From: Frederic Bohe <frederic.bohe@xxxxxxxx>
Update group infos when updating a group's descriptor.
Add group infos when adding a group's descriptor.
Refresh cache pages used by mb_alloc when changes occur.
Signed-off-by: Frederic Bohe <frederic.bohe@xxxxxxxx>
---
This patch apply on top of 2.6.26-rc6 + ext4-patch-queue-37b3e39765d8521ba2252bfec81bb91504fa35c8
It fixes oops when a filesystem is resized online while being mounted with mballoc.
Two oops have been identified:
The first one occurs when unmounting the resized filesystem.
The second one happens when trying to write to a group added during the online resize.
This patch has been tested with:
- small (100MB) and large (5TB) filesystems.
- 1K blocks and 4K blocks filesystems.
- inode size=256 up to 1024.
Tests consist in :
- online resizing, filling all blocks of the fs, unmounting, fs check
- filling all blocks of the fs, online resizing, filling newly added groups, unmounting, fs check
- Concurrent file copy/online resize, unmounting, fs check.
Non regression tests :
- offline resizing.
- online resizing without mballoc.
ext4.h | 4 +
mballoc.c | 207 ++++++++++++++++++++++++++++++++++++++++++++++----------------
resize.c | 40 +++++++++++
3 files changed, 199 insertions(+), 52 deletions(-)
Index: linux-2.6.26-rc6.patch_resize/fs/ext4/ext4.h
===================================================================
--- linux-2.6.26-rc6.patch_resize.orig/fs/ext4/ext4.h 2008-06-25 11:08:43.000000000 +0200
+++ linux-2.6.26-rc6.patch_resize/fs/ext4/ext4.h 2008-06-25 11:09:38.000000000 +0200
@@ -1115,6 +1115,10 @@ extern int __init init_ext4_mballoc(void
extern void exit_ext4_mballoc(void);
extern void ext4_mb_free_blocks(handle_t *, struct inode *,
unsigned long, unsigned long, int, unsigned long *);
+extern int ext4_mb_add_more_groupinfo(struct super_block *sb,
+ ext4_group_t i, struct ext4_group_desc *desc);
+extern void ext4_mb_update_group_info(struct ext4_group_info *grp,
+ ext4_grpblk_t add);
/* inode.c */
Index: linux-2.6.26-rc6.patch_resize/fs/ext4/mballoc.c
===================================================================
--- linux-2.6.26-rc6.patch_resize.orig/fs/ext4/mballoc.c 2008-06-25 11:09:30.000000000 +0200
+++ linux-2.6.26-rc6.patch_resize/fs/ext4/mballoc.c 2008-06-26 14:43:31.000000000 +0200
@@ -2235,21 +2235,176 @@ ext4_mb_store_history(struct ext4_alloca
#define ext4_mb_history_init(sb)
#endif
+
+/* Create and initialize ext4_group_info data */
+/* for the given group. */
+
+int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
+struct ext4_group_desc *desc)
+{
+ int i, len;
+ int metalen = 0;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_group_info **meta_group_info;
+
+ /* First check if this group is the first of a reserved block.
+ * If it's true, we have to allocate a new table of pointers
+ * to ext4_group_info structures
+ */
+ if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
+ metalen = sizeof(*meta_group_info)
+ << EXT4_DESC_PER_BLOCK_BITS(sb);
+ meta_group_info = kmalloc(metalen, GFP_KERNEL);
+ if (meta_group_info == NULL) {
+ printk(KERN_ERR "EXT4-fs: can't allocate mem for a "
+ "buddy group\n");
+ goto exit_meta_group_info;
+ }
+ sbi->s_group_info[group >>
+ EXT4_DESC_PER_BLOCK_BITS(sb)] = meta_group_info;
+ }
+
+ /*
+ * calculate needed size. if change bb_counters size,
+ * don't forget about ext4_mb_generate_buddy()
+ */
+ len = sizeof(struct ext4_group_info);
+ len += sizeof(unsigned short) * (sb->s_blocksize_bits + 2);
+
+ meta_group_info =
+ sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)];
+ i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
+
+ meta_group_info[i] = kzalloc(len, GFP_KERNEL);
+ if (meta_group_info[i] == NULL) {
+ printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n");
+ goto exit_group_info;
+ }
+ set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
+ &(meta_group_info[i]->bb_state));
+
+ /*
+ * initialize bb_free to be able to skip
+ * empty groups without initialization
+ */
+ if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
+ meta_group_info[i]->bb_free =
+ ext4_free_blocks_after_init(sb, group, desc);
+ } else {
+ meta_group_info[i]->bb_free =
+ le16_to_cpu(desc->bg_free_blocks_count);
+ }
+
+ INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
+
+#ifdef DOUBLE_CHECK
+ {
+ struct buffer_head *bh;
+ meta_group_info[i]->bb_bitmap =
+ kmalloc(sb->s_blocksize, GFP_KERNEL);
+ BUG_ON(meta_group_info[i]->bb_bitmap == NULL);
+ bh = ext4_read_block_bitmap(sb, group);
+ BUG_ON(bh == NULL);
+ memcpy(meta_group_info[i]->bb_bitmap, bh->b_data,
+ sb->s_blocksize);
+ put_bh(bh);
+ }
+#endif
+
+ return 0;
+exit_group_info:
+ /* If a meta_group_info table has been allocated, release it now */
+ if (group % EXT4_DESC_PER_BLOCK(sb) == 0)
+ kfree(sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)]);
+exit_meta_group_info:
+ return -ENOMEM;
+} /* ext4_mb_add_groupinfo */
+
+/* Add a group to the existing groups.
+ * This function is used for online resize
+ */
+int ext4_mb_add_more_groupinfo(struct super_block *sb, ext4_group_t group,
+ struct ext4_group_desc *desc)
+{
+ struct inode *inode = EXT4_SB(sb)->s_buddy_cache;
+ int blocks_per_page;
+ int block;
+ int pnum;
+ struct page *page;
+ int err;
+
+ /* Add group based on group descriptor*/
+ err = ext4_mb_add_groupinfo(sb, group, desc);
+ if (err)
+ return err;
+
+ /* Cache pages containing dynamic mb_alloc datas (buddy and bitmap
+ * datas) are set not up to date so that they will be re-initilaized
+ * during the next call to ext4_mb_load_buddy
+ */
+
+ /* Set buddy page as not up to date */
+ blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
+ block = group * 2;
+ pnum = block / blocks_per_page;
+ page = find_get_page(inode->i_mapping, pnum);
+ if (page != NULL) {
+ ClearPageUptodate(page);
+ page_cache_release(page);
+ }
+
+ /* Set bitmap page as not up to date */
+ block++;
+ pnum = block / blocks_per_page;
+ page = find_get_page(inode->i_mapping, pnum);
+ if (page != NULL) {
+ ClearPageUptodate(page);
+ page_cache_release(page);
+ }
+
+ return 0;
+}
+
+/* Update an existing group.
+ * This function is used for online resize
+ */
+void ext4_mb_update_group_info(struct ext4_group_info *grp, ext4_grpblk_t add)
+{
+ grp->bb_free += add;
+}
+
static int ext4_mb_init_backend(struct super_block *sb)
{
ext4_group_t i;
- int j, len, metalen;
+ int metalen;
struct ext4_sb_info *sbi = EXT4_SB(sb);
- int num_meta_group_infos =
- (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) >>
- EXT4_DESC_PER_BLOCK_BITS(sb);
+ struct ext4_super_block *es = sbi->s_es;
+ int num_meta_group_infos;
+ int num_meta_group_infos_max;
struct ext4_group_info **meta_group_info;
+ struct ext4_group_desc *desc;
+
+ /* This is the number of blocks used by GDT */
+ num_meta_group_infos = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) -
+ 1) >> EXT4_DESC_PER_BLOCK_BITS(sb);
+
+ /* This is the total number of blocks used by GDT including
+ * the number of reserved blocks for GDT.
+ * The s_group_info array is allocated with this value
+ * to allow a clean online resize without a complex
+ * manipulation of pointer.
+ * The drawback is the unused memory when no resize
+ * occurs but it's very low in terms of pages
+ * (see comments below)
+ */
+ num_meta_group_infos_max = num_meta_group_infos +
+ le16_to_cpu(es->s_reserved_gdt_blocks);
/* An 8TB filesystem with 64-bit pointers requires a 4096 byte
* kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
* So a two level scheme suffices for now. */
sbi->s_group_info = kmalloc(sizeof(*sbi->s_group_info) *
- num_meta_group_infos, GFP_KERNEL);
+ num_meta_group_infos_max, GFP_KERNEL);
if (sbi->s_group_info == NULL) {
printk(KERN_ERR "EXT4-fs: can't allocate buddy meta group\n");
return -ENOMEM;
@@ -2276,62 +2431,15 @@ static int ext4_mb_init_backend(struct s
sbi->s_group_info[i] = meta_group_info;
}
- /*
- * calculate needed size. if change bb_counters size,
- * don't forget about ext4_mb_generate_buddy()
- */
- len = sizeof(struct ext4_group_info);
- len += sizeof(unsigned short) * (sb->s_blocksize_bits + 2);
for (i = 0; i < sbi->s_groups_count; i++) {
- struct ext4_group_desc *desc;
-
- meta_group_info =
- sbi->s_group_info[i >> EXT4_DESC_PER_BLOCK_BITS(sb)];
- j = i & (EXT4_DESC_PER_BLOCK(sb) - 1);
-
- meta_group_info[j] = kzalloc(len, GFP_KERNEL);
- if (meta_group_info[j] == NULL) {
- printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n");
- goto err_freebuddy;
- }
desc = ext4_get_group_desc(sb, i, NULL);
if (desc == NULL) {
printk(KERN_ERR
"EXT4-fs: can't read descriptor %lu\n", i);
- i++;
goto err_freebuddy;
}
- set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
- &(meta_group_info[j]->bb_state));
-
- /*
- * initialize bb_free to be able to skip
- * empty groups without initialization
- */
- if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
- meta_group_info[j]->bb_free =
- ext4_free_blocks_after_init(sb, i, desc);
- } else {
- meta_group_info[j]->bb_free =
- le16_to_cpu(desc->bg_free_blocks_count);
- }
-
- INIT_LIST_HEAD(&meta_group_info[j]->bb_prealloc_list);
-
-#ifdef DOUBLE_CHECK
- {
- struct buffer_head *bh;
- meta_group_info[j]->bb_bitmap =
- kmalloc(sb->s_blocksize, GFP_KERNEL);
- BUG_ON(meta_group_info[j]->bb_bitmap == NULL);
- bh = ext4_read_block_bitmap(sb, i);
- BUG_ON(bh == NULL);
- memcpy(meta_group_info[j]->bb_bitmap, bh->b_data,
- sb->s_blocksize);
- put_bh(bh);
- }
-#endif
-
+ if (ext4_mb_add_groupinfo(sb, i, desc) != 0)
+ goto err_freebuddy;
}
return 0;
Index: linux-2.6.26-rc6.patch_resize/fs/ext4/resize.c
===================================================================
--- linux-2.6.26-rc6.patch_resize.orig/fs/ext4/resize.c 2008-06-25 11:08:43.000000000 +0200
+++ linux-2.6.26-rc6.patch_resize/fs/ext4/resize.c 2008-06-26 14:44:32.000000000 +0200
@@ -865,6 +865,13 @@ int ext4_group_add(struct super_block *s
gdp->bg_free_inodes_count = cpu_to_le16(EXT4_INODES_PER_GROUP(sb));
gdp->bg_checksum = ext4_group_desc_csum(sbi, input->group, gdp);
+ /* We can allocate memory for mb_alloc based on the new group
+ * descriptor */
+ if (test_opt(sb, MBALLOC)) {
+ err = ext4_mb_add_more_groupinfo(sb, input->group, gdp);
+ if (err)
+ goto exit_journal;
+ }
/*
* Make the new blocks and inodes valid next. We do this before
* increasing the group count so that once the group is enabled,
@@ -957,6 +964,8 @@ int ext4_group_extend(struct super_block
handle_t *handle;
int err;
unsigned long freed_blocks;
+ ext4_group_t group;
+ struct ext4_group_info *grp;
/* We don't need to worry about locking wrt other resizers just
* yet: we're going to revalidate es->s_blocks_count after
@@ -988,7 +997,7 @@ int ext4_group_extend(struct super_block
}
/* Handle the remaining blocks in the last group only. */
- ext4_get_group_no_and_offset(sb, o_blocks_count, NULL, &last);
+ ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last);
if (last == 0) {
ext4_warning(sb, __func__,
@@ -1060,6 +1069,43 @@ int ext4_group_extend(struct super_block
o_blocks_count + add);
if ((err = ext4_journal_stop(handle)))
goto exit_put;
+
+ /* Mark mballoc pages as not up to date so that they will be updated
+ * next time they are loaded by ext4_mb_load_buddy.
+ */
+ if (test_opt(sb, MBALLOC)) {
+ struct inode *inode = EXT4_SB(sb)->s_buddy_cache;
+ int blocks_per_page;
+ int block;
+ int pnum;
+ struct page *page;
+
+ /* Set buddy page as not up to date */
+ blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
+ block = group * 2;
+ pnum = block / blocks_per_page;
+ page = find_get_page(inode->i_mapping, pnum);
+ if (page != NULL) {
+ ClearPageUptodate(page);
+ page_cache_release(page);
+ }
+
+ /* Set bitmap page as not up to date */
+ block++;
+ pnum = block / blocks_per_page;
+ page = find_get_page(inode->i_mapping, pnum);
+ if (page != NULL) {
+ ClearPageUptodate(page);
+ page_cache_release(page);
+ }
+
+ /* Get the info on the last group */
+ grp = ext4_get_group_info(sb, group);
+
+ /* Update free blocks in group info */
+ ext4_mb_update_group_info(grp, add);
+ }
+
if (test_opt(sb, DEBUG))
printk(KERN_DEBUG "EXT4-fs: extended group to %llu blocks\n",
ext4_blocks_count(es));
--
--
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