I also have commented a possible bug in existing ext2 code, marked with XXX. Cc: linux-ext4@vger.kernel.org Cc: Christoph Hellwig Signed-off-by: Nick Piggin --- 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, -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html