[PATCH AUTOSEL 5.5 048/106] ext4: do not commit super on read-only bdev

[PATCH AUTOSEL 5.5 048/106] ext4: do not commit super on read-only bdev

[Sasha Levin]

From: Eric Sandeen <sandeen@redhat.com>

[ Upstream commit c96e2b8564adfb8ac14469ebc51ddc1bfecb3ae2 ]

Under some circumstances we may encounter a filesystem error on a
read-only block device, and if we try to save the error info to the
superblock and commit it, we'll wind up with a noisy error and
backtrace, i.e.:

[ 3337.146838] EXT4-fs error (device pmem1p2): ext4_get_journal_inode:4634: comm mount: inode #0: comm mount: iget: illegal inode #
------------[ cut here ]------------
generic_make_request: Trying to write to read-only block-device pmem1p2 (partno 2)
WARNING: CPU: 107 PID: 115347 at block/blk-core.c:788 generic_make_request_checks+0x6b4/0x7d0
...

To avoid this, commit the error info in the superblock only if the
block device is writable.

Reported-by: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/4b6e774d-cc00-3469-7abb-108eb151071a@sandeen.net
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/super.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 71e2b80ff4aae..f59c587faccb5 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -389,7 +389,8 @@ static void save_error_info(struct super_block *sb, const char *func,
 			    unsigned int line)
 {
 	__save_error_info(sb, func, line);
-	ext4_commit_super(sb, 1);
+	if (!bdev_read_only(sb->s_bdev))
+		ext4_commit_super(sb, 1);
 }
 
 /*
-- 
2.20.1

[PATCH AUTOSEL 5.5 049/106] ext4: fix incorrect group count in ext4_fill_super error message

[Sasha Levin]

From: Josh Triplett <josh@joshtriplett.org>

[ Upstream commit df41460a21b06a76437af040d90ccee03888e8e5 ]

ext4_fill_super doublechecks the number of groups before mounting; if
that check fails, the resulting error message prints the group count
from the ext4_sb_info sbi, which hasn't been set yet. Print the freshly
computed group count instead (which at that point has just been computed
in "blocks_count").

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Fixes: 4ec1102813798 ("ext4: Add sanity checks for the superblock before mounting the filesystem")
Link: https://lore.kernel.org/r/8b957cd1513fcc4550fe675c10bcce2175c33a49.1585431964.git.josh@joshtriplett.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/super.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f59c587faccb5..3b4fc5036d91b 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4242,9 +4242,9 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
 	do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
 	if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
-		ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
+		ext4_msg(sb, KERN_WARNING, "groups count too large: %llu "
 		       "(block count %llu, first data block %u, "
-		       "blocks per group %lu)", sbi->s_groups_count,
+		       "blocks per group %lu)", blocks_count,
 		       ext4_blocks_count(es),
 		       le32_to_cpu(es->s_first_data_block),
 		       EXT4_BLOCKS_PER_GROUP(sb));
-- 
2.20.1

[PATCH AUTOSEL 5.5 050/106] ext4: fix incorrect inodes per group in error message

[Sasha Levin]

From: Josh Triplett <josh@joshtriplett.org>

[ Upstream commit b9c538da4e52a7b79dfcf4cfa487c46125066dfb ]

If ext4_fill_super detects an invalid number of inodes per group, the
resulting error message printed the number of blocks per group, rather
than the number of inodes per group. Fix it to print the correct value.

Fixes: cd6bb35bf7f6d ("ext4: use more strict checks for inodes_per_block on mount")
Link: https://lore.kernel.org/r/8be03355983a08e5d4eed480944613454d7e2550.1585434649.git.josh@joshtriplett.org
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext4/super.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 3b4fc5036d91b..2b081f26a9f13 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4113,7 +4113,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||
 	    sbi->s_inodes_per_group > blocksize * 8) {
 		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",
-			 sbi->s_blocks_per_group);
+			 sbi->s_inodes_per_group);
 		goto failed_mount;
 	}
 	sbi->s_itb_per_group = sbi->s_inodes_per_group /
-- 
2.20.1

[PATCH AUTOSEL 5.5 092/106] ext2: fix empty body warnings when -Wextra is used

[Sasha Levin]

From: Randy Dunlap <rdunlap@infradead.org>

[ Upstream commit 44a52022e7f15cbaab957df1c14f7a4f527ef7cf ]

When EXT2_ATTR_DEBUG is not defined, modify the 2 debug macros
to use the no_printk() macro instead of <nothing>.
This fixes gcc warnings when -Wextra is used:

../fs/ext2/xattr.c:252:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../fs/ext2/xattr.c:258:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../fs/ext2/xattr.c:330:42: warning: suggest braces around empty body in an ‘if’ statement [-Wempty-body]
../fs/ext2/xattr.c:872:45: warning: suggest braces around empty body in an ‘else’ statement [-Wempty-body]

I have verified that the only object code change (with gcc 7.5.0) is
the reversal of some instructions from 'cmp a,b' to 'cmp b,a'.

Link: https://lore.kernel.org/r/e18a7395-61fb-2093-18e8-ed4f8cf56248@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jan Kara <jack@suse.com>
Cc: linux-ext4@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext2/xattr.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
index 0456bc990b5ee..b91f99d9482e9 100644
--- a/fs/ext2/xattr.c
+++ b/fs/ext2/xattr.c
@@ -56,6 +56,7 @@
 
 #include <linux/buffer_head.h>
 #include <linux/init.h>
+#include <linux/printk.h>
 #include <linux/slab.h>
 #include <linux/mbcache.h>
 #include <linux/quotaops.h>
@@ -84,8 +85,8 @@
 		printk("\n"); \
 	} while (0)
 #else
-# define ea_idebug(f...)
-# define ea_bdebug(f...)
+# define ea_idebug(inode, f...)	no_printk(f)
+# define ea_bdebug(bh, f...)	no_printk(f)
 #endif
 
 static int ext2_xattr_set2(struct inode *, struct buffer_head *,
-- 
2.20.1

[PATCH AUTOSEL 5.5 097/106] ext2: fix debug reference to ext2_xattr_cache

[Sasha Levin]

From: Jan Kara <jack@suse.cz>

[ Upstream commit 32302085a8d90859c40cf1a5e8313f575d06ec75 ]

Fix a debug-only build error in ext2/xattr.c:

When building without extra debugging, (and with another patch that uses
no_printk() instead of <empty> for the ext2-xattr debug-print macros,
this build error happens:

../fs/ext2/xattr.c: In function ‘ext2_xattr_cache_insert’:
../fs/ext2/xattr.c:869:18: error: ‘ext2_xattr_cache’ undeclared (first use in
this function); did you mean ‘ext2_xattr_list’?
     atomic_read(&ext2_xattr_cache->c_entry_count));

Fix the problem by removing cached entry count from the debug message
since otherwise we'd have to export the mbcache structure just for that.

Fixes: be0726d33cb8 ("ext2: convert to mbcache2")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ext2/xattr.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
index b91f99d9482e9..62acbe27d8bf4 100644
--- a/fs/ext2/xattr.c
+++ b/fs/ext2/xattr.c
@@ -865,8 +865,7 @@ ext2_xattr_cache_insert(struct mb_cache *cache, struct buffer_head *bh)
 				      true);
 	if (error) {
 		if (error == -EBUSY) {
-			ea_bdebug(bh, "already in cache (%d cache entries)",
-				atomic_read(&ext2_xattr_cache->c_entry_count));
+			ea_bdebug(bh, "already in cache");
 			error = 0;
 		}
 	} else
-- 
2.20.1