From 15b49132fc972c63894592f218ea5a9a61b1a18f Mon Sep 17 00:00:00 2001 From: Eryu Guan Date: Sat, 12 Jan 2013 16:33:25 -0500 Subject: ext4: check bh in ext4_read_block_bitmap() Validate the bh pointer before using it, since ext4_read_block_bitmap_nowait() might return NULL. I've seen this in fsfuzz testing. EXT4-fs error (device loop0): ext4_read_block_bitmap_nowait:385: comm touch: Cannot get buffer for block bitmap - block_group = 0, block_bitmap = 3925999616 BUG: unable to handle kernel NULL pointer dereference at (null) IP: [] ext4_wait_block_bitmap+0x25/0xe0 ... Call Trace: [] ext4_read_block_bitmap+0x35/0x60 [] ext4_free_blocks+0x236/0xb80 [] ? __getblk+0x36/0x70 [] ? __find_get_block+0x8f/0x210 [] ? kmem_cache_free+0x33/0x140 [] ext4_xattr_release_block+0x1b5/0x1d0 [] ext4_xattr_delete_inode+0xbe/0x100 [] ext4_free_inode+0x7c/0x4d0 [] ? ext4_mark_inode_dirty+0x88/0x230 [] ext4_evict_inode+0x32c/0x490 [] evict+0xa7/0x1c0 [] iput_final+0xe3/0x170 [] iput+0x3e/0x50 [] ext4_add_nondir+0x4d/0x90 [] ext4_create+0xeb/0x170 [] vfs_create+0xac/0xd0 [] lookup_open+0x185/0x1c0 [] ? selinux_inode_permission+0xa9/0x170 [] do_last+0x2d4/0x7a0 [] path_openat+0xb3/0x480 [] ? handle_mm_fault+0x251/0x3b0 [] do_filp_open+0x49/0xa0 [] ? __alloc_fd+0xdd/0x150 [] do_sys_open+0x108/0x1f0 [] sys_open+0x21/0x30 [] system_call_fastpath+0x16/0x1b Also fix comment for ext4_read_block_bitmap_nowait() Signed-off-by: Eryu Guan Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org --- fs/ext4/balloc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'fs/ext4/balloc.c') diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index cf1821784a16..33938c120c85 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -358,7 +358,7 @@ void ext4_validate_block_bitmap(struct super_block *sb, } /** - * ext4_read_block_bitmap() + * ext4_read_block_bitmap_nowait() * @sb: super block * @block_group: given block group * @@ -457,6 +457,8 @@ ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group) struct buffer_head *bh; bh = ext4_read_block_bitmap_nowait(sb, block_group); + if (!bh) + return NULL; if (ext4_wait_block_bitmap(sb, block_group, bh)) { put_bh(bh); return NULL; -- cgit v1.2.3 From 304e220f0879198b1f5309ad6f0be862b4009491 Mon Sep 17 00:00:00 2001 From: Lukas Czerner Date: Fri, 22 Feb 2013 15:27:52 -0500 Subject: ext4: fix free clusters calculation in bigalloc filesystem ext4_has_free_clusters() should tell us whether there is enough free clusters to allocate, however number of free clusters in the file system is converted to blocks using EXT4_C2B() which is not only wrong use of the macro (we should have used EXT4_NUM_B2C) but it's also completely wrong concept since everything else is in cluster units. Moreover when calculating number of root clusters we should be using macro EXT4_NUM_B2C() instead of EXT4_B2C() otherwise the result might be off by one. However r_blocks_count should always be a multiple of the cluster ratio so doing a plain bit shift should be enough here. We avoid using EXT4_B2C() because it's confusing. As a result of the first problem number of free clusters is much bigger than it should have been and ext4_has_free_clusters() would return 1 even if there is really not enough free clusters available. Fix this by removing the EXT4_C2B() conversion of free clusters and using bit shift when calculating number of root clusters. This bug affects number of xfstests tests covering file system ENOSPC situation handling. With this patch most of the ENOSPC problems with bigalloc file system disappear, especially the errors caused by delayed allocation not having enough space when the actual allocation is finally requested. Signed-off-by: Lukas Czerner Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org --- fs/ext4/balloc.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'fs/ext4/balloc.c') diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 33938c120c85..2f2e0da1a6b7 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -484,11 +484,16 @@ static int ext4_has_free_clusters(struct ext4_sb_info *sbi, free_clusters = percpu_counter_read_positive(fcc); dirty_clusters = percpu_counter_read_positive(dcc); - root_clusters = EXT4_B2C(sbi, ext4_r_blocks_count(sbi->s_es)); + + /* + * r_blocks_count should always be multiple of the cluster ratio so + * we are safe to do a plane bit shift only. + */ + root_clusters = ext4_r_blocks_count(sbi->s_es) >> sbi->s_cluster_bits; if (free_clusters - (nclusters + root_clusters + dirty_clusters) < EXT4_FREECLUSTERS_WATERMARK) { - free_clusters = EXT4_C2B(sbi, percpu_counter_sum_positive(fcc)); + free_clusters = percpu_counter_sum_positive(fcc); dirty_clusters = percpu_counter_sum_positive(dcc); } /* Check whether we have space after accounting for current -- cgit v1.2.3 From 810da240f221d64bf90020f25941b05b378186fe Mon Sep 17 00:00:00 2001 From: Lukas Czerner Date: Sat, 2 Mar 2013 17:18:58 -0500 Subject: ext4: convert number of blocks to clusters properly We're using macro EXT4_B2C() to convert number of blocks to number of clusters for bigalloc file systems. However, we should be using EXT4_NUM_B2C(). Signed-off-by: Lukas Czerner Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org --- fs/ext4/balloc.c | 2 +- fs/ext4/mballoc.c | 8 ++++---- fs/ext4/resize.c | 6 +++--- fs/ext4/super.c | 2 +- 4 files changed, 9 insertions(+), 9 deletions(-) (limited to 'fs/ext4/balloc.c') diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 2f2e0da1a6b7..92e68b33fffd 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -635,7 +635,7 @@ ext4_fsblk_t ext4_count_free_clusters(struct super_block *sb) brelse(bitmap_bh); printk(KERN_DEBUG "ext4_count_free_clusters: stored = %llu" ", computed = %llu, %llu\n", - EXT4_B2C(EXT4_SB(sb), ext4_free_blocks_count(es)), + EXT4_NUM_B2C(EXT4_SB(sb), ext4_free_blocks_count(es)), desc_count, bitmap_count); return bitmap_count; #else diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 6540ebe058e3..7bb713a46fe4 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -3419,7 +3419,7 @@ ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) win = offs; ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical - - EXT4_B2C(sbi, win); + EXT4_NUM_B2C(sbi, win); BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical); BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len); } @@ -4565,7 +4565,7 @@ do_more: EXT4_BLOCKS_PER_GROUP(sb); count -= overflow; } - count_clusters = EXT4_B2C(sbi, count); + count_clusters = EXT4_NUM_B2C(sbi, count); bitmap_bh = ext4_read_block_bitmap(sb, block_group); if (!bitmap_bh) { err = -EIO; @@ -4807,11 +4807,11 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb, ext4_group_desc_csum_set(sb, block_group, desc); ext4_unlock_group(sb, block_group); percpu_counter_add(&sbi->s_freeclusters_counter, - EXT4_B2C(sbi, blocks_freed)); + EXT4_NUM_B2C(sbi, blocks_freed)); if (sbi->s_log_groups_per_flex) { ext4_group_t flex_group = ext4_flex_group(sbi, block_group); - atomic_add(EXT4_B2C(sbi, blocks_freed), + atomic_add(EXT4_NUM_B2C(sbi, blocks_freed), &sbi->s_flex_groups[flex_group].free_clusters); } diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index c7f4d7584669..b2c8ee56eb98 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1247,7 +1247,7 @@ static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb, ext4_inode_table_set(sb, gdp, group_data->inode_table); ext4_free_group_clusters_set(sb, gdp, - EXT4_B2C(sbi, group_data->free_blocks_count)); + EXT4_NUM_B2C(sbi, group_data->free_blocks_count)); ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb)); if (ext4_has_group_desc_csum(sb)) ext4_itable_unused_set(sb, gdp, @@ -1349,7 +1349,7 @@ static void ext4_update_super(struct super_block *sb, /* Update the free space counts */ percpu_counter_add(&sbi->s_freeclusters_counter, - EXT4_B2C(sbi, free_blocks)); + EXT4_NUM_B2C(sbi, free_blocks)); percpu_counter_add(&sbi->s_freeinodes_counter, EXT4_INODES_PER_GROUP(sb) * flex_gd->count); @@ -1360,7 +1360,7 @@ static void ext4_update_super(struct super_block *sb, sbi->s_log_groups_per_flex) { ext4_group_t flex_group; flex_group = ext4_flex_group(sbi, group_data[0].group); - atomic_add(EXT4_B2C(sbi, free_blocks), + atomic_add(EXT4_NUM_B2C(sbi, free_blocks), &sbi->s_flex_groups[flex_group].free_clusters); atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count, &sbi->s_flex_groups[flex_group].free_inodes); diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 6ac9c8a3eb08..990ceab2e2bc 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3162,7 +3162,7 @@ int ext4_calculate_overhead(struct super_block *sb) } /* Add the journal blocks as well */ if (sbi->s_journal) - overhead += EXT4_B2C(sbi, sbi->s_journal->j_maxlen); + overhead += EXT4_NUM_B2C(sbi, sbi->s_journal->j_maxlen); sbi->s_overhead = overhead; smp_wmb(); -- cgit v1.2.3