From 7ac687d9e047b3fa335f04e18c7188db6a170334 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Fri, 25 Nov 2011 23:14:28 +0800 Subject: btrfs: remove the second argument of k[un]map_atomic() Signed-off-by: Cong Wang --- fs/btrfs/extent_io.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index a55fbe6252de..2862454bcdb3 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2546,10 +2546,10 @@ static int __extent_read_full_page(struct extent_io_tree *tree, if (zero_offset) { iosize = PAGE_CACHE_SIZE - zero_offset; - userpage = kmap_atomic(page, KM_USER0); + userpage = kmap_atomic(page); memset(userpage + zero_offset, 0, iosize); flush_dcache_page(page); - kunmap_atomic(userpage, KM_USER0); + kunmap_atomic(userpage); } } while (cur <= end) { @@ -2558,10 +2558,10 @@ static int __extent_read_full_page(struct extent_io_tree *tree, struct extent_state *cached = NULL; iosize = PAGE_CACHE_SIZE - pg_offset; - userpage = kmap_atomic(page, KM_USER0); + userpage = kmap_atomic(page); memset(userpage + pg_offset, 0, iosize); flush_dcache_page(page); - kunmap_atomic(userpage, KM_USER0); + kunmap_atomic(userpage); set_extent_uptodate(tree, cur, cur + iosize - 1, &cached, GFP_NOFS); unlock_extent_cached(tree, cur, cur + iosize - 1, @@ -2607,10 +2607,10 @@ static int __extent_read_full_page(struct extent_io_tree *tree, char *userpage; struct extent_state *cached = NULL; - userpage = kmap_atomic(page, KM_USER0); + userpage = kmap_atomic(page); memset(userpage + pg_offset, 0, iosize); flush_dcache_page(page); - kunmap_atomic(userpage, KM_USER0); + kunmap_atomic(userpage); set_extent_uptodate(tree, cur, cur + iosize - 1, &cached, GFP_NOFS); @@ -2756,10 +2756,10 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc, if (page->index == end_index) { char *userpage; - userpage = kmap_atomic(page, KM_USER0); + userpage = kmap_atomic(page); memset(userpage + pg_offset, 0, PAGE_CACHE_SIZE - pg_offset); - kunmap_atomic(userpage, KM_USER0); + kunmap_atomic(userpage); flush_dcache_page(page); } pg_offset = 0; -- cgit v1.2.3 From c2d904e086b6f707b73bf065e4d18ded4b86ae9e Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Mon, 3 Oct 2011 23:22:32 -0400 Subject: btrfs: Catch locking failures in {set,clear,convert}_extent_bit The *_state functions can only return 0 or -EEXIST. This patch addresses the cases where those functions returning -EEXIST represent a locking failure. It handles them by panicking with an appropriate error message. Signed-off-by: Jeff Mahoney --- fs/btrfs/extent_io.c | 58 ++++++++++++++++++++++++++++++++++------------------ 1 file changed, 38 insertions(+), 20 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index a55fbe6252de..601f23bddea8 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -53,6 +53,12 @@ struct extent_page_data { unsigned int sync_io:1; }; +static inline struct btrfs_fs_info * +tree_fs_info(struct extent_io_tree *tree) +{ + return btrfs_sb(tree->mapping->host->i_sb); +} + int __init extent_io_init(void) { extent_state_cache = kmem_cache_create("extent_state", @@ -439,6 +445,13 @@ alloc_extent_state_atomic(struct extent_state *prealloc) return prealloc; } +void extent_io_tree_panic(struct extent_io_tree *tree, int err) +{ + btrfs_panic(tree_fs_info(tree), err, "Locking error: " + "Extent tree was modified by another " + "thread while locked."); +} + /* * clear some bits on a range in the tree. This may require splitting * or inserting elements in the tree, so the gfp mask is used to @@ -542,7 +555,9 @@ hit_next: prealloc = alloc_extent_state_atomic(prealloc); BUG_ON(!prealloc); err = split_state(tree, state, prealloc, start); - BUG_ON(err == -EEXIST); + if (err) + extent_io_tree_panic(tree, err); + prealloc = NULL; if (err) goto out; @@ -564,7 +579,9 @@ hit_next: prealloc = alloc_extent_state_atomic(prealloc); BUG_ON(!prealloc); err = split_state(tree, state, prealloc, end + 1); - BUG_ON(err == -EEXIST); + if (err) + extent_io_tree_panic(tree, err); + if (wake) wake_up(&state->wq); @@ -742,8 +759,10 @@ again: prealloc = alloc_extent_state_atomic(prealloc); BUG_ON(!prealloc); err = insert_state(tree, prealloc, start, end, &bits); + if (err) + extent_io_tree_panic(tree, err); + prealloc = NULL; - BUG_ON(err == -EEXIST); goto out; } state = rb_entry(node, struct extent_state, rb_node); @@ -809,7 +828,9 @@ hit_next: prealloc = alloc_extent_state_atomic(prealloc); BUG_ON(!prealloc); err = split_state(tree, state, prealloc, start); - BUG_ON(err == -EEXIST); + if (err) + extent_io_tree_panic(tree, err); + prealloc = NULL; if (err) goto out; @@ -846,12 +867,9 @@ hit_next: */ err = insert_state(tree, prealloc, start, this_end, &bits); - BUG_ON(err == -EEXIST); - if (err) { - free_extent_state(prealloc); - prealloc = NULL; - goto out; - } + if (err) + extent_io_tree_panic(tree, err); + cache_state(prealloc, cached_state); prealloc = NULL; start = this_end + 1; @@ -873,7 +891,8 @@ hit_next: prealloc = alloc_extent_state_atomic(prealloc); BUG_ON(!prealloc); err = split_state(tree, state, prealloc, end + 1); - BUG_ON(err == -EEXIST); + if (err) + extent_io_tree_panic(tree, err); set_state_bits(tree, prealloc, &bits); cache_state(prealloc, cached_state); @@ -946,7 +965,8 @@ again: } err = insert_state(tree, prealloc, start, end, &bits); prealloc = NULL; - BUG_ON(err == -EEXIST); + if (err) + extent_io_tree_panic(tree, err); goto out; } state = rb_entry(node, struct extent_state, rb_node); @@ -1002,7 +1022,8 @@ hit_next: goto out; } err = split_state(tree, state, prealloc, start); - BUG_ON(err == -EEXIST); + if (err) + extent_io_tree_panic(tree, err); prealloc = NULL; if (err) goto out; @@ -1041,12 +1062,8 @@ hit_next: */ err = insert_state(tree, prealloc, start, this_end, &bits); - BUG_ON(err == -EEXIST); - if (err) { - free_extent_state(prealloc); - prealloc = NULL; - goto out; - } + if (err) + extent_io_tree_panic(tree, err); prealloc = NULL; start = this_end + 1; goto search_again; @@ -1065,7 +1082,8 @@ hit_next: } err = split_state(tree, state, prealloc, end + 1); - BUG_ON(err == -EEXIST); + if (err) + extent_io_tree_panic(tree, err); set_state_bits(tree, prealloc, &bits); clear_state_bit(tree, prealloc, &clear_bits, 0); -- cgit v1.2.3 From 6763af84a69f23c1c79f00720982e74fcff4d1f3 Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Thu, 1 Mar 2012 14:56:29 +0100 Subject: btrfs: Remove set bits return from clear_extent_bit There is only one caller of clear_extent_bit that checks the return value and it only checks if it's negative. Since there are no users of the returned bits functionality of clear_extent_bit, stop returning it and avoid complicating error handling. Signed-off-by: Jeff Mahoney --- fs/btrfs/extent_io.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 601f23bddea8..a4a7a18cdd3d 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -462,8 +462,7 @@ void extent_io_tree_panic(struct extent_io_tree *tree, int err) * * the range [start, end] is inclusive. * - * This takes the tree lock, and returns < 0 on error, > 0 if any of the - * bits were already set, or zero if none of the bits were already set. + * This takes the tree lock, and returns 0 on success and < 0 on error. */ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits, int wake, int delete, @@ -477,7 +476,6 @@ int clear_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, struct rb_node *node; u64 last_end; int err; - int set = 0; int clear = 0; if (delete) @@ -562,7 +560,7 @@ hit_next: if (err) goto out; if (state->end <= end) { - set |= clear_state_bit(tree, state, &bits, wake); + clear_state_bit(tree, state, &bits, wake); if (last_end == (u64)-1) goto out; start = last_end + 1; @@ -585,13 +583,13 @@ hit_next: if (wake) wake_up(&state->wq); - set |= clear_state_bit(tree, prealloc, &bits, wake); + clear_state_bit(tree, prealloc, &bits, wake); prealloc = NULL; goto out; } - set |= clear_state_bit(tree, state, &bits, wake); + clear_state_bit(tree, state, &bits, wake); next: if (last_end == (u64)-1) goto out; @@ -608,7 +606,7 @@ out: if (prealloc) free_extent_state(prealloc); - return set; + return 0; search_again: if (start > end) -- cgit v1.2.3 From 3444a97255de907f32562741fb6d104620b9fce3 Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Mon, 3 Oct 2011 23:23:13 -0400 Subject: btrfs: Factor out tree->ops->merge_bio_hook call In submit_extent_page, there's a visually noisy if statement that, in the midst of other conditions, does the tree dependency for tree->ops and tree->ops->merge_bio_hook before calling it, and then another condition afterwards. If an error is returned from merge_bio_hook, there's no way to catch it. It's considered a routine "1" return value instead of a failure. This patch factors out the dependency check into a new local merge_bio routine and BUG's on an error. The if statement is less noisy as a side- effect. Signed-off-by: Jeff Mahoney --- fs/btrfs/extent_io.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index a4a7a18cdd3d..c342e923ea41 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2429,6 +2429,19 @@ static int submit_one_bio(int rw, struct bio *bio, int mirror_num, return ret; } +static int merge_bio(struct extent_io_tree *tree, struct page *page, + unsigned long offset, size_t size, struct bio *bio, + unsigned long bio_flags) +{ + int ret = 0; + if (tree->ops && tree->ops->merge_bio_hook) + ret = tree->ops->merge_bio_hook(page, offset, size, bio, + bio_flags); + BUG_ON(ret < 0); + return ret; + +} + static int submit_extent_page(int rw, struct extent_io_tree *tree, struct page *page, sector_t sector, size_t size, unsigned long offset, @@ -2457,9 +2470,7 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree, sector; if (prev_bio_flags != bio_flags || !contig || - (tree->ops && tree->ops->merge_bio_hook && - tree->ops->merge_bio_hook(page, offset, page_size, bio, - bio_flags)) || + merge_bio(tree, page, offset, page_size, bio, bio_flags) || bio_add_page(bio, page, page_size, offset) < page_size) { ret = submit_one_bio(rw, bio, mirror_num, prev_bio_flags); -- cgit v1.2.3 From 355808c296c6923db6705f43639969a80b16d15d Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Mon, 3 Oct 2011 23:23:14 -0400 Subject: btrfs: ->submit_bio_hook error push-up This pushes failures from the submit_bio_hook callbacks, btrfs_submit_bio_hook and btree_submit_bio_hook into the callers, including callers of submit_one_bio where it catches the failures with BUG_ON. It also pushes up through the ->readpage_io_failed_hook to end_bio_extent_writepage where the error is already caught with BUG_ON. Signed-off-by: Jeff Mahoney --- fs/btrfs/extent_io.c | 37 ++++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 11 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index c342e923ea41..8368baa1f372 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2199,6 +2199,7 @@ int end_extent_writepage(struct page *page, int err, u64 start, u64 end) /* Writeback already completed */ if (ret == 0) return 1; + BUG_ON(ret < 0); } if (!uptodate) { @@ -2351,6 +2352,7 @@ error_handled: if (ret == 0) goto error_handled; } + BUG_ON(ret < 0); } if (uptodate) { @@ -2402,8 +2404,8 @@ btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, return bio; } -static int submit_one_bio(int rw, struct bio *bio, int mirror_num, - unsigned long bio_flags) +static int __must_check submit_one_bio(int rw, struct bio *bio, + int mirror_num, unsigned long bio_flags) { int ret = 0; struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; @@ -2474,6 +2476,7 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree, bio_add_page(bio, page, page_size, offset) < page_size) { ret = submit_one_bio(rw, bio, mirror_num, prev_bio_flags); + BUG_ON(ret < 0); bio = NULL; } else { return 0; @@ -2494,8 +2497,10 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree, if (bio_ret) *bio_ret = bio; - else + else { ret = submit_one_bio(rw, bio, mirror_num, bio_flags); + BUG_ON(ret < 0); + } return ret; } @@ -2707,8 +2712,10 @@ int extent_read_full_page(struct extent_io_tree *tree, struct page *page, ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num, &bio_flags); - if (bio) + if (bio) { ret = submit_one_bio(READ, bio, mirror_num, bio_flags); + BUG_ON(ret < 0); + } return ret; } @@ -3126,10 +3133,14 @@ retry: static void flush_epd_write_bio(struct extent_page_data *epd) { if (epd->bio) { + int rw = WRITE; + int ret; + if (epd->sync_io) - submit_one_bio(WRITE_SYNC, epd->bio, 0, 0); - else - submit_one_bio(WRITE, epd->bio, 0, 0); + rw = WRITE_SYNC; + + ret = submit_one_bio(rw, epd->bio, 0, 0); + BUG_ON(ret < 0); epd->bio = NULL; } } @@ -3245,8 +3256,10 @@ int extent_readpages(struct extent_io_tree *tree, page_cache_release(page); } BUG_ON(!list_empty(pages)); - if (bio) - submit_one_bio(READ, bio, 0, bio_flags); + if (bio) { + int ret = submit_one_bio(READ, bio, 0, bio_flags); + BUG_ON(ret < 0); + } return 0; } @@ -4075,8 +4088,10 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, } } - if (bio) - submit_one_bio(READ, bio, mirror_num, bio_flags); + if (bio) { + err = submit_one_bio(READ, bio, mirror_num, bio_flags); + BUG_ON(err < 0); + } if (ret || wait != WAIT_COMPLETE) return ret; -- cgit v1.2.3 From 143bede527b054a271053f41bfaca2b57baa9408 Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Thu, 1 Mar 2012 14:56:26 +0100 Subject: btrfs: return void in functions without error conditions Signed-off-by: Jeff Mahoney --- fs/btrfs/extent_io.c | 35 ++++++++++++++--------------------- 1 file changed, 14 insertions(+), 21 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 8368baa1f372..65216fabacbb 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -142,6 +142,7 @@ static struct extent_state *alloc_extent_state(gfp_t mask) #endif atomic_set(&state->refs, 1); init_waitqueue_head(&state->wq); + trace_alloc_extent_state(state, mask, _RET_IP_); return state; } @@ -159,6 +160,7 @@ void free_extent_state(struct extent_state *state) list_del(&state->leak_list); spin_unlock_irqrestore(&leak_lock, flags); #endif + trace_free_extent_state(state, _RET_IP_); kmem_cache_free(extent_state_cache, state); } } @@ -617,8 +619,8 @@ search_again: goto again; } -static int wait_on_state(struct extent_io_tree *tree, - struct extent_state *state) +static void wait_on_state(struct extent_io_tree *tree, + struct extent_state *state) __releases(tree->lock) __acquires(tree->lock) { @@ -628,7 +630,6 @@ static int wait_on_state(struct extent_io_tree *tree, schedule(); spin_lock(&tree->lock); finish_wait(&state->wq, &wait); - return 0; } /* @@ -636,7 +637,7 @@ static int wait_on_state(struct extent_io_tree *tree, * The range [start, end] is inclusive. * The tree lock is taken by this function */ -int wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits) +void wait_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits) { struct extent_state *state; struct rb_node *node; @@ -673,7 +674,6 @@ again: } out: spin_unlock(&tree->lock); - return 0; } static void set_state_bits(struct extent_io_tree *tree, @@ -1359,9 +1359,9 @@ out: return found; } -static noinline int __unlock_for_delalloc(struct inode *inode, - struct page *locked_page, - u64 start, u64 end) +static noinline void __unlock_for_delalloc(struct inode *inode, + struct page *locked_page, + u64 start, u64 end) { int ret; struct page *pages[16]; @@ -1371,7 +1371,7 @@ static noinline int __unlock_for_delalloc(struct inode *inode, int i; if (index == locked_page->index && end_index == index) - return 0; + return; while (nr_pages > 0) { ret = find_get_pages_contig(inode->i_mapping, index, @@ -1386,7 +1386,6 @@ static noinline int __unlock_for_delalloc(struct inode *inode, index += ret; cond_resched(); } - return 0; } static noinline int lock_delalloc_pages(struct inode *inode, @@ -1777,39 +1776,34 @@ int test_range_bit(struct extent_io_tree *tree, u64 start, u64 end, * helper function to set a given page up to date if all the * extents in the tree for that page are up to date */ -static int check_page_uptodate(struct extent_io_tree *tree, - struct page *page) +static void check_page_uptodate(struct extent_io_tree *tree, struct page *page) { u64 start = (u64)page->index << PAGE_CACHE_SHIFT; u64 end = start + PAGE_CACHE_SIZE - 1; if (test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL)) SetPageUptodate(page); - return 0; } /* * helper function to unlock a page if all the extents in the tree * for that page are unlocked */ -static int check_page_locked(struct extent_io_tree *tree, - struct page *page) +static void check_page_locked(struct extent_io_tree *tree, struct page *page) { u64 start = (u64)page->index << PAGE_CACHE_SHIFT; u64 end = start + PAGE_CACHE_SIZE - 1; if (!test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL)) unlock_page(page); - return 0; } /* * helper function to end page writeback if all the extents * in the tree for that page are done with writeback */ -static int check_page_writeback(struct extent_io_tree *tree, - struct page *page) +static void check_page_writeback(struct extent_io_tree *tree, + struct page *page) { end_page_writeback(page); - return 0; } /* @@ -3835,7 +3829,7 @@ void free_extent_buffer(struct extent_buffer *eb) WARN_ON(1); } -int clear_extent_buffer_dirty(struct extent_io_tree *tree, +void clear_extent_buffer_dirty(struct extent_io_tree *tree, struct extent_buffer *eb) { unsigned long i; @@ -3867,7 +3861,6 @@ int clear_extent_buffer_dirty(struct extent_io_tree *tree, ClearPageError(page); unlock_page(page); } - return 0; } int set_extent_buffer_dirty(struct extent_io_tree *tree, -- cgit v1.2.3 From d0082371cf086e0ba2bbd0367b2c9920532df24f Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Thu, 1 Mar 2012 14:57:19 +0100 Subject: btrfs: drop gfp_t from lock_extent lock_extent and unlock_extent are always called with GFP_NOFS, drop the argument and use GFP_NOFS consistently. Signed-off-by: Jeff Mahoney --- fs/btrfs/extent_io.c | 41 +++++++++++++++++++---------------------- 1 file changed, 19 insertions(+), 22 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 65216fabacbb..0112c02742f4 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1171,42 +1171,40 @@ static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, * us if waiting is desired. */ int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, - int bits, struct extent_state **cached_state, gfp_t mask) + int bits, struct extent_state **cached_state) { int err; u64 failed_start; while (1) { err = set_extent_bit(tree, start, end, EXTENT_LOCKED | bits, EXTENT_LOCKED, &failed_start, - cached_state, mask); - if (err == -EEXIST && (mask & __GFP_WAIT)) { + cached_state, GFP_NOFS); + if (err == -EEXIST) { wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED); start = failed_start; - } else { + } else break; - } WARN_ON(start > end); } return err; } -int lock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask) +int lock_extent(struct extent_io_tree *tree, u64 start, u64 end) { - return lock_extent_bits(tree, start, end, 0, NULL, mask); + return lock_extent_bits(tree, start, end, 0, NULL); } -int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end, - gfp_t mask) +int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end) { int err; u64 failed_start; err = set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED, - &failed_start, NULL, mask); + &failed_start, NULL, GFP_NOFS); if (err == -EEXIST) { if (failed_start > start) clear_extent_bit(tree, start, failed_start - 1, - EXTENT_LOCKED, 1, 0, NULL, mask); + EXTENT_LOCKED, 1, 0, NULL, GFP_NOFS); return 0; } return 1; @@ -1219,10 +1217,10 @@ int unlock_extent_cached(struct extent_io_tree *tree, u64 start, u64 end, mask); } -int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask) +int unlock_extent(struct extent_io_tree *tree, u64 start, u64 end) { return clear_extent_bit(tree, start, end, EXTENT_LOCKED, 1, 0, NULL, - mask); + GFP_NOFS); } /* @@ -1518,8 +1516,7 @@ again: BUG_ON(ret); /* step three, lock the state bits for the whole range */ - lock_extent_bits(tree, delalloc_start, delalloc_end, - 0, &cached_state, GFP_NOFS); + lock_extent_bits(tree, delalloc_start, delalloc_end, 0, &cached_state); /* then test to make sure it is all still delalloc */ ret = test_range_bit(tree, delalloc_start, delalloc_end, @@ -2557,11 +2554,11 @@ static int __extent_read_full_page(struct extent_io_tree *tree, end = page_end; while (1) { - lock_extent(tree, start, end, GFP_NOFS); + lock_extent(tree, start, end); ordered = btrfs_lookup_ordered_extent(inode, start); if (!ordered) break; - unlock_extent(tree, start, end, GFP_NOFS); + unlock_extent(tree, start, end); btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); } @@ -2598,7 +2595,7 @@ static int __extent_read_full_page(struct extent_io_tree *tree, end - cur + 1, 0); if (IS_ERR_OR_NULL(em)) { SetPageError(page); - unlock_extent(tree, cur, end, GFP_NOFS); + unlock_extent(tree, cur, end); break; } extent_offset = cur - em->start; @@ -2650,7 +2647,7 @@ static int __extent_read_full_page(struct extent_io_tree *tree, if (test_range_bit(tree, cur, cur_end, EXTENT_UPTODATE, 1, NULL)) { check_page_uptodate(tree, page); - unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); + unlock_extent(tree, cur, cur + iosize - 1); cur = cur + iosize; pg_offset += iosize; continue; @@ -2660,7 +2657,7 @@ static int __extent_read_full_page(struct extent_io_tree *tree, */ if (block_start == EXTENT_MAP_INLINE) { SetPageError(page); - unlock_extent(tree, cur, cur + iosize - 1, GFP_NOFS); + unlock_extent(tree, cur, cur + iosize - 1); cur = cur + iosize; pg_offset += iosize; continue; @@ -3274,7 +3271,7 @@ int extent_invalidatepage(struct extent_io_tree *tree, if (start > end) return 0; - lock_extent_bits(tree, start, end, 0, &cached_state, GFP_NOFS); + lock_extent_bits(tree, start, end, 0, &cached_state); wait_on_page_writeback(page); clear_extent_bit(tree, start, end, EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC | @@ -3488,7 +3485,7 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, } lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0, - &cached_state, GFP_NOFS); + &cached_state); em = get_extent_skip_holes(inode, start, last_for_get_extent, get_extent); -- cgit v1.2.3 From 3fbe5c02ae5a59053d779392b9a12aa8f6d6198e Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Thu, 1 Mar 2012 14:57:19 +0100 Subject: btrfs: split extent_state ops set_extent_bit can do exclusive locking but only when called by lock_extent*, Drop the exclusive bits argument except when called by lock_extent. Signed-off-by: Jeff Mahoney --- fs/btrfs/extent_io.c | 36 +++++++++++++++++++++++------------- 1 file changed, 23 insertions(+), 13 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 0112c02742f4..ffa7cc3370c7 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -721,9 +721,10 @@ static void uncache_state(struct extent_state **cached_ptr) * [start, end] is inclusive This takes the tree lock. */ -int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, - int bits, int exclusive_bits, u64 *failed_start, - struct extent_state **cached_state, gfp_t mask) +static int __must_check +__set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, + int bits, int exclusive_bits, u64 *failed_start, + struct extent_state **cached_state, gfp_t mask) { struct extent_state *state; struct extent_state *prealloc = NULL; @@ -917,6 +918,15 @@ search_again: goto again; } +int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits, + u64 *failed_start, struct extent_state **cached_state, + gfp_t mask) +{ + return __set_extent_bit(tree, start, end, bits, 0, failed_start, + cached_state, mask); +} + + /** * convert_extent - convert all bits in a given range from one bit to another * @tree: the io tree to search @@ -1111,14 +1121,14 @@ search_again: int set_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask) { - return set_extent_bit(tree, start, end, EXTENT_DIRTY, 0, NULL, + return set_extent_bit(tree, start, end, EXTENT_DIRTY, NULL, NULL, mask); } int set_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int bits, gfp_t mask) { - return set_extent_bit(tree, start, end, bits, 0, NULL, + return set_extent_bit(tree, start, end, bits, NULL, NULL, mask); } @@ -1133,7 +1143,7 @@ int set_extent_delalloc(struct extent_io_tree *tree, u64 start, u64 end, { return set_extent_bit(tree, start, end, EXTENT_DELALLOC | EXTENT_UPTODATE, - 0, NULL, cached_state, mask); + NULL, cached_state, mask); } int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end, @@ -1147,7 +1157,7 @@ int clear_extent_dirty(struct extent_io_tree *tree, u64 start, u64 end, int set_extent_new(struct extent_io_tree *tree, u64 start, u64 end, gfp_t mask) { - return set_extent_bit(tree, start, end, EXTENT_NEW, 0, NULL, + return set_extent_bit(tree, start, end, EXTENT_NEW, NULL, NULL, mask); } @@ -1155,7 +1165,7 @@ int set_extent_uptodate(struct extent_io_tree *tree, u64 start, u64 end, struct extent_state **cached_state, gfp_t mask) { return set_extent_bit(tree, start, end, EXTENT_UPTODATE, 0, - NULL, cached_state, mask); + cached_state, mask); } static int clear_extent_uptodate(struct extent_io_tree *tree, u64 start, @@ -1176,9 +1186,9 @@ int lock_extent_bits(struct extent_io_tree *tree, u64 start, u64 end, int err; u64 failed_start; while (1) { - err = set_extent_bit(tree, start, end, EXTENT_LOCKED | bits, - EXTENT_LOCKED, &failed_start, - cached_state, GFP_NOFS); + err = __set_extent_bit(tree, start, end, EXTENT_LOCKED | bits, + EXTENT_LOCKED, &failed_start, + cached_state, GFP_NOFS); if (err == -EEXIST) { wait_extent_bit(tree, failed_start, end, EXTENT_LOCKED); start = failed_start; @@ -1199,8 +1209,8 @@ int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end) int err; u64 failed_start; - err = set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED, - &failed_start, NULL, GFP_NOFS); + err = __set_extent_bit(tree, start, end, EXTENT_LOCKED, EXTENT_LOCKED, + &failed_start, NULL, GFP_NOFS); if (err == -EEXIST) { if (failed_start > start) clear_extent_bit(tree, start, failed_start - 1, -- cgit v1.2.3 From 79787eaab46121d4713ed03c8fc63b9ec3eaec76 Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Mon, 12 Mar 2012 16:03:00 +0100 Subject: btrfs: replace many BUG_ONs with proper error handling btrfs currently handles most errors with BUG_ON. This patch is a work-in- progress but aims to handle most errors other than internal logic errors and ENOMEM more gracefully. This iteration prevents most crashes but can run into lockups with the page lock on occasion when the timing "works out." Signed-off-by: Jeff Mahoney --- fs/btrfs/extent_io.c | 40 ++++++++++++++++++++++------------------ 1 file changed, 22 insertions(+), 18 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index ffa7cc3370c7..4c3ce7a0a7a4 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1244,7 +1244,7 @@ static int set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end) while (index <= end_index) { page = find_get_page(tree->mapping, index); - BUG_ON(!page); + BUG_ON(!page); /* Pages should be in the extent_io_tree */ set_page_writeback(page); page_cache_release(page); index++; @@ -1523,7 +1523,7 @@ again: goto out_failed; } } - BUG_ON(ret); + BUG_ON(ret); /* Only valid values are 0 and -EAGAIN */ /* step three, lock the state bits for the whole range */ lock_extent_bits(tree, delalloc_start, delalloc_end, 0, &cached_state); @@ -2200,7 +2200,6 @@ int end_extent_writepage(struct page *page, int err, u64 start, u64 end) /* Writeback already completed */ if (ret == 0) return 1; - BUG_ON(ret < 0); } if (!uptodate) { @@ -2353,7 +2352,6 @@ error_handled: if (ret == 0) goto error_handled; } - BUG_ON(ret < 0); } if (uptodate) { @@ -2405,6 +2403,10 @@ btrfs_bio_alloc(struct block_device *bdev, u64 first_sector, int nr_vecs, return bio; } +/* + * Since writes are async, they will only return -ENOMEM. + * Reads can return the full range of I/O error conditions. + */ static int __must_check submit_one_bio(int rw, struct bio *bio, int mirror_num, unsigned long bio_flags) { @@ -2477,7 +2479,8 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree, bio_add_page(bio, page, page_size, offset) < page_size) { ret = submit_one_bio(rw, bio, mirror_num, prev_bio_flags); - BUG_ON(ret < 0); + if (ret < 0) + return ret; bio = NULL; } else { return 0; @@ -2498,10 +2501,8 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree, if (bio_ret) *bio_ret = bio; - else { + else ret = submit_one_bio(rw, bio, mirror_num, bio_flags); - BUG_ON(ret < 0); - } return ret; } @@ -2525,6 +2526,7 @@ static void set_page_extent_head(struct page *page, unsigned long len) * basic readpage implementation. Locked extent state structs are inserted * into the tree that are removed when the IO is done (by the end_io * handlers) + * XXX JDM: This needs looking at to ensure proper page locking */ static int __extent_read_full_page(struct extent_io_tree *tree, struct page *page, @@ -2687,6 +2689,7 @@ static int __extent_read_full_page(struct extent_io_tree *tree, end_bio_extent_readpage, mirror_num, *bio_flags, this_bio_flag); + BUG_ON(ret == -ENOMEM); nr++; *bio_flags = this_bio_flag; } @@ -2713,10 +2716,8 @@ int extent_read_full_page(struct extent_io_tree *tree, struct page *page, ret = __extent_read_full_page(tree, page, get_extent, &bio, mirror_num, &bio_flags); - if (bio) { + if (bio) ret = submit_one_bio(READ, bio, mirror_num, bio_flags); - BUG_ON(ret < 0); - } return ret; } @@ -2830,7 +2831,11 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc, delalloc_end, &page_started, &nr_written); - BUG_ON(ret); + /* File system has been set read-only */ + if (ret) { + SetPageError(page); + goto done; + } /* * delalloc_end is already one less than the total * length, so we don't subtract one from @@ -3141,7 +3146,7 @@ static void flush_epd_write_bio(struct extent_page_data *epd) rw = WRITE_SYNC; ret = submit_one_bio(rw, epd->bio, 0, 0); - BUG_ON(ret < 0); + BUG_ON(ret < 0); /* -ENOMEM */ epd->bio = NULL; } } @@ -3257,10 +3262,8 @@ int extent_readpages(struct extent_io_tree *tree, page_cache_release(page); } BUG_ON(!list_empty(pages)); - if (bio) { - int ret = submit_one_bio(READ, bio, 0, bio_flags); - BUG_ON(ret < 0); - } + if (bio) + return submit_one_bio(READ, bio, 0, bio_flags); return 0; } @@ -4090,7 +4093,8 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, if (bio) { err = submit_one_bio(READ, bio, mirror_num, bio_flags); - BUG_ON(err < 0); + if (err) + return err; } if (ret || wait != WAIT_COMPLETE) -- cgit v1.2.3 From 727011e07cbdf87772fcc1999cccd15cc915eb62 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Fri, 6 Aug 2010 13:21:20 -0400 Subject: Btrfs: allow metadata blocks larger than the page size A few years ago the btrfs code to support blocks lager than the page size was disabled to fix a few corner cases in the page cache handling. This fixes the code to properly support large metadata blocks again. Since current kernels will crash early and often with larger metadata blocks, this adds an incompat bit so that older kernels can't mount it. This also does away with different blocksizes for nodes and leaves. You get a single block size for all tree blocks. Signed-off-by: Chris Mason --- fs/btrfs/extent_io.c | 144 ++++++++++++++++++++++----------------------------- 1 file changed, 63 insertions(+), 81 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index a55fbe6252de..c6c9ce463c86 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3548,26 +3548,7 @@ out: inline struct page *extent_buffer_page(struct extent_buffer *eb, unsigned long i) { - struct page *p; - struct address_space *mapping; - - if (i == 0) - return eb->first_page; - i += eb->start >> PAGE_CACHE_SHIFT; - mapping = eb->first_page->mapping; - if (!mapping) - return NULL; - - /* - * extent_buffer_page is only called after pinning the page - * by increasing the reference count. So we know the page must - * be in the radix tree. - */ - rcu_read_lock(); - p = radix_tree_lookup(&mapping->page_tree, i); - rcu_read_unlock(); - - return p; + return eb->pages[i]; } inline unsigned long num_extent_pages(u64 start, u64 len) @@ -3576,6 +3557,19 @@ inline unsigned long num_extent_pages(u64 start, u64 len) (start >> PAGE_CACHE_SHIFT); } +static void __free_extent_buffer(struct extent_buffer *eb) +{ +#if LEAK_DEBUG + unsigned long flags; + spin_lock_irqsave(&leak_lock, flags); + list_del(&eb->leak_list); + spin_unlock_irqrestore(&leak_lock, flags); +#endif + if (eb->pages && eb->pages != eb->inline_pages) + kfree(eb->pages); + kmem_cache_free(extent_buffer_cache, eb); +} + static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree, u64 start, unsigned long len, @@ -3608,21 +3602,25 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree, spin_unlock_irqrestore(&leak_lock, flags); #endif atomic_set(&eb->refs, 1); + atomic_set(&eb->pages_reading, 0); + + if (len > MAX_INLINE_EXTENT_BUFFER_SIZE) { + struct page **pages; + int num_pages = (len + PAGE_CACHE_SIZE - 1) >> + PAGE_CACHE_SHIFT; + pages = kzalloc(num_pages, mask); + if (!pages) { + __free_extent_buffer(eb); + return NULL; + } + eb->pages = pages; + } else { + eb->pages = eb->inline_pages; + } return eb; } -static void __free_extent_buffer(struct extent_buffer *eb) -{ -#if LEAK_DEBUG - unsigned long flags; - spin_lock_irqsave(&leak_lock, flags); - list_del(&eb->leak_list); - spin_unlock_irqrestore(&leak_lock, flags); -#endif - kmem_cache_free(extent_buffer_cache, eb); -} - /* * Helper for releasing extent buffer page. */ @@ -3632,9 +3630,6 @@ static void btrfs_release_extent_buffer_page(struct extent_buffer *eb, unsigned long index; struct page *page; - if (!eb->first_page) - return; - index = num_extent_pages(eb->start, eb->len); if (start_idx >= index) return; @@ -3657,8 +3652,7 @@ static inline void btrfs_release_extent_buffer(struct extent_buffer *eb) } struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, - u64 start, unsigned long len, - struct page *page0) + u64 start, unsigned long len) { unsigned long num_pages = num_extent_pages(start, len); unsigned long i; @@ -3674,7 +3668,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT); if (eb && atomic_inc_not_zero(&eb->refs)) { rcu_read_unlock(); - mark_page_accessed(eb->first_page); + mark_page_accessed(eb->pages[0]); return eb; } rcu_read_unlock(); @@ -3683,32 +3677,14 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, if (!eb) return NULL; - if (page0) { - eb->first_page = page0; - i = 1; - index++; - page_cache_get(page0); - mark_page_accessed(page0); - set_page_extent_mapped(page0); - set_page_extent_head(page0, len); - uptodate = PageUptodate(page0); - } else { - i = 0; - } - for (; i < num_pages; i++, index++) { + for (i = 0; i < num_pages; i++, index++) { p = find_or_create_page(mapping, index, GFP_NOFS); if (!p) { WARN_ON(1); goto free_eb; } - set_page_extent_mapped(p); mark_page_accessed(p); - if (i == 0) { - eb->first_page = p; - set_page_extent_head(p, len); - } else { - set_page_private(p, EXTENT_PAGE_PRIVATE); - } + eb->pages[i] = p; if (!PageUptodate(p)) uptodate = 0; @@ -3716,8 +3692,6 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, * see below about how we avoid a nasty race with release page * and why we unlock later */ - if (i != 0) - unlock_page(p); } if (uptodate) set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); @@ -3751,15 +3725,23 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, * after the extent buffer is in the radix tree so * it doesn't get lost */ - set_page_extent_mapped(eb->first_page); - set_page_extent_head(eb->first_page, eb->len); - if (!page0) - unlock_page(eb->first_page); + set_page_extent_mapped(eb->pages[0]); + set_page_extent_head(eb->pages[0], eb->len); + SetPageChecked(eb->pages[0]); + for (i = 1; i < num_pages; i++) { + p = extent_buffer_page(eb, i); + set_page_extent_mapped(p); + ClearPageChecked(p); + unlock_page(p); + } + unlock_page(eb->pages[0]); return eb; free_eb: - if (eb->first_page && !page0) - unlock_page(eb->first_page); + for (i = 0; i < num_pages; i++) { + if (eb->pages[i]) + unlock_page(eb->pages[i]); + } if (!atomic_dec_and_test(&eb->refs)) return exists; @@ -3776,7 +3758,7 @@ struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree, eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT); if (eb && atomic_inc_not_zero(&eb->refs)) { rcu_read_unlock(); - mark_page_accessed(eb->first_page); + mark_page_accessed(eb->pages[0]); return eb; } rcu_read_unlock(); @@ -3981,8 +3963,8 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, int ret = 0; int locked_pages = 0; int all_uptodate = 1; - int inc_all_pages = 0; unsigned long num_pages; + unsigned long num_reads = 0; struct bio *bio = NULL; unsigned long bio_flags = 0; @@ -4014,8 +3996,10 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, lock_page(page); } locked_pages++; - if (!PageUptodate(page)) + if (!PageUptodate(page)) { + num_reads++; all_uptodate = 0; + } } if (all_uptodate) { if (start_i == 0) @@ -4023,20 +4007,13 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, goto unlock_exit; } + atomic_set(&eb->pages_reading, num_reads); for (i = start_i; i < num_pages; i++) { page = extent_buffer_page(eb, i); - - WARN_ON(!PagePrivate(page)); - set_page_extent_mapped(page); if (i == 0) set_page_extent_head(page, eb->len); - - if (inc_all_pages) - page_cache_get(page); if (!PageUptodate(page)) { - if (start_i == 0) - inc_all_pages = 1; ClearPageError(page); err = __extent_read_full_page(tree, page, get_extent, &bio, @@ -4304,15 +4281,20 @@ static void copy_pages(struct page *dst_page, struct page *src_page, { char *dst_kaddr = page_address(dst_page); char *src_kaddr; + int must_memmove = 0; if (dst_page != src_page) { src_kaddr = page_address(src_page); } else { src_kaddr = dst_kaddr; - BUG_ON(areas_overlap(src_off, dst_off, len)); + if (areas_overlap(src_off, dst_off, len)) + must_memmove = 1; } - memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); + if (must_memmove) + memmove(dst_kaddr + dst_off, src_kaddr + src_off, len); + else + memcpy(dst_kaddr + dst_off, src_kaddr + src_off, len); } void memcpy_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, @@ -4382,7 +4364,7 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, "len %lu len %lu\n", dst_offset, len, dst->len); BUG_ON(1); } - if (!areas_overlap(src_offset, dst_offset, len)) { + if (dst_offset < src_offset) { memcpy_extent_buffer(dst, dst_offset, src_offset, len); return; } @@ -4429,7 +4411,8 @@ int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page) return ret; } - if (test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) { + if (atomic_read(&eb->refs) > 1 || + test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) { ret = 0; goto out; } @@ -4442,7 +4425,6 @@ int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page) ret = 0; goto out; } - radix_tree_delete(&tree->buffer, start >> PAGE_CACHE_SHIFT); out: spin_unlock(&tree->buffer_lock); -- cgit v1.2.3 From 4f2de97acee6532b36dd6e995b858343771ad126 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Wed, 7 Mar 2012 16:20:05 -0500 Subject: Btrfs: set page->private to the eb We spend a lot of time looking up extent buffers from pages when we could just store the pointer to the eb the page is associated with in page->private. This patch does just that, and it makes things a little simpler and reduces a bit of CPU overhead involved with doing metadata IO. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/extent_io.c | 92 ++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 67 insertions(+), 25 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index c6c9ce463c86..0381b6007ae4 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2473,19 +2473,24 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree, return ret; } -void set_page_extent_mapped(struct page *page) +void attach_extent_buffer_page(struct extent_buffer *eb, struct page *page) { if (!PagePrivate(page)) { SetPagePrivate(page); page_cache_get(page); - set_page_private(page, EXTENT_PAGE_PRIVATE); + set_page_private(page, (unsigned long)eb); + } else { + WARN_ON(page->private != (unsigned long)eb); } } -static void set_page_extent_head(struct page *page, unsigned long len) +void set_page_extent_mapped(struct page *page) { - WARN_ON(!PagePrivate(page)); - set_page_private(page, EXTENT_PAGE_PRIVATE_FIRST_PAGE | len << 2); + if (!PagePrivate(page)) { + SetPagePrivate(page); + page_cache_get(page); + set_page_private(page, EXTENT_PAGE_PRIVATE); + } } /* @@ -3585,6 +3590,7 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree, return NULL; eb->start = start; eb->len = len; + eb->tree = tree; rwlock_init(&eb->lock); atomic_set(&eb->write_locks, 0); atomic_set(&eb->read_locks, 0); @@ -3637,8 +3643,31 @@ static void btrfs_release_extent_buffer_page(struct extent_buffer *eb, do { index--; page = extent_buffer_page(eb, index); - if (page) + if (page) { + spin_lock(&page->mapping->private_lock); + /* + * We do this since we'll remove the pages after we've + * removed the eb from the radix tree, so we could race + * and have this page now attached to the new eb. So + * only clear page_private if it's still connected to + * this eb. + */ + if (PagePrivate(page) && + page->private == (unsigned long)eb) { + /* + * We need to make sure we haven't be attached + * to a new eb. + */ + ClearPagePrivate(page); + set_page_private(page, 0); + /* One for the page private */ + page_cache_release(page); + } + spin_unlock(&page->mapping->private_lock); + + /* One for when we alloced the page */ page_cache_release(page); + } } while (index != start_idx); } @@ -3683,6 +3712,32 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, WARN_ON(1); goto free_eb; } + + spin_lock(&mapping->private_lock); + if (PagePrivate(p)) { + /* + * We could have already allocated an eb for this page + * and attached one so lets see if we can get a ref on + * the existing eb, and if we can we know it's good and + * we can just return that one, else we know we can just + * overwrite page->private. + */ + exists = (struct extent_buffer *)p->private; + if (atomic_inc_not_zero(&exists->refs)) { + spin_unlock(&mapping->private_lock); + unlock_page(p); + goto free_eb; + } + + /* + * Do this so attach doesn't complain and we need to + * drop the ref the old guy had. + */ + ClearPagePrivate(p); + page_cache_release(p); + } + attach_extent_buffer_page(eb, p); + spin_unlock(&mapping->private_lock); mark_page_accessed(p); eb->pages[i] = p; if (!PageUptodate(p)) @@ -3705,7 +3760,6 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, if (ret == -EEXIST) { exists = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT); - /* add one reference for the caller */ atomic_inc(&exists->refs); spin_unlock(&tree->buffer_lock); radix_tree_preload_end(); @@ -3725,12 +3779,9 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, * after the extent buffer is in the radix tree so * it doesn't get lost */ - set_page_extent_mapped(eb->pages[0]); - set_page_extent_head(eb->pages[0], eb->len); SetPageChecked(eb->pages[0]); for (i = 1; i < num_pages; i++) { p = extent_buffer_page(eb, i); - set_page_extent_mapped(p); ClearPageChecked(p); unlock_page(p); } @@ -3794,10 +3845,6 @@ int clear_extent_buffer_dirty(struct extent_io_tree *tree, lock_page(page); WARN_ON(!PagePrivate(page)); - set_page_extent_mapped(page); - if (i == 0) - set_page_extent_head(page, eb->len); - clear_page_dirty_for_io(page); spin_lock_irq(&page->mapping->tree_lock); if (!PageDirty(page)) { @@ -4010,9 +4057,6 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, atomic_set(&eb->pages_reading, num_reads); for (i = start_i; i < num_pages; i++) { page = extent_buffer_page(eb, i); - set_page_extent_mapped(page); - if (i == 0) - set_page_extent_head(page, eb->len); if (!PageUptodate(page)) { ClearPageError(page); err = __extent_read_full_page(tree, page, @@ -4395,22 +4439,19 @@ static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head) struct extent_buffer *eb = container_of(head, struct extent_buffer, rcu_head); - btrfs_release_extent_buffer(eb); + __free_extent_buffer(eb); } int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page) { u64 start = page_offset(page); - struct extent_buffer *eb; + struct extent_buffer *eb = (struct extent_buffer *)page->private; int ret = 1; - spin_lock(&tree->buffer_lock); - eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT); - if (!eb) { - spin_unlock(&tree->buffer_lock); - return ret; - } + if (!PagePrivate(page) || !eb) + return 1; + spin_lock(&tree->buffer_lock); if (atomic_read(&eb->refs) > 1 || test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) { ret = 0; @@ -4426,6 +4467,7 @@ int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page) goto out; } radix_tree_delete(&tree->buffer, start >> PAGE_CACHE_SHIFT); + btrfs_release_extent_buffer_page(eb, 0); out: spin_unlock(&tree->buffer_lock); -- cgit v1.2.3 From 115391d2315239164e400a8259b26392afccf3bd Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 9 Mar 2012 09:51:43 -0500 Subject: Btrfs: only use the existing eb if it's count isn't 0 We can run into a problem where we find an eb for our existing page already on the radix tree but it has a ref count of 0. It hasn't yet been removed by RCU yet so this can cause issues where we will use the EB after free. So do atomic_inc_not_zero on the exists->refs and if it is zero just do synchronize_rcu() and try again. We won't have to worry about new allocators coming in since they will block on the page lock at this point. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/extent_io.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 0381b6007ae4..0f74262911be 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3750,7 +3750,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, } if (uptodate) set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); - +again: ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM); if (ret) goto free_eb; @@ -3760,7 +3760,13 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, if (ret == -EEXIST) { exists = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT); - atomic_inc(&exists->refs); + if (!atomic_inc_not_zero(&exists->refs)) { + spin_unlock(&tree->buffer_lock); + radix_tree_preload_end(); + synchronize_rcu(); + exists = NULL; + goto again; + } spin_unlock(&tree->buffer_lock); radix_tree_preload_end(); goto free_eb; -- cgit v1.2.3 From 3083ee2e18b701122a3b841db83448543a87a583 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 9 Mar 2012 16:01:49 -0500 Subject: Btrfs: introduce free_extent_buffer_stale Because btrfs cow's we can end up with extent buffers that are no longer necessary just sitting around in memory. So instead of evicting these pages, we could end up evicting things we actually care about. Thus we have free_extent_buffer_stale for use when we are freeing tree blocks. This will make it so that the ref for the eb being in the radix tree is dropped as soon as possible and then is freed when the refcount hits 0 instead of waiting to be released by releasepage. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/extent_io.c | 205 ++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 171 insertions(+), 34 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 0f74262911be..0ce14369920c 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3607,6 +3607,7 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree, list_add(&eb->leak_list, &buffers); spin_unlock_irqrestore(&leak_lock, flags); #endif + spin_lock_init(&eb->refs_lock); atomic_set(&eb->refs, 1); atomic_set(&eb->pages_reading, 0); @@ -3654,6 +3655,8 @@ static void btrfs_release_extent_buffer_page(struct extent_buffer *eb, */ if (PagePrivate(page) && page->private == (unsigned long)eb) { + BUG_ON(PageDirty(page)); + BUG_ON(PageWriteback(page)); /* * We need to make sure we haven't be attached * to a new eb. @@ -3763,7 +3766,6 @@ again: if (!atomic_inc_not_zero(&exists->refs)) { spin_unlock(&tree->buffer_lock); radix_tree_preload_end(); - synchronize_rcu(); exists = NULL; goto again; } @@ -3772,7 +3774,10 @@ again: goto free_eb; } /* add one reference for the tree */ + spin_lock(&eb->refs_lock); atomic_inc(&eb->refs); + set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags); + spin_unlock(&eb->refs_lock); spin_unlock(&tree->buffer_lock); radix_tree_preload_end(); @@ -3823,15 +3828,143 @@ struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree, return NULL; } +static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head) +{ + struct extent_buffer *eb = + container_of(head, struct extent_buffer, rcu_head); + + __free_extent_buffer(eb); +} + +static int extent_buffer_under_io(struct extent_buffer *eb, + struct page *locked_page) +{ + unsigned long num_pages, i; + + num_pages = num_extent_pages(eb->start, eb->len); + for (i = 0; i < num_pages; i++) { + struct page *page = eb->pages[i]; + int need_unlock = 0; + + if (!page) + continue; + + if (page != locked_page) { + if (!trylock_page(page)) + return 1; + need_unlock = 1; + } + + if (PageDirty(page) || PageWriteback(page)) { + if (need_unlock) + unlock_page(page); + return 1; + } + if (need_unlock) + unlock_page(page); + } + + return 0; +} + +/* Expects to have eb->eb_lock already held */ +static void release_extent_buffer(struct extent_buffer *eb, gfp_t mask) +{ + WARN_ON(atomic_read(&eb->refs) == 0); + if (atomic_dec_and_test(&eb->refs)) { + struct extent_io_tree *tree = eb->tree; + int ret; + + spin_unlock(&eb->refs_lock); + + might_sleep_if(mask & __GFP_WAIT); + ret = clear_extent_bit(tree, eb->start, + eb->start + eb->len - 1, -1, 0, 0, + NULL, mask); + if (ret < 0) { + unsigned long num_pages, i; + + num_pages = num_extent_pages(eb->start, eb->len); + /* + * We failed to clear the state bits which likely means + * ENOMEM, so just re-up the eb ref and continue, we + * will get freed later on via releasepage or something + * else and will be ok. + */ + spin_lock(&eb->tree->mapping->private_lock); + spin_lock(&eb->refs_lock); + set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags); + atomic_inc(&eb->refs); + + /* + * We may have started to reclaim the pages for a newly + * allocated eb, make sure we own all of them again. + */ + for (i = 0; i < num_pages; i++) { + struct page *page = eb->pages[i]; + + if (!page) { + WARN_ON(1); + continue; + } + + BUG_ON(!PagePrivate(page)); + if (page->private != (unsigned long)eb) { + ClearPagePrivate(page); + page_cache_release(page); + attach_extent_buffer_page(eb, page); + } + } + spin_unlock(&eb->refs_lock); + spin_unlock(&eb->tree->mapping->private_lock); + return; + } + + spin_lock(&tree->buffer_lock); + radix_tree_delete(&tree->buffer, + eb->start >> PAGE_CACHE_SHIFT); + spin_unlock(&tree->buffer_lock); + + /* Should be safe to release our pages at this point */ + btrfs_release_extent_buffer_page(eb, 0); + + call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu); + return; + } + spin_unlock(&eb->refs_lock); +} + void free_extent_buffer(struct extent_buffer *eb) { if (!eb) return; - if (!atomic_dec_and_test(&eb->refs)) + spin_lock(&eb->refs_lock); + if (atomic_read(&eb->refs) == 2 && + test_bit(EXTENT_BUFFER_STALE, &eb->bflags) && + !extent_buffer_under_io(eb, NULL) && + test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) + atomic_dec(&eb->refs); + + /* + * I know this is terrible, but it's temporary until we stop tracking + * the uptodate bits and such for the extent buffers. + */ + release_extent_buffer(eb, GFP_ATOMIC); +} + +void free_extent_buffer_stale(struct extent_buffer *eb) +{ + if (!eb) return; - WARN_ON(1); + spin_lock(&eb->refs_lock); + set_bit(EXTENT_BUFFER_STALE, &eb->bflags); + + if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb, NULL) && + test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) + atomic_dec(&eb->refs); + release_extent_buffer(eb, GFP_NOFS); } int clear_extent_buffer_dirty(struct extent_io_tree *tree, @@ -3874,6 +4007,7 @@ int set_extent_buffer_dirty(struct extent_io_tree *tree, was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags); num_pages = num_extent_pages(eb->start, eb->len); + WARN_ON(atomic_read(&eb->refs) == 0); for (i = 0; i < num_pages; i++) __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); return was_dirty; @@ -4440,45 +4574,48 @@ void memmove_extent_buffer(struct extent_buffer *dst, unsigned long dst_offset, } } -static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head) -{ - struct extent_buffer *eb = - container_of(head, struct extent_buffer, rcu_head); - - __free_extent_buffer(eb); -} - -int try_release_extent_buffer(struct extent_io_tree *tree, struct page *page) +int try_release_extent_buffer(struct page *page, gfp_t mask) { - u64 start = page_offset(page); - struct extent_buffer *eb = (struct extent_buffer *)page->private; - int ret = 1; + struct extent_buffer *eb; - if (!PagePrivate(page) || !eb) + /* + * We need to make sure noboody is attaching this page to an eb right + * now. + */ + spin_lock(&page->mapping->private_lock); + if (!PagePrivate(page)) { + spin_unlock(&page->mapping->private_lock); return 1; + } - spin_lock(&tree->buffer_lock); - if (atomic_read(&eb->refs) > 1 || - test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) { - ret = 0; - goto out; + eb = (struct extent_buffer *)page->private; + BUG_ON(!eb); + + /* + * This is a little awful but should be ok, we need to make sure that + * the eb doesn't disappear out from under us while we're looking at + * this page. + */ + spin_lock(&eb->refs_lock); + if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb, page)) { + spin_unlock(&eb->refs_lock); + spin_unlock(&page->mapping->private_lock); + return 0; } + spin_unlock(&page->mapping->private_lock); + + if ((mask & GFP_NOFS) == GFP_NOFS) + mask = GFP_NOFS; /* - * set @eb->refs to 0 if it is already 1, and then release the @eb. - * Or go back. + * If tree ref isn't set then we know the ref on this eb is a real ref, + * so just return, this page will likely be freed soon anyway. */ - if (atomic_cmpxchg(&eb->refs, 1, 0) != 1) { - ret = 0; - goto out; + if (!test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) { + spin_unlock(&eb->refs_lock); + return 0; } - radix_tree_delete(&tree->buffer, start >> PAGE_CACHE_SHIFT); - btrfs_release_extent_buffer_page(eb, 0); -out: - spin_unlock(&tree->buffer_lock); + release_extent_buffer(eb, mask); - /* at this point we can safely release the extent buffer */ - if (atomic_read(&eb->refs) == 0) - call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu); - return ret; + return 1; } -- cgit v1.2.3 From 5df4235ea15bd39f441ef334d8329b3d46b2cc57 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Thu, 15 Mar 2012 18:24:42 -0400 Subject: Btrfs: introduce mark_extent_buffer_accessed Because an eb can have multiple pages we need to make sure that all pages within the eb are markes as accessed, since releasepage can be called against any page in the eb. This will keep us from possibly evicting hot eb's when we're doing larger than pagesize eb's. Thanks, Signed-off-by: Josef Bacik --- fs/btrfs/extent_io.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 0ce14369920c..4a97d8fd958d 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3683,6 +3683,17 @@ static inline void btrfs_release_extent_buffer(struct extent_buffer *eb) __free_extent_buffer(eb); } +static void mark_extent_buffer_accessed(struct extent_buffer *eb) +{ + unsigned long num_pages, i; + + num_pages = num_extent_pages(eb->start, eb->len); + for (i = 0; i < num_pages; i++) { + struct page *p = extent_buffer_page(eb, i); + mark_page_accessed(p); + } +} + struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, u64 start, unsigned long len) { @@ -3700,7 +3711,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT); if (eb && atomic_inc_not_zero(&eb->refs)) { rcu_read_unlock(); - mark_page_accessed(eb->pages[0]); + mark_extent_buffer_accessed(eb); return eb; } rcu_read_unlock(); @@ -3729,6 +3740,7 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, if (atomic_inc_not_zero(&exists->refs)) { spin_unlock(&mapping->private_lock); unlock_page(p); + mark_extent_buffer_accessed(exists); goto free_eb; } @@ -3771,6 +3783,7 @@ again: } spin_unlock(&tree->buffer_lock); radix_tree_preload_end(); + mark_extent_buffer_accessed(exists); goto free_eb; } /* add one reference for the tree */ @@ -3820,7 +3833,7 @@ struct extent_buffer *find_extent_buffer(struct extent_io_tree *tree, eb = radix_tree_lookup(&tree->buffer, start >> PAGE_CACHE_SHIFT); if (eb && atomic_inc_not_zero(&eb->refs)) { rcu_read_unlock(); - mark_page_accessed(eb->pages[0]); + mark_extent_buffer_accessed(eb); return eb; } rcu_read_unlock(); -- cgit v1.2.3 From 0b32f4bbb423f02acee6d43cd442f5f0775db7e0 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Tue, 13 Mar 2012 09:38:00 -0400 Subject: Btrfs: ensure an entire eb is written at once This patch simplifies how we track our extent buffers. Previously we could exit writepages with only having written half of an extent buffer, which meant we had to track the state of the pages and the state of the extent buffers differently. Now we only read in entire extent buffers and write out entire extent buffers, this allows us to simply set bits in our bflags to indicate the state of the eb and we no longer have to do things like track uptodate with our iotree. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/extent_io.c | 497 +++++++++++++++++++++++++++++++++++---------------- 1 file changed, 342 insertions(+), 155 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 4a97d8fd958d..c1b898d590d7 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -19,6 +19,7 @@ #include "btrfs_inode.h" #include "volumes.h" #include "check-integrity.h" +#include "locking.h" static struct kmem_cache *extent_state_cache; static struct kmem_cache *extent_buffer_cache; @@ -53,6 +54,8 @@ struct extent_page_data { unsigned int sync_io:1; }; +static noinline void flush_write_bio(void *data); + int __init extent_io_init(void) { extent_state_cache = kmem_cache_create("extent_state", @@ -2337,7 +2340,7 @@ error_handled: } } - if (uptodate) { + if (uptodate && tree->track_uptodate) { set_extent_uptodate(tree, start, end, &cached, GFP_ATOMIC); } @@ -2973,6 +2976,275 @@ done_unlocked: return 0; } +static int eb_wait(void *word) +{ + io_schedule(); + return 0; +} + +static void wait_on_extent_buffer_writeback(struct extent_buffer *eb) +{ + wait_on_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK, eb_wait, + TASK_UNINTERRUPTIBLE); +} + +static int lock_extent_buffer_for_io(struct extent_buffer *eb, + struct btrfs_fs_info *fs_info, + struct extent_page_data *epd) +{ + unsigned long i, num_pages; + int flush = 0; + int ret = 0; + + if (!btrfs_try_tree_write_lock(eb)) { + flush = 1; + flush_write_bio(epd); + btrfs_tree_lock(eb); + } + + if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) { + btrfs_tree_unlock(eb); + if (!epd->sync_io) + return 0; + if (!flush) { + flush_write_bio(epd); + flush = 1; + } + wait_on_extent_buffer_writeback(eb); + btrfs_tree_lock(eb); + if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) { + printk(KERN_ERR "Um, ok?\n"); + btrfs_tree_unlock(eb); + return 0; + } + } + + if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) { + set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags); + btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN); + spin_lock(&fs_info->delalloc_lock); + if (fs_info->dirty_metadata_bytes >= eb->len) + fs_info->dirty_metadata_bytes -= eb->len; + else + WARN_ON(1); + spin_unlock(&fs_info->delalloc_lock); + ret = 1; + } + + btrfs_tree_unlock(eb); + + if (!ret) + return ret; + + num_pages = num_extent_pages(eb->start, eb->len); + for (i = 0; i < num_pages; i++) { + struct page *p = extent_buffer_page(eb, i); + + if (!trylock_page(p)) { + if (!flush) { + flush_write_bio(epd); + flush = 1; + } + lock_page(p); + } + } + + return ret; +} + +static void end_extent_buffer_writeback(struct extent_buffer *eb) +{ + clear_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags); + smp_mb__after_clear_bit(); + wake_up_bit(&eb->bflags, EXTENT_BUFFER_WRITEBACK); +} + +static void end_bio_extent_buffer_writepage(struct bio *bio, int err) +{ + int uptodate = err == 0; + struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; + struct extent_buffer *eb; + int done; + + do { + struct page *page = bvec->bv_page; + + bvec--; + eb = (struct extent_buffer *)page->private; + BUG_ON(!eb); + done = atomic_dec_and_test(&eb->io_pages); + + if (!uptodate || test_bit(EXTENT_BUFFER_IOERR, &eb->bflags)) { + set_bit(EXTENT_BUFFER_IOERR, &eb->bflags); + ClearPageUptodate(page); + SetPageError(page); + } + + end_page_writeback(page); + + if (!done) + continue; + + end_extent_buffer_writeback(eb); + } while (bvec >= bio->bi_io_vec); + + bio_put(bio); + +} + +static int write_one_eb(struct extent_buffer *eb, + struct btrfs_fs_info *fs_info, + struct writeback_control *wbc, + struct extent_page_data *epd) +{ + struct block_device *bdev = fs_info->fs_devices->latest_bdev; + u64 offset = eb->start; + unsigned long i, num_pages; + int rw = (epd->sync_io ? WRITE_SYNC : WRITE); + int ret; + + clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags); + num_pages = num_extent_pages(eb->start, eb->len); + atomic_set(&eb->io_pages, num_pages); + for (i = 0; i < num_pages; i++) { + struct page *p = extent_buffer_page(eb, i); + + clear_page_dirty_for_io(p); + set_page_writeback(p); + ret = submit_extent_page(rw, eb->tree, p, offset >> 9, + PAGE_CACHE_SIZE, 0, bdev, &epd->bio, + -1, end_bio_extent_buffer_writepage, + 0, 0, 0); + if (ret) { + set_bit(EXTENT_BUFFER_IOERR, &eb->bflags); + SetPageError(p); + if (atomic_sub_and_test(num_pages - i, &eb->io_pages)) + end_extent_buffer_writeback(eb); + ret = -EIO; + break; + } + offset += PAGE_CACHE_SIZE; + update_nr_written(p, wbc, 1); + unlock_page(p); + } + + if (unlikely(ret)) { + for (; i < num_pages; i++) { + struct page *p = extent_buffer_page(eb, i); + unlock_page(p); + } + } + + return ret; +} + +int btree_write_cache_pages(struct address_space *mapping, + struct writeback_control *wbc) +{ + struct extent_io_tree *tree = &BTRFS_I(mapping->host)->io_tree; + struct btrfs_fs_info *fs_info = BTRFS_I(mapping->host)->root->fs_info; + struct extent_buffer *eb, *prev_eb = NULL; + struct extent_page_data epd = { + .bio = NULL, + .tree = tree, + .extent_locked = 0, + .sync_io = wbc->sync_mode == WB_SYNC_ALL, + }; + int ret = 0; + int done = 0; + int nr_to_write_done = 0; + struct pagevec pvec; + int nr_pages; + pgoff_t index; + pgoff_t end; /* Inclusive */ + int scanned = 0; + int tag; + + pagevec_init(&pvec, 0); + if (wbc->range_cyclic) { + index = mapping->writeback_index; /* Start from prev offset */ + end = -1; + } else { + index = wbc->range_start >> PAGE_CACHE_SHIFT; + end = wbc->range_end >> PAGE_CACHE_SHIFT; + scanned = 1; + } + if (wbc->sync_mode == WB_SYNC_ALL) + tag = PAGECACHE_TAG_TOWRITE; + else + tag = PAGECACHE_TAG_DIRTY; +retry: + if (wbc->sync_mode == WB_SYNC_ALL) + tag_pages_for_writeback(mapping, index, end); + while (!done && !nr_to_write_done && (index <= end) && + (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag, + min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1))) { + unsigned i; + + scanned = 1; + for (i = 0; i < nr_pages; i++) { + struct page *page = pvec.pages[i]; + + if (!PagePrivate(page)) + continue; + + if (!wbc->range_cyclic && page->index > end) { + done = 1; + break; + } + + eb = (struct extent_buffer *)page->private; + if (!eb) { + WARN_ON(1); + continue; + } + + if (eb == prev_eb) + continue; + + if (!atomic_inc_not_zero(&eb->refs)) { + WARN_ON(1); + continue; + } + + prev_eb = eb; + ret = lock_extent_buffer_for_io(eb, fs_info, &epd); + if (!ret) { + free_extent_buffer(eb); + continue; + } + + ret = write_one_eb(eb, fs_info, wbc, &epd); + if (ret) { + done = 1; + free_extent_buffer(eb); + break; + } + free_extent_buffer(eb); + + /* + * the filesystem may choose to bump up nr_to_write. + * We have to make sure to honor the new nr_to_write + * at any time + */ + nr_to_write_done = wbc->nr_to_write <= 0; + } + pagevec_release(&pvec); + cond_resched(); + } + if (!scanned && !done) { + /* + * We hit the last page and there is more work to be done: wrap + * back to the start of the file + */ + scanned = 1; + index = 0; + goto retry; + } + flush_write_bio(&epd); + return ret; +} + /** * write_cache_pages - walk the list of dirty pages of the given address space and write all of them. * @mapping: address space structure to write @@ -3609,7 +3881,7 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree, #endif spin_lock_init(&eb->refs_lock); atomic_set(&eb->refs, 1); - atomic_set(&eb->pages_reading, 0); + atomic_set(&eb->io_pages, 0); if (len > MAX_INLINE_EXTENT_BUFFER_SIZE) { struct page **pages; @@ -3628,6 +3900,13 @@ static struct extent_buffer *__alloc_extent_buffer(struct extent_io_tree *tree, return eb; } +static int extent_buffer_under_io(struct extent_buffer *eb) +{ + return (atomic_read(&eb->io_pages) || + test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags) || + test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); +} + /* * Helper for releasing extent buffer page. */ @@ -3637,6 +3916,8 @@ static void btrfs_release_extent_buffer_page(struct extent_buffer *eb, unsigned long index; struct page *page; + BUG_ON(extent_buffer_under_io(eb)); + index = num_extent_pages(eb->start, eb->len); if (start_idx >= index) return; @@ -3655,6 +3936,7 @@ static void btrfs_release_extent_buffer_page(struct extent_buffer *eb, */ if (PagePrivate(page) && page->private == (unsigned long)eb) { + BUG_ON(test_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)); BUG_ON(PageDirty(page)); BUG_ON(PageWriteback(page)); /* @@ -3683,10 +3965,41 @@ static inline void btrfs_release_extent_buffer(struct extent_buffer *eb) __free_extent_buffer(eb); } +static void check_buffer_tree_ref(struct extent_buffer *eb) +{ + /* the ref bit is tricky. We have to make sure it is set + * if we have the buffer dirty. Otherwise the + * code to free a buffer can end up dropping a dirty + * page + * + * Once the ref bit is set, it won't go away while the + * buffer is dirty or in writeback, and it also won't + * go away while we have the reference count on the + * eb bumped. + * + * We can't just set the ref bit without bumping the + * ref on the eb because free_extent_buffer might + * see the ref bit and try to clear it. If this happens + * free_extent_buffer might end up dropping our original + * ref by mistake and freeing the page before we are able + * to add one more ref. + * + * So bump the ref count first, then set the bit. If someone + * beat us to it, drop the ref we added. + */ + if (!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) { + atomic_inc(&eb->refs); + if (test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) + atomic_dec(&eb->refs); + } +} + static void mark_extent_buffer_accessed(struct extent_buffer *eb) { unsigned long num_pages, i; + check_buffer_tree_ref(eb); + num_pages = num_extent_pages(eb->start, eb->len); for (i = 0; i < num_pages; i++) { struct page *p = extent_buffer_page(eb, i); @@ -3744,15 +4057,17 @@ struct extent_buffer *alloc_extent_buffer(struct extent_io_tree *tree, goto free_eb; } - /* + /* * Do this so attach doesn't complain and we need to * drop the ref the old guy had. */ ClearPagePrivate(p); + WARN_ON(PageDirty(p)); page_cache_release(p); } attach_extent_buffer_page(eb, p); spin_unlock(&mapping->private_lock); + WARN_ON(PageDirty(p)); mark_page_accessed(p); eb->pages[i] = p; if (!PageUptodate(p)) @@ -3788,8 +4103,7 @@ again: } /* add one reference for the tree */ spin_lock(&eb->refs_lock); - atomic_inc(&eb->refs); - set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags); + check_buffer_tree_ref(eb); spin_unlock(&eb->refs_lock); spin_unlock(&tree->buffer_lock); radix_tree_preload_end(); @@ -3849,90 +4163,15 @@ static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head) __free_extent_buffer(eb); } -static int extent_buffer_under_io(struct extent_buffer *eb, - struct page *locked_page) -{ - unsigned long num_pages, i; - - num_pages = num_extent_pages(eb->start, eb->len); - for (i = 0; i < num_pages; i++) { - struct page *page = eb->pages[i]; - int need_unlock = 0; - - if (!page) - continue; - - if (page != locked_page) { - if (!trylock_page(page)) - return 1; - need_unlock = 1; - } - - if (PageDirty(page) || PageWriteback(page)) { - if (need_unlock) - unlock_page(page); - return 1; - } - if (need_unlock) - unlock_page(page); - } - - return 0; -} - /* Expects to have eb->eb_lock already held */ static void release_extent_buffer(struct extent_buffer *eb, gfp_t mask) { WARN_ON(atomic_read(&eb->refs) == 0); if (atomic_dec_and_test(&eb->refs)) { struct extent_io_tree *tree = eb->tree; - int ret; spin_unlock(&eb->refs_lock); - might_sleep_if(mask & __GFP_WAIT); - ret = clear_extent_bit(tree, eb->start, - eb->start + eb->len - 1, -1, 0, 0, - NULL, mask); - if (ret < 0) { - unsigned long num_pages, i; - - num_pages = num_extent_pages(eb->start, eb->len); - /* - * We failed to clear the state bits which likely means - * ENOMEM, so just re-up the eb ref and continue, we - * will get freed later on via releasepage or something - * else and will be ok. - */ - spin_lock(&eb->tree->mapping->private_lock); - spin_lock(&eb->refs_lock); - set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags); - atomic_inc(&eb->refs); - - /* - * We may have started to reclaim the pages for a newly - * allocated eb, make sure we own all of them again. - */ - for (i = 0; i < num_pages; i++) { - struct page *page = eb->pages[i]; - - if (!page) { - WARN_ON(1); - continue; - } - - BUG_ON(!PagePrivate(page)); - if (page->private != (unsigned long)eb) { - ClearPagePrivate(page); - page_cache_release(page); - attach_extent_buffer_page(eb, page); - } - } - spin_unlock(&eb->refs_lock); - spin_unlock(&eb->tree->mapping->private_lock); - return; - } - spin_lock(&tree->buffer_lock); radix_tree_delete(&tree->buffer, eb->start >> PAGE_CACHE_SHIFT); @@ -3955,7 +4194,7 @@ void free_extent_buffer(struct extent_buffer *eb) spin_lock(&eb->refs_lock); if (atomic_read(&eb->refs) == 2 && test_bit(EXTENT_BUFFER_STALE, &eb->bflags) && - !extent_buffer_under_io(eb, NULL) && + !extent_buffer_under_io(eb) && test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) atomic_dec(&eb->refs); @@ -3974,20 +4213,20 @@ void free_extent_buffer_stale(struct extent_buffer *eb) spin_lock(&eb->refs_lock); set_bit(EXTENT_BUFFER_STALE, &eb->bflags); - if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb, NULL) && + if (atomic_read(&eb->refs) == 2 && !extent_buffer_under_io(eb) && test_and_clear_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) atomic_dec(&eb->refs); release_extent_buffer(eb, GFP_NOFS); } -int clear_extent_buffer_dirty(struct extent_io_tree *tree, - struct extent_buffer *eb) +int clear_extent_buffer_dirty(struct extent_buffer *eb) { unsigned long i; unsigned long num_pages; struct page *page; num_pages = num_extent_pages(eb->start, eb->len); + WARN_ON(atomic_read(&eb->refs) == 0); for (i = 0; i < num_pages; i++) { page = extent_buffer_page(eb, i); @@ -4008,25 +4247,30 @@ int clear_extent_buffer_dirty(struct extent_io_tree *tree, ClearPageError(page); unlock_page(page); } + WARN_ON(atomic_read(&eb->refs) == 0); return 0; } -int set_extent_buffer_dirty(struct extent_io_tree *tree, - struct extent_buffer *eb) +int set_extent_buffer_dirty(struct extent_buffer *eb) { unsigned long i; unsigned long num_pages; int was_dirty = 0; + check_buffer_tree_ref(eb); + was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags); + num_pages = num_extent_pages(eb->start, eb->len); WARN_ON(atomic_read(&eb->refs) == 0); + WARN_ON(!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)); + for (i = 0; i < num_pages; i++) - __set_page_dirty_nobuffers(extent_buffer_page(eb, i)); + set_page_dirty(extent_buffer_page(eb, i)); return was_dirty; } -static int __eb_straddles_pages(u64 start, u64 len) +static int range_straddles_pages(u64 start, u64 len) { if (len < PAGE_CACHE_SIZE) return 1; @@ -4037,25 +4281,14 @@ static int __eb_straddles_pages(u64 start, u64 len) return 0; } -static int eb_straddles_pages(struct extent_buffer *eb) -{ - return __eb_straddles_pages(eb->start, eb->len); -} - -int clear_extent_buffer_uptodate(struct extent_io_tree *tree, - struct extent_buffer *eb, - struct extent_state **cached_state) +int clear_extent_buffer_uptodate(struct extent_buffer *eb) { unsigned long i; struct page *page; unsigned long num_pages; - num_pages = num_extent_pages(eb->start, eb->len); clear_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); - - clear_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, - cached_state, GFP_NOFS); - + num_pages = num_extent_pages(eb->start, eb->len); for (i = 0; i < num_pages; i++) { page = extent_buffer_page(eb, i); if (page) @@ -4064,27 +4297,16 @@ int clear_extent_buffer_uptodate(struct extent_io_tree *tree, return 0; } -int set_extent_buffer_uptodate(struct extent_io_tree *tree, - struct extent_buffer *eb) +int set_extent_buffer_uptodate(struct extent_buffer *eb) { unsigned long i; struct page *page; unsigned long num_pages; + set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); num_pages = num_extent_pages(eb->start, eb->len); - - if (eb_straddles_pages(eb)) { - set_extent_uptodate(tree, eb->start, eb->start + eb->len - 1, - NULL, GFP_NOFS); - } for (i = 0; i < num_pages; i++) { page = extent_buffer_page(eb, i); - if ((i == 0 && (eb->start & (PAGE_CACHE_SIZE - 1))) || - ((i == num_pages - 1) && - ((eb->start + eb->len) & (PAGE_CACHE_SIZE - 1)))) { - check_page_uptodate(tree, page); - continue; - } SetPageUptodate(page); } return 0; @@ -4099,7 +4321,7 @@ int extent_range_uptodate(struct extent_io_tree *tree, int uptodate; unsigned long index; - if (__eb_straddles_pages(start, end - start + 1)) { + if (range_straddles_pages(start, end - start + 1)) { ret = test_range_bit(tree, start, end, EXTENT_UPTODATE, 1, NULL); if (ret) @@ -4121,35 +4343,9 @@ int extent_range_uptodate(struct extent_io_tree *tree, return pg_uptodate; } -int extent_buffer_uptodate(struct extent_io_tree *tree, - struct extent_buffer *eb, - struct extent_state *cached_state) +int extent_buffer_uptodate(struct extent_buffer *eb) { - int ret = 0; - unsigned long num_pages; - unsigned long i; - struct page *page; - int pg_uptodate = 1; - - if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)) - return 1; - - if (eb_straddles_pages(eb)) { - ret = test_range_bit(tree, eb->start, eb->start + eb->len - 1, - EXTENT_UPTODATE, 1, cached_state); - if (ret) - return ret; - } - - num_pages = num_extent_pages(eb->start, eb->len); - for (i = 0; i < num_pages; i++) { - page = extent_buffer_page(eb, i); - if (!PageUptodate(page)) { - pg_uptodate = 0; - break; - } - } - return pg_uptodate; + return test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); } int read_extent_buffer_pages(struct extent_io_tree *tree, @@ -4171,13 +4367,6 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags)) return 0; - if (eb_straddles_pages(eb)) { - if (test_range_bit(tree, eb->start, eb->start + eb->len - 1, - EXTENT_UPTODATE, 1, NULL)) { - return 0; - } - } - if (start) { WARN_ON(start < eb->start); start_i = (start >> PAGE_CACHE_SHIFT) - @@ -4207,7 +4396,7 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, goto unlock_exit; } - atomic_set(&eb->pages_reading, num_reads); + atomic_set(&eb->io_pages, num_reads); for (i = start_i; i < num_pages; i++) { page = extent_buffer_page(eb, i); if (!PageUptodate(page)) { @@ -4235,8 +4424,6 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, ret = -EIO; } - if (!ret) - set_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags); return ret; unlock_exit: @@ -4604,13 +4791,13 @@ int try_release_extent_buffer(struct page *page, gfp_t mask) eb = (struct extent_buffer *)page->private; BUG_ON(!eb); - /* + /* * This is a little awful but should be ok, we need to make sure that * the eb doesn't disappear out from under us while we're looking at * this page. */ spin_lock(&eb->refs_lock); - if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb, page)) { + if (atomic_read(&eb->refs) != 1 || extent_buffer_under_io(eb)) { spin_unlock(&eb->refs_lock); spin_unlock(&page->mapping->private_lock); return 0; -- cgit v1.2.3 From a098d8e8eec5a46a47b1bb74390746973d913a9c Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Wed, 21 Mar 2012 12:09:56 -0400 Subject: Btrfs: loop waiting on writeback lock_extent_buffer_for_io needs to loop around and make sure the writeback bits are not set. Signed-off-by: Chris Mason --- fs/btrfs/extent_io.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index c1b898d590d7..b71cc4547d47 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3010,12 +3010,12 @@ static int lock_extent_buffer_for_io(struct extent_buffer *eb, flush_write_bio(epd); flush = 1; } - wait_on_extent_buffer_writeback(eb); - btrfs_tree_lock(eb); - if (test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) { - printk(KERN_ERR "Um, ok?\n"); + while (1) { + wait_on_extent_buffer_writeback(eb); + btrfs_tree_lock(eb); + if (!test_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags)) + break; btrfs_tree_unlock(eb); - return 0; } } -- cgit v1.2.3 From ea466794084f55d8fcc100711cf17923bf57e962 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Mon, 26 Mar 2012 21:57:36 -0400 Subject: Btrfs: deal with read errors on extent buffers differently Since we need to read and write extent buffers in their entirety we can't use the normal bio_readpage_error stuff since it only works on a per page basis. So instead make it so that if we see an io error in endio we just mark the eb as having an IO error and then in btree_read_extent_buffer_pages we will manually try other mirrors and then overwrite the bad mirror if we find a good copy. This works with larger than page size blocks. Thanks, Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/extent_io.c | 42 ++++++++++++++++++++++++++++++++---------- 1 file changed, 32 insertions(+), 10 deletions(-) (limited to 'fs/btrfs/extent_io.c') diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index b71cc4547d47..49a368593a16 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -1915,6 +1915,26 @@ int repair_io_failure(struct btrfs_mapping_tree *map_tree, u64 start, return 0; } +int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb, + int mirror_num) +{ + struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree; + u64 start = eb->start; + unsigned long i, num_pages = num_extent_pages(eb->start, eb->len); + int ret; + + for (i = 0; i < num_pages; i++) { + struct page *p = extent_buffer_page(eb, i); + ret = repair_io_failure(map_tree, start, PAGE_CACHE_SIZE, + start, p, mirror_num); + if (ret) + break; + start += PAGE_CACHE_SIZE; + } + + return ret; +} + /* * each time an IO finishes, we do a fast check in the IO failure tree * to see if we need to process or clean up an io_failure_record @@ -2261,6 +2281,7 @@ static void end_bio_extent_readpage(struct bio *bio, int err) u64 start; u64 end; int whole_page; + int failed_mirror; int ret; if (err) @@ -2307,9 +2328,16 @@ static void end_bio_extent_readpage(struct bio *bio, int err) else clean_io_failure(start, page); } - if (!uptodate) { - int failed_mirror; + + if (!uptodate) failed_mirror = (int)(unsigned long)bio->bi_bdev; + + if (!uptodate && tree->ops && tree->ops->readpage_io_failed_hook) { + ret = tree->ops->readpage_io_failed_hook(page, failed_mirror); + if (!ret && !err && + test_bit(BIO_UPTODATE, &bio->bi_flags)) + uptodate = 1; + } else if (!uptodate) { /* * The generic bio_readpage_error handles errors the * following way: If possible, new read requests are @@ -2323,7 +2351,6 @@ static void end_bio_extent_readpage(struct bio *bio, int err) ret = bio_readpage_error(bio, page, start, end, failed_mirror, NULL); if (ret == 0) { -error_handled: uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); if (err) @@ -2331,13 +2358,6 @@ error_handled: uncache_state(&cached); continue; } - if (tree->ops && tree->ops->readpage_io_failed_hook) { - ret = tree->ops->readpage_io_failed_hook( - bio, page, start, end, - failed_mirror, state); - if (ret == 0) - goto error_handled; - } } if (uptodate && tree->track_uptodate) { @@ -4396,6 +4416,8 @@ int read_extent_buffer_pages(struct extent_io_tree *tree, goto unlock_exit; } + clear_bit(EXTENT_BUFFER_IOERR, &eb->bflags); + eb->failed_mirror = 0; atomic_set(&eb->io_pages, num_reads); for (i = start_i; i < num_pages; i++) { page = extent_buffer_page(eb, i); -- cgit v1.2.3