From 32ed5058ce90024efcd811254b4b1de0468099df Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sat, 25 Apr 2009 22:53:39 -0400 Subject: ext4: Replace lock/unlock_super() with an explicit lock for resizing Use a separate lock to protect s_groups_count and the other block group descriptors which get changed via an on-line resize operation, so we can stop overloading the use of lock_super(). Signed-off-by: "Theodore Ts'o" --- fs/ext4/resize.c | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-) (limited to 'fs/ext4/resize.c') diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index 546c7dd869e..e8ded13b5cb 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -193,7 +193,7 @@ static int setup_new_group_blocks(struct super_block *sb, if (IS_ERR(handle)) return PTR_ERR(handle); - lock_super(sb); + mutex_lock(&sbi->s_resize_lock); if (input->group != sbi->s_groups_count) { err = -EBUSY; goto exit_journal; @@ -302,7 +302,7 @@ exit_bh: brelse(bh); exit_journal: - unlock_super(sb); + mutex_unlock(&sbi->s_resize_lock); if ((err2 = ext4_journal_stop(handle)) && !err) err = err2; @@ -643,11 +643,12 @@ exit_free: * important part is that the new block and inode counts are in the backup * superblocks, and the location of the new group metadata in the GDT backups. * - * We do not need lock_super() for this, because these blocks are not - * otherwise touched by the filesystem code when it is mounted. We don't - * need to worry about last changing from sbi->s_groups_count, because the - * worst that can happen is that we do not copy the full number of backups - * at this time. The resize which changed s_groups_count will backup again. + * We do not need take the s_resize_lock for this, because these + * blocks are not otherwise touched by the filesystem code when it is + * mounted. We don't need to worry about last changing from + * sbi->s_groups_count, because the worst that can happen is that we + * do not copy the full number of backups at this time. The resize + * which changed s_groups_count will backup again. */ static void update_backups(struct super_block *sb, int blk_off, char *data, int size) @@ -809,7 +810,7 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) goto exit_put; } - lock_super(sb); + mutex_lock(&sbi->s_resize_lock); if (input->group != sbi->s_groups_count) { ext4_warning(sb, __func__, "multiple resizers run on filesystem!"); @@ -840,7 +841,7 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) /* * OK, now we've set up the new group. Time to make it active. * - * Current kernels don't lock all allocations via lock_super(), + * We do not lock all allocations via s_resize_lock * so we have to be safe wrt. concurrent accesses the group * data. So we need to be careful to set all of the relevant * group descriptor data etc. *before* we enable the group. @@ -900,12 +901,12 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) * * The precise rules we use are: * - * * Writers of s_groups_count *must* hold lock_super + * * Writers of s_groups_count *must* hold s_resize_lock * AND * * Writers must perform a smp_wmb() after updating all dependent * data and before modifying the groups count * - * * Readers must hold lock_super() over the access + * * Readers must hold s_resize_lock over the access * OR * * Readers must perform an smp_rmb() after reading the groups count * and before reading any dependent data. @@ -948,7 +949,7 @@ int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) sb->s_dirt = 1; exit_journal: - unlock_super(sb); + mutex_unlock(&sbi->s_resize_lock); if ((err2 = ext4_journal_stop(handle)) && !err) err = err2; if (!err) { @@ -986,7 +987,7 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es, /* We don't need to worry about locking wrt other resizers just * yet: we're going to revalidate es->s_blocks_count after - * taking lock_super() below. */ + * taking the s_resize_lock below. */ o_blocks_count = ext4_blocks_count(es); o_groups_count = EXT4_SB(sb)->s_groups_count; @@ -1056,11 +1057,11 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es, goto exit_put; } - lock_super(sb); + mutex_lock(&EXT4_SB(sb)->s_resize_lock); if (o_blocks_count != ext4_blocks_count(es)) { ext4_warning(sb, __func__, "multiple resizers run on filesystem!"); - unlock_super(sb); + mutex_unlock(&EXT4_SB(sb)->s_resize_lock); ext4_journal_stop(handle); err = -EBUSY; goto exit_put; @@ -1070,14 +1071,14 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es, EXT4_SB(sb)->s_sbh))) { ext4_warning(sb, __func__, "error %d on journal write access", err); - unlock_super(sb); + mutex_unlock(&EXT4_SB(sb)->s_resize_lock); ext4_journal_stop(handle); goto exit_put; } ext4_blocks_count_set(es, o_blocks_count + add); ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); sb->s_dirt = 1; - unlock_super(sb); + mutex_unlock(&EXT4_SB(sb)->s_resize_lock); ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count, o_blocks_count + add); /* We add the blocks to the bitmap and set the group need init bit */ -- cgit v1.2.3-70-g09d2 From bb23c20a851a5038b255a3c0d0aa56093c1da3f8 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Fri, 1 May 2009 19:44:44 -0400 Subject: ext4: Move fs/ext4/group.h into ext4.h Move the function prototypes in group.h into ext4.h so they are all defined in one place. Signed-off-by: "Theodore Ts'o" --- fs/ext4/balloc.c | 1 - fs/ext4/ext4.h | 17 +++++++++++++++++ fs/ext4/group.h | 29 ----------------------------- fs/ext4/ialloc.c | 1 - fs/ext4/mballoc.h | 1 - fs/ext4/resize.c | 1 - fs/ext4/super.c | 1 - 7 files changed, 17 insertions(+), 34 deletions(-) delete mode 100644 fs/ext4/group.h (limited to 'fs/ext4/resize.c') diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index a5ba039850c..92f557d957d 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -19,7 +19,6 @@ #include #include "ext4.h" #include "ext4_jbd2.h" -#include "group.h" #include "mballoc.h" /* diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index d9c5251d082..5973f3261b0 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1270,6 +1270,14 @@ extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb, ext4_group_t block_group, struct buffer_head ** bh); extern int ext4_should_retry_alloc(struct super_block *sb, int *retries); +struct buffer_head *ext4_read_block_bitmap(struct super_block *sb, + ext4_group_t block_group); +extern unsigned ext4_init_block_bitmap(struct super_block *sb, + struct buffer_head *bh, + ext4_group_t group, + struct ext4_group_desc *desc); +#define ext4_free_blocks_after_init(sb, group, desc) \ + ext4_init_block_bitmap(sb, NULL, group, desc) /* dir.c */ extern int ext4_check_dir_entry(const char *, struct inode *, @@ -1294,6 +1302,11 @@ extern struct inode * ext4_orphan_get(struct super_block *, unsigned long); extern unsigned long ext4_count_free_inodes(struct super_block *); extern unsigned long ext4_count_dirs(struct super_block *); extern void ext4_check_inodes_bitmap(struct super_block *); +extern unsigned ext4_init_inode_bitmap(struct super_block *sb, + struct buffer_head *bh, + ext4_group_t group, + struct ext4_group_desc *desc); +extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap); /* mballoc.c */ extern long ext4_mb_stats; @@ -1417,6 +1430,10 @@ extern void ext4_used_dirs_set(struct super_block *sb, struct ext4_group_desc *bg, __u32 count); extern void ext4_itable_unused_set(struct super_block *sb, struct ext4_group_desc *bg, __u32 count); +extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group, + struct ext4_group_desc *gdp); +extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group, + struct ext4_group_desc *gdp); static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es) { diff --git a/fs/ext4/group.h b/fs/ext4/group.h deleted file mode 100644 index c2c0a8d06d0..00000000000 --- a/fs/ext4/group.h +++ /dev/null @@ -1,29 +0,0 @@ -/* - * linux/fs/ext4/group.h - * - * Copyright (C) 2007 Cluster File Systems, Inc - * - * Author: Andreas Dilger - */ - -#ifndef _LINUX_EXT4_GROUP_H -#define _LINUX_EXT4_GROUP_H - -extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group, - struct ext4_group_desc *gdp); -extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group, - struct ext4_group_desc *gdp); -struct buffer_head *ext4_read_block_bitmap(struct super_block *sb, - ext4_group_t block_group); -extern unsigned ext4_init_block_bitmap(struct super_block *sb, - struct buffer_head *bh, - ext4_group_t group, - struct ext4_group_desc *desc); -#define ext4_free_blocks_after_init(sb, group, desc) \ - ext4_init_block_bitmap(sb, NULL, group, desc) -extern unsigned ext4_init_inode_bitmap(struct super_block *sb, - struct buffer_head *bh, - ext4_group_t group, - struct ext4_group_desc *desc); -extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap); -#endif /* _LINUX_EXT4_GROUP_H */ diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 55ba419ca00..916d05c881c 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -27,7 +27,6 @@ #include "ext4_jbd2.h" #include "xattr.h" #include "acl.h" -#include "group.h" /* * ialloc.c contains the inodes allocation and deallocation routines diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h index dd9e6cd5f6c..75e34f69215 100644 --- a/fs/ext4/mballoc.h +++ b/fs/ext4/mballoc.h @@ -23,7 +23,6 @@ #include #include "ext4_jbd2.h" #include "ext4.h" -#include "group.h" /* * with AGGRESSIVE_CHECK allocator runs consistency checks over diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c index e8ded13b5cb..27eb289eea3 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -15,7 +15,6 @@ #include #include "ext4_jbd2.h" -#include "group.h" #define outside(b, first, last) ((b) < (first) || (b) >= (last)) #define inside(b, first, last) ((b) >= (first) && (b) < (last)) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index d79e1c428b4..7903f20c807 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -46,7 +46,6 @@ #include "ext4_jbd2.h" #include "xattr.h" #include "acl.h" -#include "group.h" struct proc_dir_entry *ext4_proc_root; static struct kset *ext4_kset; -- cgit v1.2.3-70-g09d2