[XFS] Improve error handling for the zero-fsblock extent detection code.

[linux-2.6] / fs / xfs / xfs_log_priv.h

/*
 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef __XFS_LOG_PRIV_H__
#define __XFS_LOG_PRIV_H__

struct xfs_buf;
struct ktrace;
struct log;
struct xlog_ticket;
struct xfs_buf_cancel;
struct xfs_mount;

/*
 * Macros, structures, prototypes for internal log manager use.
 */

#define XLOG_MIN_ICLOGS         2
#define XLOG_MED_ICLOGS         4
#define XLOG_MAX_ICLOGS         8
#define XLOG_HEADER_MAGIC_NUM   0xFEEDbabe      /* Invalid cycle number */
#define XLOG_VERSION_1          1
#define XLOG_VERSION_2          2               /* Large IClogs, Log sunit */
#define XLOG_VERSION_OKBITS     (XLOG_VERSION_1 | XLOG_VERSION_2)
#define XLOG_RECORD_BSIZE       (16*1024)       /* eventually 32k */
#define XLOG_BIG_RECORD_BSIZE   (32*1024)       /* 32k buffers */
#define XLOG_MAX_RECORD_BSIZE   (256*1024)
#define XLOG_HEADER_CYCLE_SIZE  (32*1024)       /* cycle data in header */
#define XLOG_RECORD_BSHIFT      14              /* 16384 == 1 << 14 */
#define XLOG_BIG_RECORD_BSHIFT  15              /* 32k == 1 << 15 */
#define XLOG_MAX_RECORD_BSHIFT  18              /* 256k == 1 << 18 */
#define XLOG_BTOLSUNIT(log, b)  (((b)+(log)->l_mp->m_sb.sb_logsunit-1) / \
                                 (log)->l_mp->m_sb.sb_logsunit)
#define XLOG_LSUNITTOB(log, su) ((su) * (log)->l_mp->m_sb.sb_logsunit)

#define XLOG_HEADER_SIZE        512

#define XLOG_REC_SHIFT(log) \
        BTOBB(1 << (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) ? \
         XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))
#define XLOG_TOTAL_REC_SHIFT(log) \
        BTOBB(XLOG_MAX_ICLOGS << (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) ? \
         XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))

/*
 *  set lsns
 */

#define ASSIGN_ANY_LSN_HOST(lsn,cycle,block)  \
    { \
        (lsn) = ((xfs_lsn_t)(cycle)<<32)|(block); \
    }
#define ASSIGN_ANY_LSN_DISK(lsn,cycle,block)  \
    { \
        INT_SET(((uint *)&(lsn))[0], ARCH_CONVERT, (cycle)); \
        INT_SET(((uint *)&(lsn))[1], ARCH_CONVERT, (block)); \
    }
#define ASSIGN_LSN(lsn,log) \
    ASSIGN_ANY_LSN_DISK(lsn,(log)->l_curr_cycle,(log)->l_curr_block);

#define XLOG_SET(f,b)           (((f) & (b)) == (b))

#define GET_CYCLE(ptr, arch) \
    (INT_GET(*(uint *)(ptr), arch) == XLOG_HEADER_MAGIC_NUM ? \
         INT_GET(*((uint *)(ptr)+1), arch) : \
         INT_GET(*(uint *)(ptr), arch) \
    )

#define BLK_AVG(blk1, blk2)     ((blk1+blk2) >> 1)


#ifdef __KERNEL__

/*
 * get client id from packed copy.
 *
 * this hack is here because the xlog_pack code copies four bytes
 * of xlog_op_header containing the fields oh_clientid, oh_flags
 * and oh_res2 into the packed copy.
 *
 * later on this four byte chunk is treated as an int and the
 * client id is pulled out.
 *
 * this has endian issues, of course.
 */

#ifndef XFS_NATIVE_HOST
#define GET_CLIENT_ID(i,arch) \
    ((i) & 0xff)
#else
#define GET_CLIENT_ID(i,arch) \
    ((i) >> 24)
#endif

#define GRANT_LOCK(log)         mutex_spinlock(&(log)->l_grant_lock)
#define GRANT_UNLOCK(log, s)    mutex_spinunlock(&(log)->l_grant_lock, s)
#define LOG_LOCK(log)           mutex_spinlock(&(log)->l_icloglock)
#define LOG_UNLOCK(log, s)      mutex_spinunlock(&(log)->l_icloglock, s)

#define xlog_panic(args...)     cmn_err(CE_PANIC, ## args)
#define xlog_exit(args...)      cmn_err(CE_PANIC, ## args)
#define xlog_warn(args...)      cmn_err(CE_WARN, ## args)

/*
 * In core log state
 */
#define XLOG_STATE_ACTIVE    0x0001 /* Current IC log being written to */
#define XLOG_STATE_WANT_SYNC 0x0002 /* Want to sync this iclog; no more writes */
#define XLOG_STATE_SYNCING   0x0004 /* This IC log is syncing */
#define XLOG_STATE_DONE_SYNC 0x0008 /* Done syncing to disk */
#define XLOG_STATE_DO_CALLBACK \
                             0x0010 /* Process callback functions */
#define XLOG_STATE_CALLBACK  0x0020 /* Callback functions now */
#define XLOG_STATE_DIRTY     0x0040 /* Dirty IC log, not ready for ACTIVE status*/
#define XLOG_STATE_IOERROR   0x0080 /* IO error happened in sync'ing log */
#define XLOG_STATE_ALL       0x7FFF /* All possible valid flags */
#define XLOG_STATE_NOTUSED   0x8000 /* This IC log not being used */
#endif  /* __KERNEL__ */

/*
 * Flags to log operation header
 *
 * The first write of a new transaction will be preceded with a start
 * record, XLOG_START_TRANS.  Once a transaction is committed, a commit
 * record is written, XLOG_COMMIT_TRANS.  If a single region can not fit into
 * the remainder of the current active in-core log, it is split up into
 * multiple regions.  Each partial region will be marked with a
 * XLOG_CONTINUE_TRANS until the last one, which gets marked with XLOG_END_TRANS.
 *
 */
#define XLOG_START_TRANS        0x01    /* Start a new transaction */
#define XLOG_COMMIT_TRANS       0x02    /* Commit this transaction */
#define XLOG_CONTINUE_TRANS     0x04    /* Cont this trans into new region */
#define XLOG_WAS_CONT_TRANS     0x08    /* Cont this trans into new region */
#define XLOG_END_TRANS          0x10    /* End a continued transaction */
#define XLOG_UNMOUNT_TRANS      0x20    /* Unmount a filesystem transaction */

#ifdef __KERNEL__
/*
 * Flags to log ticket
 */
#define XLOG_TIC_INITED         0x1     /* has been initialized */
#define XLOG_TIC_PERM_RESERV    0x2     /* permanent reservation */
#define XLOG_TIC_IN_Q           0x4
#endif  /* __KERNEL__ */

#define XLOG_UNMOUNT_TYPE       0x556e  /* Un for Unmount */

/*
 * Flags for log structure
 */
#define XLOG_CHKSUM_MISMATCH    0x1     /* used only during recovery */
#define XLOG_ACTIVE_RECOVERY    0x2     /* in the middle of recovery */
#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__
/*
 * Below are states for covering allocation transactions.
 * By covering, we mean changing the h_tail_lsn in the last on-disk
 * log write such that no allocation transactions will be re-done during
 * recovery after a system crash. Recovery starts at the last on-disk
 * log write.
 *
 * These states are used to insert dummy log entries to cover
 * space allocation transactions which can undo non-transactional changes
 * after a crash. Writes to a file with space
 * already allocated do not result in any transactions. Allocations
 * might include space beyond the EOF. So if we just push the EOF a
 * little, the last transaction for the file could contain the wrong
 * size. If there is no file system activity, after an allocation
 * transaction, and the system crashes, the allocation transaction
 * will get replayed and the file will be truncated. This could
 * be hours/days/... after the allocation occurred.
 *
 * The fix for this is to do two dummy transactions when the
 * system is idle. We need two dummy transaction because the h_tail_lsn
 * in the log record header needs to point beyond the last possible
 * non-dummy transaction. The first dummy changes the h_tail_lsn to
 * the first transaction before the dummy. The second dummy causes
 * h_tail_lsn to point to the first dummy. Recovery starts at h_tail_lsn.
 *
 * These dummy transactions get committed when everything
 * is idle (after there has been some activity).
 *
 * There are 5 states used to control this.
 *
 *  IDLE -- no logging has been done on the file system or
 *              we are done covering previous transactions.
 *  NEED -- logging has occurred and we need a dummy transaction
 *              when the log becomes idle.
 *  DONE -- we were in the NEED state and have committed a dummy
 *              transaction.
 *  NEED2 -- we detected that a dummy transaction has gone to the
 *              on disk log with no other transactions.
 *  DONE2 -- we committed a dummy transaction when in the NEED2 state.
 *
 * There are two places where we switch states:
 *
 * 1.) In xfs_sync, when we detect an idle log and are in NEED or NEED2.
 *      We commit the dummy transaction and switch to DONE or DONE2,
 *      respectively. In all other states, we don't do anything.
 *
 * 2.) When we finish writing the on-disk log (xlog_state_clean_log).
 *
 *      No matter what state we are in, if this isn't the dummy
 *      transaction going out, the next state is NEED.
 *      So, if we aren't in the DONE or DONE2 states, the next state
 *      is NEED. We can't be finishing a write of the dummy record
 *      unless it was committed and the state switched to DONE or DONE2.
 *
 *      If we are in the DONE state and this was a write of the
 *              dummy transaction, we move to NEED2.
 *
 *      If we are in the DONE2 state and this was a write of the
 *              dummy transaction, we move to IDLE.
 *
 *
 * Writing only one dummy transaction can get appended to
 * one file space allocation. When this happens, the log recovery
 * code replays the space allocation and a file could be truncated.
 * This is why we have the NEED2 and DONE2 states before going idle.
 */

#define XLOG_STATE_COVER_IDLE   0
#define XLOG_STATE_COVER_NEED   1
#define XLOG_STATE_COVER_DONE   2
#define XLOG_STATE_COVER_NEED2  3
#define XLOG_STATE_COVER_DONE2  4

#define XLOG_COVER_OPS          5


/* Ticket reservation region accounting */ 
#define XLOG_TIC_LEN_MAX        15
#define XLOG_TIC_RESET_RES(t) ((t)->t_res_num = \
                                (t)->t_res_arr_sum = (t)->t_res_num_ophdrs = 0)
#define XLOG_TIC_ADD_OPHDR(t) ((t)->t_res_num_ophdrs++)
#define XLOG_TIC_ADD_REGION(t, len, type)                               \
        do {                                                            \
                if ((t)->t_res_num == XLOG_TIC_LEN_MAX) {               \
                        /* add to overflow and start again */           \
                        (t)->t_res_o_flow += (t)->t_res_arr_sum;        \
                        (t)->t_res_num = 0;                             \
                        (t)->t_res_arr_sum = 0;                         \
                }                                                       \
                (t)->t_res_arr[(t)->t_res_num].r_len = (len);           \
                (t)->t_res_arr[(t)->t_res_num].r_type = (type);         \
                (t)->t_res_arr_sum += (len);                            \
                (t)->t_res_num++;                                       \
        } while (0)

/*
 * Reservation region
 * As would be stored in xfs_log_iovec but without the i_addr which
 * we don't care about.
 */
typedef struct xlog_res {
        uint    r_len;  /* region length                :4 */
        uint    r_type; /* region's transaction type    :4 */
} xlog_res_t;

typedef struct xlog_ticket {
        sv_t               t_sema;       /* sleep on this semaphore      : 20 */
        struct xlog_ticket *t_next;      /*                              :4|8 */
        struct xlog_ticket *t_prev;      /*                              :4|8 */
        xlog_tid_t         t_tid;        /* transaction identifier       : 4  */
        int                t_curr_res;   /* current reservation in bytes : 4  */
        int                t_unit_res;   /* unit reservation in bytes    : 4  */
        char               t_ocnt;       /* original count               : 1  */
        char               t_cnt;        /* current count                : 1  */
        char               t_clientid;   /* who does this belong to;     : 1  */
        char               t_flags;      /* properties of reservation    : 1  */
        uint               t_trans_type; /* transaction type             : 4  */

        /* reservation array fields */
        uint               t_res_num;                    /* num in array : 4 */
        uint               t_res_num_ophdrs;             /* num op hdrs  : 4 */
        uint               t_res_arr_sum;                /* array sum    : 4 */
        uint               t_res_o_flow;                 /* sum overflow : 4 */
        xlog_res_t         t_res_arr[XLOG_TIC_LEN_MAX];  /* array of res : 8 * 15 */ 
} xlog_ticket_t;

#endif


typedef struct xlog_op_header {
        xlog_tid_t oh_tid;      /* transaction id of operation  :  4 b */
        int        oh_len;      /* bytes in data region         :  4 b */
        __uint8_t  oh_clientid; /* who sent me this             :  1 b */
        __uint8_t  oh_flags;    /*                              :  1 b */
        ushort     oh_res2;     /* 32 bit align                 :  2 b */
} xlog_op_header_t;


/* valid values for h_fmt */
#define XLOG_FMT_UNKNOWN  0
#define XLOG_FMT_LINUX_LE 1
#define XLOG_FMT_LINUX_BE 2
#define XLOG_FMT_IRIX_BE  3

/* our fmt */
#ifdef XFS_NATIVE_HOST
#define XLOG_FMT XLOG_FMT_LINUX_BE
#else
#define XLOG_FMT XLOG_FMT_LINUX_LE
#endif

typedef struct xlog_rec_header {
        uint      h_magicno;    /* log record (LR) identifier           :  4 */
        uint      h_cycle;      /* write cycle of log                   :  4 */
        int       h_version;    /* LR version                           :  4 */
        int       h_len;        /* len in bytes; should be 64-bit aligned: 4 */
        xfs_lsn_t h_lsn;        /* lsn of this LR                       :  8 */
        xfs_lsn_t h_tail_lsn;   /* lsn of 1st LR w/ buffers not committed: 8 */
        uint      h_chksum;     /* may not be used; non-zero if used    :  4 */
        int       h_prev_block; /* block number to previous LR          :  4 */
        int       h_num_logops; /* number of log operations in this LR  :  4 */
        uint      h_cycle_data[XLOG_HEADER_CYCLE_SIZE / BBSIZE];
        /* new fields */
        int       h_fmt;        /* format of log record                 :  4 */
        uuid_t    h_fs_uuid;    /* uuid of FS                           : 16 */
        int       h_size;       /* iclog size                           :  4 */
} xlog_rec_header_t;

typedef struct xlog_rec_ext_header {
        uint      xh_cycle;     /* write cycle of log                   : 4 */
        uint      xh_cycle_data[XLOG_HEADER_CYCLE_SIZE / BBSIZE]; /*    : 256 */
} xlog_rec_ext_header_t;

#ifdef __KERNEL__
/*
 * - A log record header is 512 bytes.  There is plenty of room to grow the
 *      xlog_rec_header_t into the reserved space.
 * - ic_data follows, so a write to disk can start at the beginning of
 *      the iclog.
 * - ic_forcesema is used to implement synchronous forcing of the iclog to disk.
 * - ic_next is the pointer to the next iclog in the ring.
 * - ic_bp is a pointer to the buffer used to write this incore log to disk.
 * - ic_log is a pointer back to the global log structure.
 * - ic_callback is a linked list of callback function/argument pairs to be
 *      called after an iclog finishes writing.
 * - ic_size is the full size of the header plus data.
 * - ic_offset is the current number of bytes written to in this iclog.
 * - ic_refcnt is bumped when someone is writing to the log.
 * - ic_state is the state of the iclog.
 */
typedef struct xlog_iclog_fields {
        sv_t                    ic_forcesema;
        sv_t                    ic_writesema;
        struct xlog_in_core     *ic_next;
        struct xlog_in_core     *ic_prev;
        struct xfs_buf          *ic_bp;
        struct log              *ic_log;
        xfs_log_callback_t      *ic_callback;
        xfs_log_callback_t      **ic_callback_tail;
#ifdef XFS_LOG_TRACE
        struct ktrace           *ic_trace;
#endif
        int                     ic_size;
        int                     ic_offset;
        int                     ic_refcnt;
        int                     ic_bwritecnt;
        ushort_t                ic_state;
        char                    *ic_datap;      /* pointer to iclog data */
} xlog_iclog_fields_t;

typedef union xlog_in_core2 {
        xlog_rec_header_t       hic_header;
        xlog_rec_ext_header_t   hic_xheader;
        char                    hic_sector[XLOG_HEADER_SIZE];
} xlog_in_core_2_t;

typedef struct xlog_in_core {
        xlog_iclog_fields_t     hic_fields;
        xlog_in_core_2_t        *hic_data;
} xlog_in_core_t;

/*
 * Defines to save our code from this glop.
 */
#define ic_forcesema    hic_fields.ic_forcesema
#define ic_writesema    hic_fields.ic_writesema
#define ic_next         hic_fields.ic_next
#define ic_prev         hic_fields.ic_prev
#define ic_bp           hic_fields.ic_bp
#define ic_log          hic_fields.ic_log
#define ic_callback     hic_fields.ic_callback
#define ic_callback_tail hic_fields.ic_callback_tail
#define ic_trace        hic_fields.ic_trace
#define ic_size         hic_fields.ic_size
#define ic_offset       hic_fields.ic_offset
#define ic_refcnt       hic_fields.ic_refcnt
#define ic_bwritecnt    hic_fields.ic_bwritecnt
#define ic_state        hic_fields.ic_state
#define ic_datap        hic_fields.ic_datap
#define ic_header       hic_data->hic_header

/*
 * 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
 * overflow 31 bits worth of byte offset, so using a byte number will mean
 * that round off problems won't occur when releasing partial reservations.
 */
typedef struct log {
        /* The following block of fields are changed while holding icloglock */
        sema_t                  l_flushsema;    /* iclog flushing semaphore */
        int                     l_flushcnt;     /* # of procs waiting on this
                                                 * sema */
        int                     l_ticket_cnt;   /* free ticket count */
        int                     l_ticket_tcnt;  /* total ticket count */
        int                     l_covered_state;/* state of "covering disk
                                                 * log entries" */
        xlog_ticket_t           *l_freelist;    /* free list of tickets */
        xlog_ticket_t           *l_unmount_free;/* kmem_free these addresses */
        xlog_ticket_t           *l_tail;        /* free list of tickets */
        xlog_in_core_t          *l_iclog;       /* head log queue       */
        lock_t                  l_icloglock;    /* grab to change iclog state */
        xfs_lsn_t               l_tail_lsn;     /* lsn of 1st LR with unflushed
                                                 * buffers */
        xfs_lsn_t               l_last_sync_lsn;/* lsn of last LR on disk */
        struct xfs_mount        *l_mp;          /* mount point */
        struct xfs_buf          *l_xbuf;        /* extra buffer for log
                                                 * wrapping */
        struct xfs_buftarg      *l_targ;        /* buftarg of log */
        xfs_daddr_t             l_logBBstart;   /* start block of log */
        int                     l_logsize;      /* size of log in bytes */
        int                     l_logBBsize;    /* size of log in BB chunks */
        int                     l_curr_cycle;   /* Cycle number of log writes */
        int                     l_prev_cycle;   /* Cycle number before last
                                                 * block increment */
        int                     l_curr_block;   /* current logical log block */
        int                     l_prev_block;   /* previous logical log block */
        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 */

        /* The following field are used for debugging; need to hold icloglock */
        char                    *l_iclog_bak[XLOG_MAX_ICLOGS];

        /* The following block of fields are changed while holding grant_lock */
        lock_t                  l_grant_lock;
        xlog_ticket_t           *l_reserve_headq;
        xlog_ticket_t           *l_write_headq;
        int                     l_grant_reserve_cycle;
        int                     l_grant_reserve_bytes;
        int                     l_grant_write_cycle;
        int                     l_grant_write_bytes;

        /* The following fields don't need locking */
#ifdef XFS_LOG_TRACE
        struct ktrace           *l_trace;
        struct ktrace           *l_grant_trace;
#endif
        uint                    l_flags;
        uint                    l_quotaoffs_flag; /* XFS_DQ_*, for QUOTAOFFs */
        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 */
} xlog_t;

#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_find_tail(xlog_t  *log,
                                xfs_daddr_t *head_blk,
                                xfs_daddr_t *tail_blk);
extern int       xlog_recover(xlog_t *log);
extern int       xlog_recover_finish(xlog_t *log, int mfsi_flags);
extern void      xlog_pack_data(xlog_t *log, xlog_in_core_t *iclog, int);
extern void      xlog_recover_process_iunlinks(xlog_t *log);

extern struct xfs_buf *xlog_get_bp(xlog_t *, int);
extern void      xlog_put_bp(struct xfs_buf *);
extern int       xlog_bread(xlog_t *, xfs_daddr_t, int, struct xfs_buf *);

/* iclog tracing */
#define XLOG_TRACE_GRAB_FLUSH  1
#define XLOG_TRACE_REL_FLUSH   2
#define XLOG_TRACE_SLEEP_FLUSH 3
#define XLOG_TRACE_WAKE_FLUSH  4

#endif  /* __KERNEL__ */

#endif  /* __XFS_LOG_PRIV_H__ */