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Message-Id: <1289929249-4863-1-git-send-email-abogani@texware.it>
Date: Tue, 16 Nov 2010 18:40:47 +0100
From: Alessio Igor Bogani <abogani@...ware.it>
To: Jan Kara <jack@...e.cz>, Arnd Bergmann <arnd@...db.de>
Cc: Christoph Hellwig <hch@...radead.org>,
Tim Bird <tim.bird@...sony.com>,
LKML <linux-kernel@...r.kernel.org>,
linux-fsdevel@...r.kernel.org,
Alessio Igor Bogani <abogani@...ware.it>
Subject: [PATCH 1/3] udf: Replace bkl with the inode->i_alloc_sem for protect udf_inode_info struct
Replace bkl with the inode->i_alloc_sem rw semaphore in udf_release_file(),
udf_symlink(), udf_symlink_filler(), udf_get_block() and udf_block_map().
Add protection in udf_evict_inode() using the same i_alloc_sem rw semaphore.
This work was supported by a hardware donation from the CE Linux Forum.
Signed-off-by: Alessio Igor Bogani <abogani@...ware.it>
---
fs/udf/file.c | 4 ++--
fs/udf/inode.c | 11 +++++++----
fs/udf/namei.c | 4 ++--
fs/udf/symlink.c | 12 +++++++-----
fs/udf/udf_i.h | 9 +++++++++
5 files changed, 27 insertions(+), 13 deletions(-)
diff --git a/fs/udf/file.c b/fs/udf/file.c
index 66b9e7e..4cb0f7a 100644
--- a/fs/udf/file.c
+++ b/fs/udf/file.c
@@ -204,10 +204,10 @@ static int udf_release_file(struct inode *inode, struct file *filp)
{
if (filp->f_mode & FMODE_WRITE) {
mutex_lock(&inode->i_mutex);
- lock_kernel();
+ down_write(&inode->i_alloc_sem);
udf_discard_prealloc(inode);
udf_truncate_tail_extent(inode);
- unlock_kernel();
+ up_write(&inode->i_alloc_sem);
mutex_unlock(&inode->i_mutex);
}
return 0;
diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index fa3c154..14e3f56 100644
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -79,7 +79,9 @@ void udf_evict_inode(struct inode *inode)
if (!inode->i_nlink && !is_bad_inode(inode)) {
want_delete = 1;
inode->i_size = 0;
+ down_write(&inode->i_alloc_sem);
udf_truncate(inode);
+ up_write(&inode->i_alloc_sem);
udf_update_inode(inode, IS_SYNC(inode));
}
invalidate_inode_buffers(inode);
@@ -302,9 +304,10 @@ static int udf_get_block(struct inode *inode, sector_t block,
new = 0;
bh = NULL;
- lock_kernel();
+ down_write(&inode->i_alloc_sem);
iinfo = UDF_I(inode);
+
if (block == iinfo->i_next_alloc_block + 1) {
iinfo->i_next_alloc_block++;
iinfo->i_next_alloc_goal++;
@@ -323,7 +326,7 @@ static int udf_get_block(struct inode *inode, sector_t block,
map_bh(bh_result, inode->i_sb, phys);
abort:
- unlock_kernel();
+ up_write(&inode->i_alloc_sem);
return err;
}
@@ -2043,7 +2046,7 @@ long udf_block_map(struct inode *inode, sector_t block)
struct extent_position epos = {};
int ret;
- lock_kernel();
+ down_read(&inode->i_alloc_sem);
if (inode_bmap(inode, block, &epos, &eloc, &elen, &offset) ==
(EXT_RECORDED_ALLOCATED >> 30))
@@ -2051,7 +2054,7 @@ long udf_block_map(struct inode *inode, sector_t block)
else
ret = 0;
- unlock_kernel();
+ up_read(&inode->i_alloc_sem);
brelse(epos.bh);
if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_VARCONV))
diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index 701fcda..5aa2ca6 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -893,11 +893,11 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
struct udf_inode_info *iinfo;
struct super_block *sb = dir->i_sb;
- lock_kernel();
inode = udf_new_inode(dir, S_IFLNK | S_IRWXUGO, &err);
if (!inode)
goto out;
+ down_write(&inode->i_alloc_sem);
name = kmalloc(UDF_NAME_LEN, GFP_NOFS);
if (!name) {
err = -ENOMEM;
@@ -1032,10 +1032,10 @@ static int udf_symlink(struct inode *dir, struct dentry *dentry,
out:
kfree(name);
- unlock_kernel();
return err;
out_no_entry:
+ up_write(&inode->i_alloc_sem);
inode_dec_link_count(inode);
iput(inode);
goto out;
diff --git a/fs/udf/symlink.c b/fs/udf/symlink.c
index 1606478..358673d 100644
--- a/fs/udf/symlink.c
+++ b/fs/udf/symlink.c
@@ -27,7 +27,6 @@
#include <linux/mm.h>
#include <linux/stat.h>
#include <linux/pagemap.h>
-#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include "udf_i.h"
@@ -78,13 +77,16 @@ static int udf_symlink_filler(struct file *file, struct page *page)
int err = -EIO;
unsigned char *p = kmap(page);
struct udf_inode_info *iinfo;
+ uint32_t pos;
- lock_kernel();
iinfo = UDF_I(inode);
+ pos = udf_block_map(inode, 0);
+
+ down_read(&inode->i_alloc_sem);
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
symlink = iinfo->i_ext.i_data + iinfo->i_lenEAttr;
} else {
- bh = sb_bread(inode->i_sb, udf_block_map(inode, 0));
+ bh = sb_bread(inode->i_sb, pos);
if (!bh)
goto out;
@@ -95,14 +97,14 @@ static int udf_symlink_filler(struct file *file, struct page *page)
udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p);
brelse(bh);
- unlock_kernel();
+ up_read(&inode->i_alloc_sem);
SetPageUptodate(page);
kunmap(page);
unlock_page(page);
return 0;
out:
- unlock_kernel();
+ up_read(&inode->i_alloc_sem);
SetPageError(page);
kunmap(page);
unlock_page(page);
diff --git a/fs/udf/udf_i.h b/fs/udf/udf_i.h
index e58d1de..d5026ae 100644
--- a/fs/udf/udf_i.h
+++ b/fs/udf/udf_i.h
@@ -1,6 +1,15 @@
#ifndef _UDF_I_H
#define _UDF_I_H
+/*
+ * The i_alloc_sem serves for protection of allocation information of a regular
+ * files and symlinks. This includes all extents belonging to the file/symlink,
+ * preallocation, and goal block information. When extents are read,
+ * i_alloc_sem must be held for reading, when extents are changed, i_alloc_sem
+ * must be held for writing. For directories i_mutex is used for all the
+ * necessary protection.
+ */
+
struct udf_inode_info {
struct timespec i_crtime;
/* Physical address of inode */
--
1.7.0.4
--
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