| Message ID | 502CC4BA.3040702@gmail.com |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Thu 16-08-12 12:00:26, Marco Stornelli wrote: > From: Marco Stornelli <marco.stornelli@gmail.com> > > Replaced lock and unlock super with a new fs mutex s_lock. Hum, is the lock needed at all? Remount & unfreeze both run with s_umount held for writing. Thus we already have exclusion between these two calls. The same seems to hold for ext4 BTW. Honza > > Signed-off-by: Marco Stornelli <marco.stornelli@gmail.com> > --- > > diff -Nurp linux-3.6-rc1-orig/fs/ext3/ext3.h linux-3.6-rc1/fs/ext3/ext3.h > --- linux-3.6-rc1-orig/fs/ext3/ext3.h 2012-08-16 09:37:31.000000000 +0200 > +++ linux-3.6-rc1/fs/ext3/ext3.h 2012-08-16 09:46:39.000000000 +0200 > @@ -672,6 +672,7 @@ struct ext3_sb_info { > char *s_qf_names[MAXQUOTAS]; /* Names of quota files with journalled quota */ > int s_jquota_fmt; /* Format of quota to use */ > #endif > + struct mutex s_lock; > }; > static inline spinlock_t * > diff -Nurp linux-3.6-rc1-orig/fs/ext3/super.c linux-3.6-rc1/fs/ext3/super.c > --- linux-3.6-rc1-orig/fs/ext3/super.c 2012-08-16 09:37:31.000000000 +0200 > +++ linux-3.6-rc1/fs/ext3/super.c 2012-08-16 09:49:11.000000000 +0200 > @@ -1939,6 +1939,7 @@ static int ext3_fill_super (struct super > sbi->s_gdb_count = db_count; > get_random_bytes(&sbi->s_next_generation, sizeof(u32)); > spin_lock_init(&sbi->s_next_gen_lock); > + mutex_init(&sbi->s_lock); > /* per fileystem reservation list head & lock */ > spin_lock_init(&sbi->s_rsv_window_lock); > @@ -2582,11 +2583,11 @@ out: > static int ext3_unfreeze(struct super_block *sb) > { > if (!(sb->s_flags & MS_RDONLY)) { > - lock_super(sb); > + mutex_lock(&EXT3_SB(sb)->s_lock); > /* Reser the needs_recovery flag before the fs is unlocked. */ > EXT3_SET_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER); > ext3_commit_super(sb, EXT3_SB(sb)->s_es, 1); > - unlock_super(sb); > + mutex_unlock(&EXT3_SB(sb)->s_lock); > journal_unlock_updates(EXT3_SB(sb)->s_journal); > } > return 0; > @@ -2606,7 +2607,7 @@ static int ext3_remount (struct super_bl > #endif > /* Store the original options */ > - lock_super(sb); > + mutex_lock(&EXT3_SB(sb)->s_lock); > old_sb_flags = sb->s_flags; > old_opts.s_mount_opt = sbi->s_mount_opt; > old_opts.s_resuid = sbi->s_resuid; > @@ -2712,7 +2713,7 @@ static int ext3_remount (struct super_bl > old_opts.s_qf_names[i] != sbi->s_qf_names[i]) > kfree(old_opts.s_qf_names[i]); > #endif > - unlock_super(sb); > + mutex_unlock(&EXT3_SB(sb)->s_lock); > if (enable_quota) > dquot_resume(sb, -1); > @@ -2732,7 +2733,7 @@ restore_opts: > sbi->s_qf_names[i] = old_opts.s_qf_names[i]; > } > #endif > - unlock_super(sb); > + mutex_unlock(&EXT3_SB(sb)->s_lock); > return err; > } >
On Thu, Aug 16, 2012 at 06:39:04PM +0200, Jan Kara wrote: > On Thu 16-08-12 12:00:26, Marco Stornelli wrote: > > From: Marco Stornelli <marco.stornelli@gmail.com> > > > > Replaced lock and unlock super with a new fs mutex s_lock. > Hum, is the lock needed at all? Remount & unfreeze both run with s_umount > held for writing. Thus we already have exclusion between these two calls. > The same seems to hold for ext4 BTW. Agreed, it's not clear lock_super() is needed at all for ext4 at this point. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Il 16/08/2012 21:19, Theodore Ts'o ha scritto: > On Thu, Aug 16, 2012 at 06:39:04PM +0200, Jan Kara wrote: >> On Thu 16-08-12 12:00:26, Marco Stornelli wrote: >>> From: Marco Stornelli <marco.stornelli@gmail.com> >>> >>> Replaced lock and unlock super with a new fs mutex s_lock. >> Hum, is the lock needed at all? Remount & unfreeze both run with s_umount >> held for writing. Thus we already have exclusion between these two calls. >> The same seems to hold for ext4 BTW. > > Agreed, it's not clear lock_super() is needed at all for ext4 at this > point. > > - Ted > Great. I'll remove the calls for ext3/ext4 when I'll submit the second version of the patch. Thanks for your feedback, Marco -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff -Nurp linux-3.6-rc1-orig/fs/ext3/ext3.h linux-3.6-rc1/fs/ext3/ext3.h --- linux-3.6-rc1-orig/fs/ext3/ext3.h 2012-08-16 09:37:31.000000000 +0200 +++ linux-3.6-rc1/fs/ext3/ext3.h 2012-08-16 09:46:39.000000000 +0200 @@ -672,6 +672,7 @@ struct ext3_sb_info { char *s_qf_names[MAXQUOTAS]; /* Names of quota files with journalled quota */ int s_jquota_fmt; /* Format of quota to use */ #endif + struct mutex s_lock; }; static inline spinlock_t * diff -Nurp linux-3.6-rc1-orig/fs/ext3/super.c linux-3.6-rc1/fs/ext3/super.c --- linux-3.6-rc1-orig/fs/ext3/super.c 2012-08-16 09:37:31.000000000 +0200 +++ linux-3.6-rc1/fs/ext3/super.c 2012-08-16 09:49:11.000000000 +0200 @@ -1939,6 +1939,7 @@ static int ext3_fill_super (struct super sbi->s_gdb_count = db_count; get_random_bytes(&sbi->s_next_generation, sizeof(u32)); spin_lock_init(&sbi->s_next_gen_lock); + mutex_init(&sbi->s_lock); /* per fileystem reservation list head & lock */ spin_lock_init(&sbi->s_rsv_window_lock); @@ -2582,11 +2583,11 @@ out: