Messages in this thread Patch in this message | | | Date | Fri, 11 Jan 2002 15:52:28 -0500 | From | Chris Mason <> | Subject | Re: [reiserfs-dev] Re: [PATCH] expanding truncate |
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On Friday, January 04, 2002 12:33:32 PM -0500 Chris Mason <mason@suse.com> wrote:
[ expanding truncate patch ]
>> Seriously, it looks like a half-arsed and very old attempt to do common >> expanding truncate() for no-holes filesystems. BTW, these days rlimit >> checks are done by vmtruncate().
Ok, the rlimit checks where still there because generic_cont_expand is called before vmtruncate. I changed it around to match vmtruncate better though.
Does anyone still object to the patch below?
-chris
--- 0.22/fs/reiserfs/file.c Fri, 11 Jan 2002 14:17:09 -0500 +++ 0.22(w)/fs/reiserfs/file.c Fri, 11 Jan 2002 15:28:35 -0500 @@ -103,6 +103,20 @@ if (get_inode_item_key_version(inode) == KEY_FORMAT_3_5 && attr->ia_size > MAX_NON_LFS) return -EFBIG ; + + /* fill in hole pointers in the expanding truncate case. */ + if (attr->ia_size > inode->i_size) { + error = generic_cont_expand(inode, attr->ia_size) ; + if (inode->u.reiserfs_i.i_prealloc_count > 0) { + struct reiserfs_transaction_handle th ; + /* we're changing at most 2 bitmaps, inode + super */ + journal_begin(&th, inode->i_sb, 4) ; + reiserfs_discard_prealloc (&th, inode); + journal_end(&th, inode->i_sb, 4) ; + } + if (error) + return error ; + } } if ((((attr->ia_valid & ATTR_UID) && (attr->ia_uid & ~0xffff)) || --- 0.22/fs/reiserfs/inode.c Fri, 11 Jan 2002 14:17:09 -0500 +++ 0.22(w)/fs/reiserfs/inode.c Fri, 11 Jan 2002 14:43:42 -0500 @@ -2125,7 +2125,7 @@ /* we test for O_SYNC here so we can commit the transaction ** for any packed tails the file might have had */ - if (f->f_flags & O_SYNC) { + if (f && f->f_flags & O_SYNC) { lock_kernel() ; reiserfs_commit_for_inode(inode) ; unlock_kernel(); --- 0.22/fs/buffer.c Fri, 11 Jan 2002 11:53:37 -0500 +++ 0.22(w)/fs/buffer.c Fri, 11 Jan 2002 15:28:08 -0500 @@ -1760,6 +1760,52 @@ return 0; } +/* utility function for filesystems that need to do work on expanding + * truncates. Uses prepare/commit_write to allow the filesystem to + * deal with the hole. + */ +int generic_cont_expand(struct inode *inode, loff_t size) +{ + struct address_space *mapping = inode->i_mapping; + struct page *page; + unsigned long index, offset, limit; + int err; + + err = -EFBIG; + limit = current->rlim[RLIMIT_FSIZE].rlim_cur; + if (limit != RLIM_INFINITY && size > (loff_t)limit) { + send_sig(SIGXFSZ, current, 0); + goto out; + } + if (size > inode->i_sb->s_maxbytes) + goto out; + + offset = (size & (PAGE_CACHE_SIZE-1)); /* Within page */ + + /* ugh. in prepare/commit_write, if from==to==start of block, we + ** skip the prepare. make sure we never send an offset for the start + ** of a block + */ + if ((offset & (inode->i_sb->s_blocksize - 1)) == 0) { + offset++; + } + index = size >> PAGE_CACHE_SHIFT; + err = -ENOMEM; + page = grab_cache_page(mapping, index); + if (!page) + goto out; + err = mapping->a_ops->prepare_write(NULL, page, offset, offset); + if (!err) { + err = mapping->a_ops->commit_write(NULL, page, offset, offset); + } + UnlockPage(page); + page_cache_release(page); + if (err > 0) + err = 0; +out: + return err; +} + /* * For moronic filesystems that do not allow holes in file. * We may have to extend the file. --- 0.22/kernel/ksyms.c Fri, 11 Jan 2002 11:54:05 -0500 +++ 0.22(w)/kernel/ksyms.c Fri, 11 Jan 2002 14:17:35 -0500 @@ -204,6 +204,7 @@ EXPORT_SYMBOL(block_read_full_page); EXPORT_SYMBOL(block_prepare_write); EXPORT_SYMBOL(block_sync_page); +EXPORT_SYMBOL(generic_cont_expand); EXPORT_SYMBOL(cont_prepare_write); EXPORT_SYMBOL(generic_commit_write); EXPORT_SYMBOL(block_truncate_page); --- 0.22/include/linux/fs.h Fri, 11 Jan 2002 14:17:09 -0500 +++ 0.22(w)/include/linux/fs.h Fri, 11 Jan 2002 14:17:35 -0500 @@ -1416,6 +1416,7 @@ extern int block_prepare_write(struct page*, unsigned, unsigned, get_block_t*); extern int cont_prepare_write(struct page*, unsigned, unsigned, get_block_t*, unsigned long *); +extern int generic_cont_expand(struct inode *inode, loff_t size) ; extern int block_commit_write(struct page *page, unsigned from, unsigned to); extern int block_sync_page(struct page *);
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