* [PATCH RESEND v3] f2fs: fix concurrent problem for updating free bitmap [not found] <CGME20171122080814epcas5p4694a196adb1a55eeb8ac086ca0aace05@epcas5p4.samsung.com> @ 2017-11-22 8:07 ` LiFan 2017-11-23 13:06 ` Chao Yu 0 siblings, 1 reply; 2+ messages in thread From: LiFan @ 2017-11-22 8:07 UTC (permalink / raw) To: 'Chao Yu', 'Chao Yu', 'Jaegeuk Kim' Cc: linux-kernel, linux-f2fs-devel alloc_nid_failed and scan_nat_page can be called at the same time, and we haven't protected add_free_nid and update_free_nid_bitmap with the same nid_list_lock. That could lead to Thread A Thread B - __build_free_nids - scan_nat_page - add_free_nid - alloc_nid_failed - update_free_nid_bitmap - update_free_nid_bitmap scan_nat_page will clear the free bitmap since the nid is PREALLOC_NID, but alloc_nid_failed needs to set the free bitmap. This results in free nid with free bitmap cleared. This patch update the bitmap under the same nid_list_lock in add_free_nid. And use __GFP_NOFAIL to make sure to update status of free nid correctly. Signed-off-by: Fan li <fanofcode.li@samsung.com> --- fs/f2fs/node.c | 85 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 43 insertions(+), 42 deletions(-) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index fe1fc66..8d5a06b 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1831,8 +1831,33 @@ static void __move_free_nid(struct f2fs_sb_info *sbi, struct free_nid *i, } } +static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, + bool set, bool build) +{ + struct f2fs_nm_info *nm_i = NM_I(sbi); + unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid); + unsigned int nid_ofs = nid - START_NID(nid); + + if (!test_bit_le(nat_ofs, nm_i->nat_block_bitmap)) + return; + + if (set) { + if (test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs])) + return; + __set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); + nm_i->free_nid_count[nat_ofs]++; + } else { + if (!test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs])) + return; + __clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); + if (!build) + nm_i->free_nid_count[nat_ofs]--; + } +} + /* return if the nid is recognized as free */ -static bool add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build) +static bool add_free_nid(struct f2fs_sb_info *sbi, + nid_t nid, bool build, bool update) { struct f2fs_nm_info *nm_i = NM_I(sbi); struct free_nid *i, *e; @@ -1848,8 +1873,7 @@ static bool add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build) i->nid = nid; i->state = FREE_NID; - if (radix_tree_preload(GFP_NOFS)) - goto err; + radix_tree_preload(GFP_NOFS | __GFP_NOFAIL); spin_lock(&nm_i->nid_list_lock); @@ -1890,9 +1914,14 @@ static bool add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build) ret = true; err = __insert_free_nid(sbi, i, FREE_NID); err_out: + if (update) { + update_free_nid_bitmap(sbi, nid, ret, build); + if (!build) + nm_i->available_nids++; + } spin_unlock(&nm_i->nid_list_lock); radix_tree_preload_end(); -err: + if (err) kmem_cache_free(free_nid_slab, i); return ret; @@ -1916,30 +1945,6 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid) kmem_cache_free(free_nid_slab, i); } -static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, - bool set, bool build) -{ - struct f2fs_nm_info *nm_i = NM_I(sbi); - unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid); - unsigned int nid_ofs = nid - START_NID(nid); - - if (!test_bit_le(nat_ofs, nm_i->nat_block_bitmap)) - return; - - if (set) { - if (test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs])) - return; - __set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); - nm_i->free_nid_count[nat_ofs]++; - } else { - if (!test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs])) - return; - __clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); - if (!build) - nm_i->free_nid_count[nat_ofs]--; - } -} - static void scan_nat_page(struct f2fs_sb_info *sbi, struct page *nat_page, nid_t start_nid) { @@ -1957,18 +1962,18 @@ static void scan_nat_page(struct f2fs_sb_info *sbi, i = start_nid % NAT_ENTRY_PER_BLOCK; for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) { - bool freed = false; - if (unlikely(start_nid >= nm_i->max_nid)) break; blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr); f2fs_bug_on(sbi, blk_addr == NEW_ADDR); - if (blk_addr == NULL_ADDR) - freed = add_free_nid(sbi, start_nid, true); - spin_lock(&NM_I(sbi)->nid_list_lock); - update_free_nid_bitmap(sbi, start_nid, freed, true); - spin_unlock(&NM_I(sbi)->nid_list_lock); + if (blk_addr == NULL_ADDR) { + add_free_nid(sbi, start_nid, true, true); + } else { + spin_lock(&NM_I(sbi)->nid_list_lock); + update_free_nid_bitmap(sbi, start_nid, false, true); + spin_unlock(&NM_I(sbi)->nid_list_lock); + } } } @@ -1986,7 +1991,7 @@ static void scan_curseg_cache(struct f2fs_sb_info *sbi) addr = le32_to_cpu(nat_in_journal(journal, i).block_addr); nid = le32_to_cpu(nid_in_journal(journal, i)); if (addr == NULL_ADDR) - add_free_nid(sbi, nid, true); + add_free_nid(sbi, nid, true, false); else remove_free_nid(sbi, nid); } @@ -2013,7 +2018,7 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi) break; nid = i * NAT_ENTRY_PER_BLOCK + idx; - add_free_nid(sbi, nid, true); + add_free_nid(sbi, nid, true, false); if (nm_i->nid_cnt[FREE_NID] >= MAX_FREE_NIDS) goto out; @@ -2516,11 +2521,7 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi, nat_reset_flag(ne); __clear_nat_cache_dirty(NM_I(sbi), set, ne); if (nat_get_blkaddr(ne) == NULL_ADDR) { - add_free_nid(sbi, nid, false); - spin_lock(&NM_I(sbi)->nid_list_lock); - NM_I(sbi)->available_nids++; - update_free_nid_bitmap(sbi, nid, true, false); - spin_unlock(&NM_I(sbi)->nid_list_lock); + add_free_nid(sbi, nid, false, true); } else { spin_lock(&NM_I(sbi)->nid_list_lock); update_free_nid_bitmap(sbi, nid, false, false); -- 2.7.4 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH RESEND v3] f2fs: fix concurrent problem for updating free bitmap 2017-11-22 8:07 ` [PATCH RESEND v3] f2fs: fix concurrent problem for updating free bitmap LiFan @ 2017-11-23 13:06 ` Chao Yu 0 siblings, 0 replies; 2+ messages in thread From: Chao Yu @ 2017-11-23 13:06 UTC (permalink / raw) To: LiFan, 'Chao Yu', 'Jaegeuk Kim' Cc: linux-kernel, linux-f2fs-devel On 2017/11/22 16:07, LiFan wrote: > alloc_nid_failed and scan_nat_page can be called at the same time, > and we haven't protected add_free_nid and update_free_nid_bitmap > with the same nid_list_lock. That could lead to > > Thread A Thread B > - __build_free_nids > - scan_nat_page > - add_free_nid > - alloc_nid_failed > - update_free_nid_bitmap > - update_free_nid_bitmap > > scan_nat_page will clear the free bitmap since the nid is PREALLOC_NID, > but alloc_nid_failed needs to set the free bitmap. This results in > free nid with free bitmap cleared. > This patch update the bitmap under the same nid_list_lock in add_free_nid. > And use __GFP_NOFAIL to make sure to update status of free nid correctly. > > Signed-off-by: Fan li <fanofcode.li@samsung.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Thanks, > --- > fs/f2fs/node.c | 85 +++++++++++++++++++++++++++++----------------------------- > 1 file changed, 43 insertions(+), 42 deletions(-) > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > index fe1fc66..8d5a06b 100644 > --- a/fs/f2fs/node.c > +++ b/fs/f2fs/node.c > @@ -1831,8 +1831,33 @@ static void __move_free_nid(struct f2fs_sb_info *sbi, struct free_nid *i, > } > } > > +static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, > + bool set, bool build) > +{ > + struct f2fs_nm_info *nm_i = NM_I(sbi); > + unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid); > + unsigned int nid_ofs = nid - START_NID(nid); > + > + if (!test_bit_le(nat_ofs, nm_i->nat_block_bitmap)) > + return; > + > + if (set) { > + if (test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs])) > + return; > + __set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); > + nm_i->free_nid_count[nat_ofs]++; > + } else { > + if (!test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs])) > + return; > + __clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); > + if (!build) > + nm_i->free_nid_count[nat_ofs]--; > + } > +} > + > /* return if the nid is recognized as free */ > -static bool add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build) > +static bool add_free_nid(struct f2fs_sb_info *sbi, > + nid_t nid, bool build, bool update) > { > struct f2fs_nm_info *nm_i = NM_I(sbi); > struct free_nid *i, *e; > @@ -1848,8 +1873,7 @@ static bool add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build) > i->nid = nid; > i->state = FREE_NID; > > - if (radix_tree_preload(GFP_NOFS)) > - goto err; > + radix_tree_preload(GFP_NOFS | __GFP_NOFAIL); > > spin_lock(&nm_i->nid_list_lock); > > @@ -1890,9 +1914,14 @@ static bool add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build) > ret = true; > err = __insert_free_nid(sbi, i, FREE_NID); > err_out: > + if (update) { > + update_free_nid_bitmap(sbi, nid, ret, build); > + if (!build) > + nm_i->available_nids++; > + } > spin_unlock(&nm_i->nid_list_lock); > radix_tree_preload_end(); > -err: > + > if (err) > kmem_cache_free(free_nid_slab, i); > return ret; > @@ -1916,30 +1945,6 @@ static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid) > kmem_cache_free(free_nid_slab, i); > } > > -static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid, > - bool set, bool build) > -{ > - struct f2fs_nm_info *nm_i = NM_I(sbi); > - unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid); > - unsigned int nid_ofs = nid - START_NID(nid); > - > - if (!test_bit_le(nat_ofs, nm_i->nat_block_bitmap)) > - return; > - > - if (set) { > - if (test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs])) > - return; > - __set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); > - nm_i->free_nid_count[nat_ofs]++; > - } else { > - if (!test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs])) > - return; > - __clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]); > - if (!build) > - nm_i->free_nid_count[nat_ofs]--; > - } > -} > - > static void scan_nat_page(struct f2fs_sb_info *sbi, > struct page *nat_page, nid_t start_nid) > { > @@ -1957,18 +1962,18 @@ static void scan_nat_page(struct f2fs_sb_info *sbi, > i = start_nid % NAT_ENTRY_PER_BLOCK; > > for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) { > - bool freed = false; > - > if (unlikely(start_nid >= nm_i->max_nid)) > break; > > blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr); > f2fs_bug_on(sbi, blk_addr == NEW_ADDR); > - if (blk_addr == NULL_ADDR) > - freed = add_free_nid(sbi, start_nid, true); > - spin_lock(&NM_I(sbi)->nid_list_lock); > - update_free_nid_bitmap(sbi, start_nid, freed, true); > - spin_unlock(&NM_I(sbi)->nid_list_lock); > + if (blk_addr == NULL_ADDR) { > + add_free_nid(sbi, start_nid, true, true); > + } else { > + spin_lock(&NM_I(sbi)->nid_list_lock); > + update_free_nid_bitmap(sbi, start_nid, false, true); > + spin_unlock(&NM_I(sbi)->nid_list_lock); > + } > } > } > > @@ -1986,7 +1991,7 @@ static void scan_curseg_cache(struct f2fs_sb_info *sbi) > addr = le32_to_cpu(nat_in_journal(journal, i).block_addr); > nid = le32_to_cpu(nid_in_journal(journal, i)); > if (addr == NULL_ADDR) > - add_free_nid(sbi, nid, true); > + add_free_nid(sbi, nid, true, false); > else > remove_free_nid(sbi, nid); > } > @@ -2013,7 +2018,7 @@ static void scan_free_nid_bits(struct f2fs_sb_info *sbi) > break; > > nid = i * NAT_ENTRY_PER_BLOCK + idx; > - add_free_nid(sbi, nid, true); > + add_free_nid(sbi, nid, true, false); > > if (nm_i->nid_cnt[FREE_NID] >= MAX_FREE_NIDS) > goto out; > @@ -2516,11 +2521,7 @@ static void __flush_nat_entry_set(struct f2fs_sb_info *sbi, > nat_reset_flag(ne); > __clear_nat_cache_dirty(NM_I(sbi), set, ne); > if (nat_get_blkaddr(ne) == NULL_ADDR) { > - add_free_nid(sbi, nid, false); > - spin_lock(&NM_I(sbi)->nid_list_lock); > - NM_I(sbi)->available_nids++; > - update_free_nid_bitmap(sbi, nid, true, false); > - spin_unlock(&NM_I(sbi)->nid_list_lock); > + add_free_nid(sbi, nid, false, true); > } else { > spin_lock(&NM_I(sbi)->nid_list_lock); > update_free_nid_bitmap(sbi, nid, false, false); > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot ^ permalink raw reply [flat|nested] 2+ messages in thread
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2017-11-22 8:07 ` [PATCH RESEND v3] f2fs: fix concurrent problem for updating free bitmap LiFan
2017-11-23 13:06 ` Chao Yu
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