I also have commented a possible bug in existing ext2 code, marked with XXX.
Cc: linux-ext4@xxxxxxxxxxxxxxx
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
---
fs/ext2/ext2.h | 1
fs/ext2/file.c | 2
fs/ext2/inode.c | 142 +++++++++++++++++++++++++++++++++++++++++++++-----------
3 files changed, 116 insertions(+), 29 deletions(-)
Index: linux-2.6/fs/ext2/inode.c
===================================================================
--- linux-2.6.orig/fs/ext2/inode.c
+++ linux-2.6/fs/ext2/inode.c
@@ -53,6 +53,8 @@ static inline int ext2_inode_is_fast_sym
inode->i_blocks - ea_blocks == 0);
}
+static void ext2_truncate_blocks(struct inode *inode, loff_t offset);
+
/*
* Called at the last iput() if i_nlink is zero.
*/
@@ -68,7 +70,7 @@ void ext2_delete_inode (struct inode * i
inode->i_size = 0;
if (inode->i_blocks)
- ext2_truncate (inode);
+ ext2_truncate_blocks(inode, 0);
ext2_free_inode (inode);
return;
@@ -761,8 +763,33 @@ ext2_write_begin(struct file *file, stru
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
+ int ret;
+
*pagep = NULL;
- return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata);
+ ret = __ext2_write_begin(file, mapping, pos, len, flags, pagep, fsdata);
+ if (ret < 0) {
+ struct inode *inode = mapping->host;
+ loff_t isize = inode->i_size;
+ if (pos + len > isize)
+ ext2_truncate_blocks(inode, isize);
+ }
+ return ret;
+}
+
+static int ext2_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ int ret;
+
+ ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
+ if (ret < len) {
+ struct inode *inode = mapping->host;
+ loff_t isize = inode->i_size;
+ if (pos + len > isize)
+ ext2_truncate_blocks(inode, isize);
+ }
+ return ret;
}
static int
@@ -770,13 +797,22 @@ ext2_nobh_write_begin(struct file *file,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
+ int ret;
+
/*
* Dir-in-pagecache still uses ext2_write_begin. Would have to rework
* directory handling code to pass around offsets rather than struct
* pages in order to make this work easily.
*/
- return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+ ret = nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
ext2_get_block);
+ if (ret < 0) {
+ struct inode *inode = mapping->host;
+ loff_t isize = inode->i_size;
+ if (pos + len > isize)
+ ext2_truncate_blocks(inode, isize);
+ }
+ return ret;
}
static int ext2_nobh_writepage(struct page *page,
@@ -796,9 +832,15 @@ ext2_direct_IO(int rw, struct kiocb *ioc
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
+ ssize_t ret;
- return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
+ ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
offset, nr_segs, ext2_get_block, NULL);
+ if (ret < 0 && (rw & WRITE)) {
+ loff_t isize = inode->i_size;
+ ext2_truncate_blocks(inode, isize);
+ }
+ return ret;
}
static int
@@ -813,7 +855,7 @@ const struct address_space_operations ex
.writepage = ext2_writepage,
.sync_page = block_sync_page,
.write_begin = ext2_write_begin,
- .write_end = generic_write_end,
+ .write_end = ext2_write_end,
.bmap = ext2_bmap,
.direct_IO = ext2_direct_IO,
.writepages = ext2_writepages,
@@ -1020,7 +1062,7 @@ static void ext2_free_branches(struct in
ext2_free_data(inode, p, q);
}
-void ext2_truncate(struct inode *inode)
+static void __ext2_truncate_blocks(struct inode *inode, loff_t offset)
{
__le32 *i_data = EXT2_I(inode)->i_data;
struct ext2_inode_info *ei = EXT2_I(inode);
@@ -1032,27 +1074,8 @@ void ext2_truncate(struct inode *inode)
int n;
long iblock;
unsigned blocksize;
-
- if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
- S_ISLNK(inode->i_mode)))
- return;
- if (ext2_inode_is_fast_symlink(inode))
- return;
- if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
- return;
-
blocksize = inode->i_sb->s_blocksize;
- iblock = (inode->i_size + blocksize-1)
- >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
-
- if (mapping_is_xip(inode->i_mapping))
- xip_truncate_page(inode->i_mapping, inode->i_size);
- else if (test_opt(inode->i_sb, NOBH))
- nobh_truncate_page(inode->i_mapping,
- inode->i_size, ext2_get_block);
- else
- block_truncate_page(inode->i_mapping,
- inode->i_size, ext2_get_block);
+ iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
n = ext2_block_to_path(inode, iblock, offsets, NULL);
if (n == 0)
@@ -1120,6 +1143,62 @@ do_indirects:
ext2_discard_reservation(inode);
mutex_unlock(&ei->truncate_mutex);
+}
+
+static void ext2_truncate_blocks(struct inode *inode, loff_t offset)
+{
+ /*
+ * XXX: it seems like a bug here that we don't allow
+ * IS_APPEND inode to have blocks-past-i_size trimmed off.
+ * review and fix this.
+ *
+ * Also would be nice to be able to handle IO errors and such,
+ * but that's probably too much to ask.
+ */
+ if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+ S_ISLNK(inode->i_mode)))
+ return;
+ if (ext2_inode_is_fast_symlink(inode))
+ return;
+ if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+ return;
+ __ext2_truncate_blocks(inode, offset);
+}
+
+int ext2_setsize(struct inode *inode, loff_t newsize)
+{
+ loff_t oldsize;
+ int error;
+
+ error = inode_newsize_ok(inode, newsize);
+ if (error)
+ return error;
+
+ if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
+ S_ISLNK(inode->i_mode)))
+ return -EINVAL;
+ if (ext2_inode_is_fast_symlink(inode))
+ return -EINVAL;
+ if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
+ return -EPERM;
+
+ if (mapping_is_xip(inode->i_mapping))
+ error = xip_truncate_page(inode->i_mapping, newsize);
+ else if (test_opt(inode->i_sb, NOBH))
+ error = nobh_truncate_page(inode->i_mapping,
+ newsize, ext2_get_block);
+ else
+ error = block_truncate_page(inode->i_mapping,
+ newsize, ext2_get_block);
+ if (error)
+ return error;
+
+ oldsize = inode->i_size;
+ i_size_write(inode, newsize);
+ truncate_pagecache(inode, oldsize, newsize);
+
+ __ext2_truncate_blocks(inode, newsize);
+
inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
if (inode_needs_sync(inode)) {
sync_mapping_buffers(inode->i_mapping);
@@ -1127,6 +1206,8 @@ do_indirects:
} else {
mark_inode_dirty(inode);
}
+
+ return 0;
}
static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino,
@@ -1459,8 +1540,15 @@ int ext2_setattr(struct dentry *dentry,
if (error)
return error;
}
- error = inode_setattr(inode, iattr);
+ if (iattr->ia_valid & ATTR_SIZE) {
+ error = ext2_setsize(inode, iattr->ia_size);
+ if (error)
+ return error;
+ }
+ generic_setattr(inode, iattr);
if (!error && (iattr->ia_valid & ATTR_MODE))
error = ext2_acl_chmod(inode);
+ mark_inode_dirty(inode);
+
return error;
}
Index: linux-2.6/fs/ext2/ext2.h
===================================================================
--- linux-2.6.orig/fs/ext2/ext2.h
+++ linux-2.6/fs/ext2/ext2.h
@@ -122,7 +122,6 @@ extern int ext2_write_inode (struct inod
extern void ext2_delete_inode (struct inode *);
extern int ext2_sync_inode (struct inode *);
extern int ext2_get_block(struct inode *, sector_t, struct buffer_head *, int);
-extern void ext2_truncate (struct inode *);
extern int ext2_setattr (struct dentry *, struct iattr *);
extern void ext2_set_inode_flags(struct inode *inode);
extern void ext2_get_inode_flags(struct ext2_inode_info *);
Index: linux-2.6/fs/ext2/file.c
===================================================================
--- linux-2.6.orig/fs/ext2/file.c
+++ linux-2.6/fs/ext2/file.c
@@ -77,13 +77,13 @@ const struct file_operations ext2_xip_fi
#endif
const struct inode_operations ext2_file_inode_operations = {
- .truncate = ext2_truncate,
#ifdef CONFIG_EXT2_FS_XATTR
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.listxattr = ext2_listxattr,
.removexattr = generic_removexattr,
#endif
+ .new_truncate = 1,
.setattr = ext2_setattr,
.permission = ext2_permission,
.fiemap = ext2_fiemap,
--
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