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| author | Baokun Li <libaokun1@huawei.com> | 2024-03-19 19:33:21 +0800 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2024-05-02 23:48:30 -0400 |
| commit | b7b2a5799b8fafe95fcd5455c32ba2c643c86f99 (patch) | |
| tree | ace7ef46cfc467b8f08b699aaf0649236a09d559 | |
| parent | 13df4d44a3aaabe61cd01d277b6ee23ead2a5206 (diff) | |
| download | lwn-b7b2a5799b8fafe95fcd5455c32ba2c643c86f99.tar.gz lwn-b7b2a5799b8fafe95fcd5455c32ba2c643c86f99.zip | |
ext4: add new attr pointer attr_mb_order
The s_mb_best_avail_max_trim_order is of type unsigned int, and has a
range of values well beyond the normal use of the mb_order. Although the
mballoc code is careful enough that large numbers don't matter there, but
this can mislead the sysadmin into thinking that it's normal to set such
values. Hence add a new attr_id attr_mb_order with values in the range
[0, 64] to avoid storing garbage values and make us more resilient to
surprises in the future.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240319113325.3110393-6-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | fs/ext4/sysfs.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c index ddd71673176c..8e0473169458 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -30,6 +30,7 @@ typedef enum { attr_first_error_time, attr_last_error_time, attr_clusters_in_group, + attr_mb_order, attr_feature, attr_pointer_ui, attr_pointer_ul, @@ -210,6 +211,8 @@ EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead, ext4_sb_info, s_inode_readahead_blks); EXT4_ATTR_OFFSET(mb_group_prealloc, 0644, clusters_in_group, ext4_sb_info, s_mb_group_prealloc); +EXT4_ATTR_OFFSET(mb_best_avail_max_trim_order, 0644, mb_order, + ext4_sb_info, s_mb_best_avail_max_trim_order); EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal); EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats); EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan); @@ -225,7 +228,6 @@ EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.int 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_RW_ATTR_SBI_UI(mb_best_avail_max_trim_order, s_mb_best_avail_max_trim_order); #ifdef CONFIG_EXT4_DEBUG EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail); #endif @@ -379,6 +381,7 @@ static ssize_t ext4_generic_attr_show(struct ext4_attr *a, switch (a->attr_id) { case attr_inode_readahead: case attr_clusters_in_group: + case attr_mb_order: case attr_pointer_ui: if (a->attr_ptr == ptr_ext4_super_block_offset) return sysfs_emit(buf, "%u\n", le32_to_cpup(ptr)); @@ -458,6 +461,14 @@ static ssize_t ext4_generic_attr_store(struct ext4_attr *a, else *((unsigned int *) ptr) = t; return len; + case attr_mb_order: + ret = kstrtouint(skip_spaces(buf), 0, &t); + if (ret) + return ret; + if (t > 64) + return -EINVAL; + *((unsigned int *) ptr) = t; + return len; case attr_clusters_in_group: ret = kstrtouint(skip_spaces(buf), 0, &t); if (ret) |