From: Ojaswin Mujoo ojaswin@linux.ibm.com
commit 27b38686a3bb601db48901dbc4e2fc5d77ffa2c1 upstream.
After moving to the new mount API, mb_optimize_scan mount option handling was not working as expected due to the parsed value always being overwritten by default. Refactor and fix this to the expected behavior described below:
* mb_optimize_scan=1 - On * mb_optimize_scan=0 - Off * mb_optimize_scan not passed - On if no. of BGs > threshold else off * Remounts retain previous value unless we explicitly pass the option with a new value
Fixes: cebe85d570cf ("ext4: switch to the new mount api") Cc: stable@kernel.org Reported-by: Ritesh Harjani riteshh@linux.ibm.com Signed-off-by: Ojaswin Mujoo ojaswin@linux.ibm.com Reviewed-by: Ritesh Harjani riteshh@linux.ibm.com Link: https://lore.kernel.org/r/c98970fe99f26718586d02e942f293300fb48ef3.164673269... Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/super.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-)
--- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2021,12 +2021,12 @@ static int ext4_set_test_dummy_encryptio #define EXT4_SPEC_s_commit_interval (1 << 16) #define EXT4_SPEC_s_fc_debug_max_replay (1 << 17) #define EXT4_SPEC_s_sb_block (1 << 18) +#define EXT4_SPEC_mb_optimize_scan (1 << 19)
struct ext4_fs_context { char *s_qf_names[EXT4_MAXQUOTAS]; char *test_dummy_enc_arg; int s_jquota_fmt; /* Format of quota to use */ - int mb_optimize_scan; #ifdef CONFIG_EXT4_DEBUG int s_fc_debug_max_replay; #endif @@ -2451,12 +2451,17 @@ static int ext4_parse_param(struct fs_co ctx_clear_mount_opt(ctx, m->mount_opt); return 0; case Opt_mb_optimize_scan: - if (result.int_32 != 0 && result.int_32 != 1) { + if (result.int_32 == 1) { + ctx_set_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN); + ctx->spec |= EXT4_SPEC_mb_optimize_scan; + } else if (result.int_32 == 0) { + ctx_clear_mount_opt2(ctx, EXT4_MOUNT2_MB_OPTIMIZE_SCAN); + ctx->spec |= EXT4_SPEC_mb_optimize_scan; + } else { ext4_msg(NULL, KERN_WARNING, "mb_optimize_scan should be set to 0 or 1."); return -EINVAL; } - ctx->mb_optimize_scan = result.int_32; return 0; }
@@ -4369,7 +4374,6 @@ static int __ext4_fill_super(struct fs_c
/* Set defaults for the variables that will be set during parsing */ ctx->journal_ioprio = DEFAULT_JOURNAL_IOPRIO; - ctx->mb_optimize_scan = DEFAULT_MB_OPTIMIZE_SCAN;
sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS; sbi->s_sectors_written_start = @@ -5320,12 +5324,12 @@ no_journal: * turned off by passing "mb_optimize_scan=0". This can also be * turned on forcefully by passing "mb_optimize_scan=1". */ - if (ctx->mb_optimize_scan == 1) - set_opt2(sb, MB_OPTIMIZE_SCAN); - else if (ctx->mb_optimize_scan == 0) - clear_opt2(sb, MB_OPTIMIZE_SCAN); - else if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD) - set_opt2(sb, MB_OPTIMIZE_SCAN); + if (!(ctx->spec & EXT4_SPEC_mb_optimize_scan)) { + if (sbi->s_groups_count >= MB_DEFAULT_LINEAR_SCAN_THRESHOLD) + set_opt2(sb, MB_OPTIMIZE_SCAN); + else + clear_opt2(sb, MB_OPTIMIZE_SCAN); + }
err = ext4_mb_init(sb); if (err) {