct xfs_mount *mp);
extern int xlog_recover(xlog_t *log);
extern int xlog_recover_finish(xlog_t *log);
extern void xlog_pack_data(xlog_t *log, xlog_in_core_t *iclog, int);
-extern kmem_zone_t *xfs_log_ticket_zone;
+extern kmem_zone_t *xfs_log_ticket_zone;
+struct xlog_ticket *xlog_ticket_alloc(struct log *log, int unit_bytes,
+ int count, char client, uint xflags,
+ int alloc_flags);
+
+
+static inline void
+xlog_write_adv_cnt(void **ptr, int *len, int *off, size_t bytes)
+{
+ *ptr += bytes;
+ *len -= bytes;
+ *off += bytes;
+}
+
+void xlog_print_tic_res(struct xfs_mount *mp, struct xlog_ticket *ticket);
+int xlog_write(struct log *log, struct xfs_log_vec *log_vector,
+ struct xlog_ticket *tic, xfs_lsn_t *start_lsn,
+ xlog_in_core_t **commit_iclog, uint flags);
+
+/*
+ * Committed Item List interfaces
+ */
+int xlog_cil_init(struct log *log);
+void xlog_cil_init_post_recovery(struct log *log);
+void xlog_cil_destroy(struct log *log);
+
+int xlog_cil_push(struct log *log, int push_now);
+xfs_lsn_t xlog_cil_push_lsn(struct log *log, xfs_lsn_t push_sequence);
/*
* Unmount record type is used as a pseudo transaction type for the ticket.
git.openpandora.org / pandora-kernel.git / blobdiff