ext4: fold ext4_claim_inode into ext4_new_inode
The function ext4_claim_inode() is only called by one function, ext4_new_inode(), and by folding the functionality into ext4_new_inode(), we can remove almost 50 lines of code, and put all of the logic of allocating a new inode into a single place. Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Theodore Ts'o
Родитель
62aa2b537c
Коммит
119c0d4460
209
fs/ext4/ialloc.c
209
fs/ext4/ialloc.c
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@ -592,94 +592,6 @@ static int find_group_other(struct super_block *sb, struct inode *parent,
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return -1;
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}
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/*
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* claim the inode from the inode bitmap. If the group
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* is uninit we need to take the groups's ext4_group_lock
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* and clear the uninit flag. The inode bitmap update
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* and group desc uninit flag clear should be done
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* after holding ext4_group_lock so that ext4_read_inode_bitmap
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* doesn't race with the ext4_claim_inode
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*/
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static int ext4_claim_inode(struct super_block *sb,
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struct buffer_head *inode_bitmap_bh,
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unsigned long ino, ext4_group_t group, umode_t mode)
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{
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int free = 0, retval = 0, count;
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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struct ext4_group_info *grp = ext4_get_group_info(sb, group);
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struct ext4_group_desc *gdp = ext4_get_group_desc(sb, group, NULL);
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/*
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* We have to be sure that new inode allocation does not race with
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* inode table initialization, because otherwise we may end up
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* allocating and writing new inode right before sb_issue_zeroout
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* takes place and overwriting our new inode with zeroes. So we
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* take alloc_sem to prevent it.
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*/
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down_read(&grp->alloc_sem);
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ext4_lock_group(sb, group);
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if (ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data)) {
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/* not a free inode */
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retval = 1;
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goto err_ret;
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}
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ino++;
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if ((group == 0 && ino < EXT4_FIRST_INO(sb)) ||
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ino > EXT4_INODES_PER_GROUP(sb)) {
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ext4_unlock_group(sb, group);
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up_read(&grp->alloc_sem);
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ext4_error(sb, "reserved inode or inode > inodes count - "
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"block_group = %u, inode=%lu", group,
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ino + group * EXT4_INODES_PER_GROUP(sb));
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return 1;
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}
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/* If we didn't allocate from within the initialized part of the inode
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* table then we need to initialize up to this inode. */
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if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
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if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
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gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
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/* When marking the block group with
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* ~EXT4_BG_INODE_UNINIT we don't want to depend
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* on the value of bg_itable_unused even though
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* mke2fs could have initialized the same for us.
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* Instead we calculated the value below
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*/
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free = 0;
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} else {
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free = EXT4_INODES_PER_GROUP(sb) -
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ext4_itable_unused_count(sb, gdp);
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}
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/*
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* Check the relative inode number against the last used
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* relative inode number in this group. if it is greater
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* we need to update the bg_itable_unused count
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*
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*/
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if (ino > free)
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ext4_itable_unused_set(sb, gdp,
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(EXT4_INODES_PER_GROUP(sb) - ino));
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}
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count = ext4_free_inodes_count(sb, gdp) - 1;
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ext4_free_inodes_set(sb, gdp, count);
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if (S_ISDIR(mode)) {
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count = ext4_used_dirs_count(sb, gdp) + 1;
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ext4_used_dirs_set(sb, gdp, count);
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if (sbi->s_log_groups_per_flex) {
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ext4_group_t f = ext4_flex_group(sbi, group);
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atomic_inc(&sbi->s_flex_groups[f].used_dirs);
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}
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}
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gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
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err_ret:
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ext4_unlock_group(sb, group);
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up_read(&grp->alloc_sem);
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return retval;
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}
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/*
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* There are two policies for allocating an inode. If the new inode is
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* a directory, then a forward search is made for a block group with both
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@ -741,6 +653,11 @@ got_group:
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if (ret2 == -1)
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goto out;
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/*
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* Normally we will only go through one pass of this loop,
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* unless we get unlucky and it turns out the group we selected
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* had its last inode grabbed by someone else.
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*/
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for (i = 0; i < ngroups; i++, ino = 0) {
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err = -EIO;
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@ -757,51 +674,24 @@ repeat_in_this_group:
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ino = ext4_find_next_zero_bit((unsigned long *)
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inode_bitmap_bh->b_data,
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EXT4_INODES_PER_GROUP(sb), ino);
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if (ino < EXT4_INODES_PER_GROUP(sb)) {
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BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
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err = ext4_journal_get_write_access(handle,
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inode_bitmap_bh);
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if (err)
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goto fail;
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BUFFER_TRACE(group_desc_bh, "get_write_access");
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err = ext4_journal_get_write_access(handle,
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group_desc_bh);
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if (err)
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goto fail;
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if (!ext4_claim_inode(sb, inode_bitmap_bh,
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ino, group, mode)) {
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/* we won it */
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BUFFER_TRACE(inode_bitmap_bh,
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"call ext4_handle_dirty_metadata");
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err = ext4_handle_dirty_metadata(handle,
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NULL,
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inode_bitmap_bh);
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if (err)
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goto fail;
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/* zero bit is inode number 1*/
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ino++;
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goto got;
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}
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/* we lost it */
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ext4_handle_release_buffer(handle, inode_bitmap_bh);
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ext4_handle_release_buffer(handle, group_desc_bh);
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if (++ino < EXT4_INODES_PER_GROUP(sb))
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goto repeat_in_this_group;
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if (ino >= EXT4_INODES_PER_GROUP(sb)) {
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if (++group == ngroups)
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group = 0;
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continue;
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}
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/*
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* This case is possible in concurrent environment. It is very
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* rare. We cannot repeat the find_group_xxx() call because
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* that will simply return the same blockgroup, because the
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* group descriptor metadata has not yet been updated.
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* So we just go onto the next blockgroup.
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*/
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if (++group == ngroups)
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group = 0;
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if (group == 0 && (ino+1) < EXT4_FIRST_INO(sb)) {
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ext4_error(sb, "reserved inode found cleared - "
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"inode=%lu", ino + 1);
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continue;
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}
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ext4_lock_group(sb, group);
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ret2 = ext4_test_and_set_bit(ino, inode_bitmap_bh->b_data);
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ext4_unlock_group(sb, group);
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ino++; /* the inode bitmap is zero-based */
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if (!ret2)
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goto got; /* we grabbed the inode! */
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if (ino < EXT4_INODES_PER_GROUP(sb))
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goto repeat_in_this_group;
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}
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err = -ENOSPC;
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goto out;
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@ -838,6 +728,59 @@ got:
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if (err)
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goto fail;
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}
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BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
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err = ext4_journal_get_write_access(handle, inode_bitmap_bh);
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if (err)
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goto fail;
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BUFFER_TRACE(group_desc_bh, "get_write_access");
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err = ext4_journal_get_write_access(handle, group_desc_bh);
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if (err)
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goto fail;
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/* Update the relevant bg descriptor fields */
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if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
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int free;
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struct ext4_group_info *grp = ext4_get_group_info(sb, group);
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down_read(&grp->alloc_sem); /* protect vs itable lazyinit */
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ext4_lock_group(sb, group); /* while we modify the bg desc */
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free = EXT4_INODES_PER_GROUP(sb) -
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ext4_itable_unused_count(sb, gdp);
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if (gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
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gdp->bg_flags &= cpu_to_le16(~EXT4_BG_INODE_UNINIT);
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free = 0;
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}
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/*
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* Check the relative inode number against the last used
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* relative inode number in this group. if it is greater
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* we need to update the bg_itable_unused count
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*/
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if (ino > free)
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ext4_itable_unused_set(sb, gdp,
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(EXT4_INODES_PER_GROUP(sb) - ino));
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up_read(&grp->alloc_sem);
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}
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ext4_free_inodes_set(sb, gdp, ext4_free_inodes_count(sb, gdp) - 1);
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if (S_ISDIR(mode)) {
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ext4_used_dirs_set(sb, gdp, ext4_used_dirs_count(sb, gdp) + 1);
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if (sbi->s_log_groups_per_flex) {
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ext4_group_t f = ext4_flex_group(sbi, group);
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atomic_inc(&sbi->s_flex_groups[f].used_dirs);
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}
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}
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if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
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gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
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ext4_unlock_group(sb, group);
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}
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BUFFER_TRACE(inode_bitmap_bh, "call ext4_handle_dirty_metadata");
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err = ext4_handle_dirty_metadata(handle, NULL, inode_bitmap_bh);
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if (err)
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goto fail;
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BUFFER_TRACE(group_desc_bh, "call ext4_handle_dirty_metadata");
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err = ext4_handle_dirty_metadata(handle, NULL, group_desc_bh);
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if (err)
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@ -1101,7 +1044,7 @@ unsigned long ext4_count_dirs(struct super_block * sb)
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* where it is called from on active part of filesystem is ext4lazyinit
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* thread, so we do not need any special locks, however we have to prevent
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* inode allocation from the current group, so we take alloc_sem lock, to
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* block ext4_claim_inode until we are finished.
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* block ext4_new_inode() until we are finished.
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*/
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int ext4_init_inode_table(struct super_block *sb, ext4_group_t group,
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int barrier)
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