diff options
Diffstat (limited to 'fs/gfs2')
| -rw-r--r-- | fs/gfs2/log.c | 162 | ||||
| -rw-r--r-- | fs/gfs2/log.h | 7 | ||||
| -rw-r--r-- | fs/gfs2/trans.c | 4 |
3 files changed, 104 insertions, 69 deletions
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c index 0c28ddd0e410..913150e60f52 100644 --- a/fs/gfs2/log.c +++ b/fs/gfs2/log.c @@ -447,15 +447,42 @@ void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks) } /** - * gfs2_log_reserve - Make a log reservation + * __gfs2_log_try_reserve - Try to make a log reservation + * @sdp: The GFS2 superblock + * @blks: The number of blocks to reserve + * @taboo_blks: The number of blocks to leave free + * + * Try to do the same as __gfs2_log_reserve(), but fail if no more log + * space is immediately available. + */ +static bool __gfs2_log_try_reserve(struct gfs2_sbd *sdp, unsigned int blks, + unsigned int taboo_blks) +{ + unsigned wanted = blks + taboo_blks; + unsigned int free_blocks; + + free_blocks = atomic_read(&sdp->sd_log_blks_free); + while (free_blocks >= wanted) { + if (atomic_try_cmpxchg(&sdp->sd_log_blks_free, &free_blocks, + free_blocks - blks)) { + trace_gfs2_log_blocks(sdp, -blks); + return true; + } + } + return false; +} + +/** + * __gfs2_log_reserve - Make a log reservation * @sdp: The GFS2 superblock * @blks: The number of blocks to reserve + * @taboo_blks: The number of blocks to leave free * - * Note that we never give out the last few blocks of the journal. Thats - * due to the fact that there is a small number of header blocks - * associated with each log flush. The exact number can't be known until - * flush time, so we ensure that we have just enough free blocks at all - * times to avoid running out during a log flush. + * @taboo_blks is set to 0 for logd, and to GFS2_LOG_FLUSH_MIN_BLOCKS + * for all other processes. This ensures that when the log is almost full, + * logd will still be able to call gfs2_log_flush one more time without + * blocking, which will advance the tail and make some more log space + * available. * * We no longer flush the log here, instead we wake up logd to do that * for us. To avoid the thundering herd and to ensure that we deal fairly @@ -464,19 +491,12 @@ void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks) * wake the next waiter on the list. */ -void gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) +static void __gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks, + unsigned int taboo_blks) { - unsigned reserved_blks = 7 * (4096 / sdp->sd_vfs->s_blocksize); - unsigned wanted = blks + reserved_blks; + unsigned wanted = blks + taboo_blks; unsigned int free_blocks; - free_blocks = atomic_read(&sdp->sd_log_blks_free); - while (free_blocks >= wanted) { - if (atomic_try_cmpxchg(&sdp->sd_log_blks_free, &free_blocks, - free_blocks - blks)) - return; - } - atomic_add(blks, &sdp->sd_log_blks_needed); for (;;) { if (current != sdp->sd_logd_process) @@ -499,6 +519,19 @@ reserved: } /** + * gfs2_log_reserve - Make a log reservation + * @sdp: The GFS2 superblock + * @blks: The number of blocks to reserve + */ + +void gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) +{ + if (__gfs2_log_try_reserve(sdp, blks, GFS2_LOG_FLUSH_MIN_BLOCKS)) + return; + __gfs2_log_reserve(sdp, blks, GFS2_LOG_FLUSH_MIN_BLOCKS); +} + +/** * log_distance - Compute distance between two journal blocks * @sdp: The GFS2 superblock * @newer: The most recent journal block of the pair @@ -545,7 +578,7 @@ static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer */ static unsigned int calc_reserved(struct gfs2_sbd *sdp) { - unsigned int reserved = 0; + unsigned int reserved = GFS2_LOG_FLUSH_MIN_BLOCKS; unsigned int blocks; struct gfs2_trans *tr = sdp->sd_log_tr; @@ -557,10 +590,7 @@ static unsigned int calc_reserved(struct gfs2_sbd *sdp) } if (sdp->sd_log_committed_revoke > 0) - reserved += gfs2_struct2blk(sdp, sdp->sd_log_committed_revoke); - /* One for the overall header */ - if (reserved) - reserved++; + reserved += gfs2_struct2blk(sdp, sdp->sd_log_committed_revoke) - 1; return reserved; } @@ -708,29 +738,8 @@ void gfs2_flush_revokes(struct gfs2_sbd *sdp) max_revokes += roundup(sdp->sd_log_num_revoke - sdp->sd_ldptrs, sdp->sd_inptrs); max_revokes -= sdp->sd_log_num_revoke; - if (!sdp->sd_log_num_revoke) { - atomic_dec(&sdp->sd_log_blks_free); - /* If no blocks have been reserved, we need to also - * reserve a block for the header */ - if (!sdp->sd_log_blks_reserved) { - atomic_dec(&sdp->sd_log_blks_free); - trace_gfs2_log_blocks(sdp, -2); - } else { - trace_gfs2_log_blocks(sdp, -1); - } - } gfs2_ail1_empty(sdp, max_revokes); gfs2_log_unlock(sdp); - - if (!sdp->sd_log_num_revoke) { - atomic_inc(&sdp->sd_log_blks_free); - if (!sdp->sd_log_blks_reserved) { - atomic_inc(&sdp->sd_log_blks_free); - trace_gfs2_log_blocks(sdp, 2); - } else { - trace_gfs2_log_blocks(sdp, 1); - } - } } /** @@ -843,6 +852,7 @@ static void log_write_header(struct gfs2_sbd *sdp, u32 flags) gfs2_log_incr_head(sdp); log_flush_wait(sdp); log_pull_tail(sdp); + gfs2_log_update_head(sdp); } /** @@ -942,10 +952,14 @@ static void trans_drain(struct gfs2_trans *tr) void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) { struct gfs2_trans *tr = NULL; + unsigned int reserved_blocks = 0, used_blocks = 0; enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state); + unsigned int first_log_head; down_write(&sdp->sd_log_flush_lock); + trace_gfs2_log_flush(sdp, 1, flags); +repeat: /* * Do this check while holding the log_flush_lock to prevent new * buffers from being added to the ail via gfs2_pin() @@ -956,22 +970,41 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) /* Log might have been flushed while we waited for the flush lock */ if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) goto out; - trace_gfs2_log_flush(sdp, 1, flags); - if (flags & GFS2_LOG_HEAD_FLUSH_SHUTDOWN) - clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags); + first_log_head = sdp->sd_log_head; + sdp->sd_log_flush_head = first_log_head; - sdp->sd_log_flush_head = sdp->sd_log_head; tr = sdp->sd_log_tr; - if (tr) { - sdp->sd_log_tr = NULL; - tr->tr_first = sdp->sd_log_flush_head; - if (unlikely (state == SFS_FROZEN)) - if (gfs2_assert_withdraw_delayed(sdp, - !tr->tr_num_buf_new && !tr->tr_num_databuf_new)) - goto out_withdraw; + if (tr || sdp->sd_log_num_revoke) { + if (reserved_blocks) + gfs2_log_release(sdp, reserved_blocks); + reserved_blocks = sdp->sd_log_blks_reserved; + if (tr) { + sdp->sd_log_tr = NULL; + tr->tr_first = first_log_head; + if (unlikely (state == SFS_FROZEN)) + if (gfs2_assert_withdraw_delayed(sdp, + !tr->tr_num_buf_new && !tr->tr_num_databuf_new)) + goto out_withdraw; + } + } else if (!reserved_blocks) { + unsigned int taboo_blocks = GFS2_LOG_FLUSH_MIN_BLOCKS; + + reserved_blocks = GFS2_LOG_FLUSH_MIN_BLOCKS; + if (current == sdp->sd_logd_process) + taboo_blocks = 0; + + if (!__gfs2_log_try_reserve(sdp, reserved_blocks, taboo_blocks)) { + up_write(&sdp->sd_log_flush_lock); + __gfs2_log_reserve(sdp, reserved_blocks, taboo_blocks); + down_write(&sdp->sd_log_flush_lock); + goto repeat; + } } + if (flags & GFS2_LOG_HEAD_FLUSH_SHUTDOWN) + clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags); + if (unlikely(state == SFS_FROZEN)) if (gfs2_assert_withdraw_delayed(sdp, !sdp->sd_log_num_revoke)) goto out_withdraw; @@ -993,8 +1026,6 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) log_flush_wait(sdp); log_write_header(sdp, flags); } else if (sdp->sd_log_tail != sdp->sd_log_flush_tail && !sdp->sd_log_idle) { - atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */ - trace_gfs2_log_blocks(sdp, -1); log_write_header(sdp, flags); } if (gfs2_withdrawn(sdp)) @@ -1002,7 +1033,6 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) lops_after_commit(sdp, tr); gfs2_log_lock(sdp); - gfs2_log_update_head(sdp); sdp->sd_log_blks_reserved = 0; sdp->sd_log_committed_revoke = 0; @@ -1019,10 +1049,7 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) empty_ail1_list(sdp); if (gfs2_withdrawn(sdp)) goto out_withdraw; - atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */ - trace_gfs2_log_blocks(sdp, -1); log_write_header(sdp, flags); - gfs2_log_update_head(sdp); } if (flags & (GFS2_LOG_HEAD_FLUSH_SHUTDOWN | GFS2_LOG_HEAD_FLUSH_FREEZE)) @@ -1032,12 +1059,17 @@ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) } out_end: - trace_gfs2_log_flush(sdp, 0, flags); + used_blocks = log_distance(sdp, sdp->sd_log_flush_head, first_log_head); + if (gfs2_assert_withdraw_delayed(sdp, used_blocks <= reserved_blocks)) + goto out; out: + if (used_blocks != reserved_blocks) + gfs2_log_release(sdp, reserved_blocks - used_blocks); up_write(&sdp->sd_log_flush_lock); gfs2_trans_free(sdp, tr); if (gfs2_withdrawing(sdp)) gfs2_withdraw(sdp); + trace_gfs2_log_flush(sdp, 0, flags); return; out_withdraw: @@ -1150,15 +1182,11 @@ static void gfs2_log_shutdown(struct gfs2_sbd *sdp) gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke); gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list)); - sdp->sd_log_flush_head = sdp->sd_log_head; - log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT | GFS2_LFC_SHUTDOWN); + log_pull_tail(sdp); gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail); gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list)); - - gfs2_log_update_head(sdp); - sdp->sd_log_tail = sdp->sd_log_head; } static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp) @@ -1213,7 +1241,7 @@ int gfs2_logd(void *data) if (gfs2_jrnl_flush_reqd(sdp) || t == 0) { gfs2_ail1_empty(sdp, 0); gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL | - GFS2_LFC_LOGD_JFLUSH_REQD); + GFS2_LFC_LOGD_JFLUSH_REQD); } if (gfs2_ail_flush_reqd(sdp)) { @@ -1221,7 +1249,7 @@ int gfs2_logd(void *data) gfs2_ail1_wait(sdp); gfs2_ail1_empty(sdp, 0); gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL | - GFS2_LFC_LOGD_AIL_FLUSH_REQD); + GFS2_LFC_LOGD_AIL_FLUSH_REQD); } t = gfs2_tune_get(sdp, gt_logd_secs) * HZ; diff --git a/fs/gfs2/log.h b/fs/gfs2/log.h index b36a3539f352..e7f4a8d6be64 100644 --- a/fs/gfs2/log.h +++ b/fs/gfs2/log.h @@ -13,6 +13,13 @@ #include "incore.h" #include "inode.h" +/* + * The minimum amount of log space required for a log flush is one block for + * revokes and one block for the log header. Log flushes other than + * GFS2_LOG_HEAD_FLUSH_NORMAL may write one or two more log headers. + */ +#define GFS2_LOG_FLUSH_MIN_BLOCKS 4 + /** * gfs2_log_lock - acquire the right to mess with the log manager * @sdp: the filesystem diff --git a/fs/gfs2/trans.c b/fs/gfs2/trans.c index f73d6b8f3b53..231ca1a41a73 100644 --- a/fs/gfs2/trans.c +++ b/fs/gfs2/trans.c @@ -53,7 +53,7 @@ int __gfs2_trans_begin(struct gfs2_trans *tr, struct gfs2_sbd *sdp, tr->tr_ip = ip; tr->tr_blocks = blocks; tr->tr_revokes = revokes; - tr->tr_reserved = 1; + tr->tr_reserved = GFS2_LOG_FLUSH_MIN_BLOCKS; if (blocks) { /* * The reserved blocks are either used for data or metadata. @@ -63,7 +63,7 @@ int __gfs2_trans_begin(struct gfs2_trans *tr, struct gfs2_sbd *sdp, tr->tr_reserved += blocks + 1 + DIV_ROUND_UP(blocks - 1, databuf_limit(sdp)); } if (revokes) - tr->tr_reserved += gfs2_struct2blk(sdp, revokes); + tr->tr_reserved += gfs2_struct2blk(sdp, revokes) - 1; INIT_LIST_HEAD(&tr->tr_databuf); INIT_LIST_HEAD(&tr->tr_buf); INIT_LIST_HEAD(&tr->tr_list); |