Return-Path: Received: from int-mailstore01.merit.edu ([207.75.116.232]:53486 "EHLO int-mailstore01.merit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755760Ab1FGR2o (ORCPT ); Tue, 7 Jun 2011 13:28:44 -0400 Date: Tue, 7 Jun 2011 13:28:42 -0400 From: Jim Rees To: Benny Halevy Cc: linux-nfs@vger.kernel.org, peter honeyman Subject: [PATCH 23/88] pnfsblock: merge extents Message-ID: <698910d29d0a96738d314a6af69abcf0b9c95428.1307464382.git.rees@umich.edu> References: Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 From: Fred Isaman Replace a stub, so that extents underlying the layouts are properly added, merged, or ignored as necessary. Signed-off-by: Fred Isaman [pnfsblock: delete the new node before put it] Signed-off-by: Mingyang Guo Signed-off-by: Benny Halevy --- fs/nfs/blocklayout/blocklayout.h | 10 +++ fs/nfs/blocklayout/blocklayoutdev.c | 19 +++++- fs/nfs/blocklayout/extents.c | 128 +++++++++++++++++++++++++++++++++++ 3 files changed, 154 insertions(+), 3 deletions(-) diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h index f91939d..13fc0e2 100644 --- a/fs/nfs/blocklayout/blocklayout.h +++ b/fs/nfs/blocklayout/blocklayout.h @@ -135,6 +135,14 @@ enum extentclass4 { EXTENT_LISTS = 2, }; +static inline int choose_list(enum exstate4 state) +{ + if (state == PNFS_BLOCK_READ_DATA || state == PNFS_BLOCK_NONE_DATA) + return RO_EXTENT; + else + return RW_EXTENT; +} + struct pnfs_block_layout { struct pnfs_inval_markings bl_inval; /* tracks INVAL->RW transition */ spinlock_t bl_ext_lock; /* Protects list manipulation */ @@ -197,4 +205,6 @@ void free_block_dev(struct pnfs_block_dev *bdev); /* extents.c */ void put_extent(struct pnfs_block_extent *be); struct pnfs_block_extent *alloc_extent(void); +int add_and_merge_extent(struct pnfs_block_layout *bl, + struct pnfs_block_extent *new); #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */ diff --git a/fs/nfs/blocklayout/blocklayoutdev.c b/fs/nfs/blocklayout/blocklayoutdev.c index 77190fd..ac5c117 100644 --- a/fs/nfs/blocklayout/blocklayoutdev.c +++ b/fs/nfs/blocklayout/blocklayoutdev.c @@ -642,7 +642,7 @@ nfs4_blk_process_layoutget(struct pnfs_layout_type *lo, uint32_t *end = (uint32_t *)((char *)lgr->layout.buf + lgr->layout.len); int i, status = -EIO; uint32_t count; - struct pnfs_block_extent *be = NULL; + struct pnfs_block_extent *be = NULL, *save; uint64_t tmp; /* Used by READSECTOR */ struct layout_verification lv = { .mode = lgr->lseg.iomode, @@ -706,9 +706,22 @@ nfs4_blk_process_layoutget(struct pnfs_layout_type *lo, /* Extents decoded properly, now try to merge them in to * existing layout extents. */ - /* STUB - instead we just throw them away */ + spin_lock(&bl->bl_ext_lock); + list_for_each_entry_safe(be, save, &extents, be_node) { + list_del(&be->be_node); + status = add_and_merge_extent(bl, be); + if (status) { + spin_unlock(&bl->bl_ext_lock); + /* This is a fairly catastrophic error, as the + * entire layout extent lists are now corrupted. + * We should have some way to distinguish this. + */ + be = NULL; + goto out_err; + } + } + spin_unlock(&bl->bl_ext_lock); status = 0; - goto out_err; out: dprintk("%s returns %i\n", __func__, status); return status; diff --git a/fs/nfs/blocklayout/extents.c b/fs/nfs/blocklayout/extents.c index a952d39..ce7b6f7 100644 --- a/fs/nfs/blocklayout/extents.c +++ b/fs/nfs/blocklayout/extents.c @@ -33,6 +33,17 @@ #include "blocklayout.h" #define NFSDBG_FACILITY NFSDBG_PNFS_LD +static void print_bl_extent(struct pnfs_block_extent *be) +{ + dprintk("PRINT EXTENT extent %p\n", be); + if (be) { + dprintk(" be_f_offset %llu\n", (u64)be->be_f_offset); + dprintk(" be_length %llu\n", (u64)be->be_length); + dprintk(" be_v_offset %llu\n", (u64)be->be_v_offset); + dprintk(" be_state %d\n", be->be_state); + } +} + static void destroy_extent(struct kref *kref) { @@ -65,3 +76,120 @@ struct pnfs_block_extent *alloc_extent(void) be->be_inval = NULL; return be; } + +void print_elist(struct list_head *list) +{ + struct pnfs_block_extent *be; + dprintk("****************\n"); + dprintk("Extent list looks like:\n"); + list_for_each_entry(be, list, be_node) { + print_bl_extent(be); + } + dprintk("****************\n"); +} + +static inline int +extents_consistent(struct pnfs_block_extent *old, struct pnfs_block_extent *new) +{ + /* Note this assumes new->be_f_offset >= old->be_f_offset */ + return (new->be_state == old->be_state) && + ((new->be_state == PNFS_BLOCK_NONE_DATA) || + ((new->be_v_offset - old->be_v_offset == + new->be_f_offset - old->be_f_offset) && + new->be_mdev == old->be_mdev)); +} + +/* Adds new to appropriate list in bl, modifying new and removing existing + * extents as appropriate to deal with overlaps. + * + * See find_get_extent for list constraints. + * + * Refcount on new is already set. If end up not using it, or error out, + * need to put the reference. + * + * Lock is held by caller. + */ +int +add_and_merge_extent(struct pnfs_block_layout *bl, + struct pnfs_block_extent *new) +{ + struct pnfs_block_extent *be, *tmp; + sector_t end = new->be_f_offset + new->be_length; + struct list_head *list; + + dprintk("%s enter with be=%p\n", __func__, new); + print_bl_extent(new); + list = &bl->bl_extents[choose_list(new->be_state)]; + print_elist(list); + + /* Scan for proper place to insert, extending new to the left + * as much as possible. + */ + list_for_each_entry_safe(be, tmp, list, be_node) { + if (new->be_f_offset < be->be_f_offset) + break; + if (end <= be->be_f_offset + be->be_length) { + /* new is a subset of existing be*/ + if (extents_consistent(be, new)) { + dprintk("%s: new is subset, ignoring\n", + __func__); + put_extent(new); + return 0; + } else + goto out_err; + } else if (new->be_f_offset <= + be->be_f_offset + be->be_length) { + /* new overlaps or abuts existing be */ + if (extents_consistent(be, new)) { + /* extend new to fully replace be */ + new->be_length += new->be_f_offset - + be->be_f_offset; + new->be_f_offset = be->be_f_offset; + new->be_v_offset = be->be_v_offset; + dprintk("%s: removing %p\n", __func__, be); + list_del(&be->be_node); + put_extent(be); + } else if (new->be_f_offset != + be->be_f_offset + be->be_length) + goto out_err; + } + } + /* Note that if we never hit the above break, be will not point to a + * valid extent. However, in that case &be->be_node==list. + */ + list_add_tail(&new->be_node, &be->be_node); + dprintk("%s: inserting new\n", __func__); + print_elist(list); + /* Scan forward for overlaps. If we find any, extend new and + * remove the overlapped extent. + */ + be = list_prepare_entry(new, list, be_node); + list_for_each_entry_safe_continue(be, tmp, list, be_node) { + if (end < be->be_f_offset) + break; + /* new overlaps or abuts existing be */ + if (extents_consistent(be, new)) { + if (end < be->be_f_offset + be->be_length) { + /* extend new to fully cover be */ + end = be->be_f_offset + be->be_length; + new->be_length = end - new->be_f_offset; + } + dprintk("%s: removing %p\n", __func__, be); + list_del(&be->be_node); + put_extent(be); + } else if (end != be->be_f_offset) { + list_del(&new->be_node); + goto out_err; + } + } + dprintk("%s: after merging\n", __func__); + print_elist(list); + /* STUB - The per-list consistency checks have all been done, + * should now check cross-list consistency. + */ + return 0; + + out_err: + put_extent(new); + return -EIO; +} -- 1.7.4.1