diff options
Diffstat (limited to 'fs/gfs2/incore.h')
| -rw-r--r-- | fs/gfs2/incore.h | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h index d2ad817e089f..b96d39c28e17 100644 --- a/fs/gfs2/incore.h +++ b/fs/gfs2/incore.h @@ -65,6 +65,27 @@ struct gfs2_log_operations { #define GBF_FULL 1 +/** + * Clone bitmaps (bi_clone): + * + * - When a block is freed, we remember the previous state of the block in the + * clone bitmap, and only mark the block as free in the real bitmap. + * + * - When looking for a block to allocate, we check for a free block in the + * clone bitmap, and if no clone bitmap exists, in the real bitmap. + * + * - For allocating a block, we mark it as allocated in the real bitmap, and if + * a clone bitmap exists, also in the clone bitmap. + * + * - At the end of a log_flush, we copy the real bitmap into the clone bitmap + * to make the clone bitmap reflect the current allocation state. + * (Alternatively, we could remove the clone bitmap.) + * + * The clone bitmaps are in-core only, and is never written to disk. + * + * These steps ensure that blocks which have been freed in a transaction cannot + * be reallocated in that same transaction. + */ struct gfs2_bitmap { struct buffer_head *bi_bh; char *bi_clone; @@ -295,7 +316,6 @@ struct gfs2_blkreserv { struct rb_node rs_node; /* link to other block reservations */ struct gfs2_rbm rs_rbm; /* Start of reservation */ u32 rs_free; /* how many blocks are still free */ - u64 rs_inum; /* Inode number for reservation */ }; /* @@ -398,7 +418,6 @@ struct gfs2_inode { struct gfs2_holder i_gh; /* for prepare/commit_write only */ struct gfs2_qadata *i_qadata; /* quota allocation data */ struct gfs2_blkreserv i_res; /* rgrp multi-block reservation */ - struct gfs2_rgrpd *i_rgd; u64 i_goal; /* goal block for allocations */ struct rw_semaphore i_rw_mutex; struct list_head i_ordered; |