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Date: Tue, 25 Nov 2008 22:03:16 +0530
From: "Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
To: cmm@...ibm.com, tytso@....edu, sandeen@...hat.com
Cc: linux-ext4@...r.kernel.org,
"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
Subject: [PATCH -V3] ext4: code cleanup
rename some variables . We also unlock locks in the reverse
order we acquired as a part of cleanup.
FILENAME: In between
use-high-16-bits-of-bg-free-counts
fix-race-between-read_inode_bitmap-and-ext4_new_inode
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@...ux.vnet.ibm.com>
---
fs/ext4/balloc.c | 2 +-
fs/ext4/ialloc.c | 63 ++++++++++++++++++++++++++++------------------------
fs/ext4/mballoc.c | 2 +-
3 files changed, 36 insertions(+), 31 deletions(-)
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 8dd7b0d..3cae4c6 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -329,8 +329,8 @@ ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
ext4_init_block_bitmap(sb, bh, block_group, desc);
set_buffer_uptodate(bh);
- unlock_buffer(bh);
spin_unlock(sb_bgl_lock(EXT4_SB(sb), block_group));
+ unlock_buffer(bh);
return bh;
}
spin_unlock(sb_bgl_lock(EXT4_SB(sb), block_group));
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 84f060b..229708b 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -124,8 +124,8 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
if (desc->bg_flags & cpu_to_le16(EXT4_BG_INODE_UNINIT)) {
ext4_init_inode_bitmap(sb, bh, block_group, desc);
set_buffer_uptodate(bh);
- unlock_buffer(bh);
spin_unlock(sb_bgl_lock(EXT4_SB(sb), block_group));
+ unlock_buffer(bh);
return bh;
}
spin_unlock(sb_bgl_lock(EXT4_SB(sb), block_group));
@@ -585,8 +585,8 @@ static int find_group_other(struct super_block *sb, struct inode *parent,
struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode)
{
struct super_block *sb;
- struct buffer_head *bitmap_bh = NULL;
- struct buffer_head *bh2;
+ struct buffer_head *inode_bitmap_bh = NULL;
+ struct buffer_head *group_desc_bh;
ext4_group_t group = 0;
unsigned long ino = 0;
struct inode *inode;
@@ -634,40 +634,42 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode)
for (i = 0; i < sbi->s_groups_count; i++) {
err = -EIO;
- gdp = ext4_get_group_desc(sb, group, &bh2);
+ gdp = ext4_get_group_desc(sb, group, &group_desc_bh);
if (!gdp)
goto fail;
- brelse(bitmap_bh);
- bitmap_bh = ext4_read_inode_bitmap(sb, group);
- if (!bitmap_bh)
+ brelse(inode_bitmap_bh);
+ inode_bitmap_bh = ext4_read_inode_bitmap(sb, group);
+ if (!inode_bitmap_bh)
goto fail;
ino = 0;
repeat_in_this_group:
ino = ext4_find_next_zero_bit((unsigned long *)
- bitmap_bh->b_data, EXT4_INODES_PER_GROUP(sb), ino);
+ inode_bitmap_bh->b_data,
+ EXT4_INODES_PER_GROUP(sb), ino);
if (ino < EXT4_INODES_PER_GROUP(sb)) {
- BUFFER_TRACE(bitmap_bh, "get_write_access");
- err = ext4_journal_get_write_access(handle, bitmap_bh);
+ BUFFER_TRACE(inode_bitmap_bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle,
+ inode_bitmap_bh);
if (err)
goto fail;
if (!ext4_set_bit_atomic(sb_bgl_lock(sbi, group),
- ino, bitmap_bh->b_data)) {
+ ino, inode_bitmap_bh->b_data)) {
/* we won it */
- BUFFER_TRACE(bitmap_bh,
+ BUFFER_TRACE(inode_bitmap_bh,
"call ext4_journal_dirty_metadata");
err = ext4_journal_dirty_metadata(handle,
- bitmap_bh);
+ inode_bitmap_bh);
if (err)
goto fail;
goto got;
}
/* we lost it */
- jbd2_journal_release_buffer(handle, bitmap_bh);
+ jbd2_journal_release_buffer(handle, inode_bitmap_bh);
if (++ino < EXT4_INODES_PER_GROUP(sb))
goto repeat_in_this_group;
@@ -698,19 +700,21 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode)
goto fail;
}
- BUFFER_TRACE(bh2, "get_write_access");
- err = ext4_journal_get_write_access(handle, bh2);
- if (err) goto fail;
+ BUFFER_TRACE(group_desc_bh, "get_write_access");
+ err = ext4_journal_get_write_access(handle, group_desc_bh);
+ if (err)
+ goto fail;
/* We may have to initialize the block bitmap if it isn't already */
if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_GDT_CSUM) &&
gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
- struct buffer_head *block_bh = ext4_read_block_bitmap(sb, group);
+ struct buffer_head *block_bitmap_bh;
- BUFFER_TRACE(block_bh, "get block bitmap access");
- err = ext4_journal_get_write_access(handle, block_bh);
+ block_bitmap_bh = ext4_read_block_bitmap(sb, group);
+ BUFFER_TRACE(block_bitmap_bh, "get block bitmap access");
+ err = ext4_journal_get_write_access(handle, block_bitmap_bh);
if (err) {
- brelse(block_bh);
+ brelse(block_bitmap_bh);
goto fail;
}
@@ -718,8 +722,8 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode)
spin_lock(sb_bgl_lock(sbi, group));
/* recheck and clear flag under lock if we still need to */
if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
- gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
free = ext4_free_blocks_after_init(sb, group, gdp);
+ gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
ext4_free_blks_set(sb, gdp, free);
gdp->bg_checksum = ext4_group_desc_csum(sbi, group,
gdp);
@@ -728,11 +732,12 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode)
/* Don't need to dirty bitmap block if we didn't change it */
if (free) {
- BUFFER_TRACE(block_bh, "dirty block bitmap");
- err = ext4_journal_dirty_metadata(handle, block_bh);
+ BUFFER_TRACE(block_bitmap_bh, "dirty block bitmap");
+ err = ext4_journal_dirty_metadata(handle,
+ block_bitmap_bh);
}
- brelse(block_bh);
+ brelse(block_bitmap_bh);
if (err)
goto fail;
}
@@ -776,8 +781,8 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode)
}
gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
spin_unlock(sb_bgl_lock(sbi, group));
- BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
- err = ext4_journal_dirty_metadata(handle, bh2);
+ BUFFER_TRACE(group_desc_bh, "call ext4_journal_dirty_metadata");
+ err = ext4_journal_dirty_metadata(handle, group_desc_bh);
if (err) goto fail;
percpu_counter_dec(&sbi->s_freeinodes_counter);
@@ -876,7 +881,7 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode)
iput(inode);
ret = ERR_PTR(err);
really_out:
- brelse(bitmap_bh);
+ brelse(inode_bitmap_bh);
return ret;
fail_free_drop:
@@ -887,7 +892,7 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode *dir, int mode)
inode->i_flags |= S_NOQUOTA;
inode->i_nlink = 0;
iput(inode);
- brelse(bitmap_bh);
+ brelse(inode_bitmap_bh);
return ERR_PTR(err);
}
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index eb6aca6..97a2d4b 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -804,8 +804,8 @@ static int ext4_mb_init_cache(struct page *page, char *incore)
ext4_init_block_bitmap(sb, bh[i],
first_group + i, desc);
set_buffer_uptodate(bh[i]);
- unlock_buffer(bh[i]);
spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
+ unlock_buffer(bh[i]);
continue;
}
spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
--
1.6.0.4.735.gea4f
--
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