From a4d2aadca184ece182418950d45ba4ffc7b652d2 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Sun, 29 Jul 2018 15:48:00 -0400 Subject: ext4: sysfs: print ext4_super_block fields as little-endian While working on extended rand for last_error/first_error timestamps, I noticed that the endianess is wrong; we access the little-endian fields in struct ext4_super_block as native-endian when we print them. This adds a special case in ext4_attr_show() and ext4_attr_store() to byteswap the superblock fields if needed. In older kernels, this code was part of super.c, it got moved to sysfs.c in linux-4.4. Cc: stable@vger.kernel.org Fixes: 52c198c6820f ("ext4: add sysfs entry showing whether the fs contains errors") Reviewed-by: Andreas Dilger Signed-off-by: Arnd Bergmann Signed-off-by: Theodore Ts'o --- fs/ext4/sysfs.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'fs/ext4/sysfs.c') diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c index f34da0bb8f17..b970a200f20c 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -274,8 +274,12 @@ static ssize_t ext4_attr_show(struct kobject *kobj, case attr_pointer_ui: if (!ptr) return 0; - return snprintf(buf, PAGE_SIZE, "%u\n", - *((unsigned int *) ptr)); + if (a->attr_ptr == ptr_ext4_super_block_offset) + return snprintf(buf, PAGE_SIZE, "%u\n", + le32_to_cpup(ptr)); + else + return snprintf(buf, PAGE_SIZE, "%u\n", + *((unsigned int *) ptr)); case attr_pointer_atomic: if (!ptr) return 0; @@ -308,7 +312,10 @@ static ssize_t ext4_attr_store(struct kobject *kobj, ret = kstrtoul(skip_spaces(buf), 0, &t); if (ret) return ret; - *((unsigned int *) ptr) = t; + if (a->attr_ptr == ptr_ext4_super_block_offset) + *((__le32 *) ptr) = cpu_to_le32(t); + else + *((unsigned int *) ptr) = t; return len; case attr_inode_readahead: return inode_readahead_blks_store(sbi, buf, len); -- cgit v1.2.3 From 6a0678a79bb3a4e5fc1b680e7afc78727e21aff3 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Sun, 29 Jul 2018 15:51:48 -0400 Subject: ext4: super: extend timestamps to 40 bits The inode timestamps use 34 bits in ext4, but the various timestamps in the superblock are limited to 32 bits. If every user accesses these as 'unsigned', then this is good until year 2106, but it seems better to extend this a bit further in the process of removing the deprecated get_seconds() function. This adds another byte for each timestamp in the superblock, making them long enough to store timestamps beyond what is in the inodes, which seems good enough here (in ocfs2, they are already 64-bit wide, which is appropriate for a new layout). I did not modify e2fsprogs, which obviously needs the same change to actually interpret future timestamps correctly. Signed-off-by: Arnd Bergmann Signed-off-by: Theodore Ts'o --- fs/ext4/sysfs.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'fs/ext4/sysfs.c') diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c index b970a200f20c..e60cc5e89023 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -25,6 +25,8 @@ typedef enum { attr_reserved_clusters, attr_inode_readahead, attr_trigger_test_error, + attr_first_error_time, + attr_last_error_time, attr_feature, attr_pointer_ui, attr_pointer_atomic, @@ -182,8 +184,8 @@ EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst); EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval); EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst); EXT4_RO_ATTR_ES_UI(errors_count, s_error_count); -EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time); -EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time); +EXT4_ATTR(first_error_time, 0444, first_error_time); +EXT4_ATTR(last_error_time, 0444, last_error_time); static unsigned int old_bump_val = 128; EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val); @@ -249,6 +251,15 @@ static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi) return NULL; } +static ssize_t __print_tstamp(char *buf, __le32 lo, __u8 hi) +{ + return snprintf(buf, PAGE_SIZE, "%lld", + ((time64_t)hi << 32) + le32_to_cpu(lo)); +} + +#define print_tstamp(buf, es, tstamp) \ + __print_tstamp(buf, (es)->tstamp, (es)->tstamp ## _hi) + static ssize_t ext4_attr_show(struct kobject *kobj, struct attribute *attr, char *buf) { @@ -287,6 +298,10 @@ static ssize_t ext4_attr_show(struct kobject *kobj, atomic_read((atomic_t *) ptr)); case attr_feature: return snprintf(buf, PAGE_SIZE, "supported\n"); + case attr_first_error_time: + return print_tstamp(buf, sbi->s_es, s_first_error_time); + case attr_last_error_time: + return print_tstamp(buf, sbi->s_es, s_last_error_time); } return 0; -- cgit v1.2.3