From 73ce6abae5f95db071fa6626c88af64bd0d27c0f Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 28 Apr 2019 08:34:02 -0700 Subject: iomap: convert to SPDX identifier Use SPDX-License-Identifier instead of GPLv2 boilerplate. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/iomap.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) diff --git a/fs/iomap.c b/fs/iomap.c index abdd18e404f8..bfb1c74b16d3 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -1,15 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2010 Red Hat, Inc. * Copyright (c) 2016-2018 Christoph Hellwig. - * - * This program is free software; you can redistribute it and/or modify it - * under the terms and conditions of the GNU General Public License, - * version 2, as published by the Free Software Foundation. - * - * This program is distributed in the hope it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. */ #include #include -- cgit v1.2.3-59-g8ed1b From dbc582b6fb6ad6461085adfaae0106ae78721107 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 30 Apr 2019 08:45:33 -0700 Subject: iomap: Clean up __generic_write_end calling Move the call to __generic_write_end into iomap_write_end instead of duplicating it in each of the three branches. This requires open coding the generic_write_end for the buffer_head case. Signed-off-by: Christoph Hellwig Signed-off-by: Andreas Gruenbacher Reviewed-by: Jan Kara Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/iomap.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/fs/iomap.c b/fs/iomap.c index bfb1c74b16d3..9f159c39fbdc 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -730,13 +730,11 @@ __iomap_write_end(struct inode *inode, loff_t pos, unsigned len, * uptodate page as a zero-length write, and force the caller to redo * the whole thing. */ - if (unlikely(copied < len && !PageUptodate(page))) { - copied = 0; - } else { - iomap_set_range_uptodate(page, offset_in_page(pos), len); - iomap_set_page_dirty(page); - } - return __generic_write_end(inode, pos, copied, page); + if (unlikely(copied < len && !PageUptodate(page))) + return 0; + iomap_set_range_uptodate(page, offset_in_page(pos), len); + iomap_set_page_dirty(page); + return copied; } static int @@ -753,7 +751,6 @@ iomap_write_end_inline(struct inode *inode, struct page *page, kunmap_atomic(addr); mark_inode_dirty(inode); - __generic_write_end(inode, pos, copied, page); return copied; } @@ -766,12 +763,13 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len, if (iomap->type == IOMAP_INLINE) { ret = iomap_write_end_inline(inode, page, iomap, pos, copied); } else if (iomap->flags & IOMAP_F_BUFFER_HEAD) { - ret = generic_write_end(NULL, inode->i_mapping, pos, len, - copied, page, NULL); + ret = block_write_end(NULL, inode->i_mapping, pos, len, copied, + page, NULL); } else { ret = __iomap_write_end(inode, pos, len, copied, page, iomap); } + ret = __generic_write_end(inode, pos, ret, page); if (iomap->page_done) iomap->page_done(inode, pos, copied, page, iomap); -- cgit v1.2.3-59-g8ed1b From 26ddb1f4fd884258eeb8a8d7f2d40b163f00fedd Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Tue, 30 Apr 2019 08:45:33 -0700 Subject: fs: Turn __generic_write_end into a void function The VFS-internal __generic_write_end helper always returns the value of its @copied argument. This can be confusing, and it isn't very useful anyway, so turn __generic_write_end into a function returning void instead. Signed-off-by: Andreas Gruenbacher Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/buffer.c | 6 +++--- fs/internal.h | 2 +- fs/iomap.c | 2 +- 3 files changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index ce357602f471..e0d4c6a5e2d2 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2085,7 +2085,7 @@ int block_write_begin(struct address_space *mapping, loff_t pos, unsigned len, } EXPORT_SYMBOL(block_write_begin); -int __generic_write_end(struct inode *inode, loff_t pos, unsigned copied, +void __generic_write_end(struct inode *inode, loff_t pos, unsigned copied, struct page *page) { loff_t old_size = inode->i_size; @@ -2116,7 +2116,6 @@ int __generic_write_end(struct inode *inode, loff_t pos, unsigned copied, */ if (i_size_changed) mark_inode_dirty(inode); - return copied; } int block_write_end(struct file *file, struct address_space *mapping, @@ -2160,7 +2159,8 @@ int generic_write_end(struct file *file, struct address_space *mapping, struct page *page, void *fsdata) { copied = block_write_end(file, mapping, pos, len, copied, page, fsdata); - return __generic_write_end(mapping->host, pos, copied, page); + __generic_write_end(mapping->host, pos, copied, page); + return copied; } EXPORT_SYMBOL(generic_write_end); diff --git a/fs/internal.h b/fs/internal.h index 6a8b71643af4..530587fdf5d8 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -44,7 +44,7 @@ static inline int __sync_blockdev(struct block_device *bdev, int wait) extern void guard_bio_eod(int rw, struct bio *bio); extern int __block_write_begin_int(struct page *page, loff_t pos, unsigned len, get_block_t *get_block, struct iomap *iomap); -int __generic_write_end(struct inode *inode, loff_t pos, unsigned copied, +void __generic_write_end(struct inode *inode, loff_t pos, unsigned copied, struct page *page); /* diff --git a/fs/iomap.c b/fs/iomap.c index 9f159c39fbdc..4380d2c412f4 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -769,7 +769,7 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len, ret = __iomap_write_end(inode, pos, len, copied, page, iomap); } - ret = __generic_write_end(inode, pos, ret, page); + __generic_write_end(inode, pos, ret, page); if (iomap->page_done) iomap->page_done(inode, pos, copied, page, iomap); -- cgit v1.2.3-59-g8ed1b From 7a77dad7e3be1280456508841ccdd2a091b1906a Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Tue, 30 Apr 2019 08:45:34 -0700 Subject: iomap: Fix use-after-free error in page_done callback In iomap_write_end, we're not holding a page reference anymore when calling the page_done callback, but the callback needs that reference to access the page. To fix that, move the put_page call in __generic_write_end into the callers of __generic_write_end. Then, in iomap_write_end, put the page after calling the page_done callback. Reported-by: Jan Kara Fixes: 63899c6f8851 ("iomap: add a page_done callback") Signed-off-by: Andreas Gruenbacher Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/buffer.c | 2 +- fs/iomap.c | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/buffer.c b/fs/buffer.c index e0d4c6a5e2d2..0faa41fb4c88 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2104,7 +2104,6 @@ void __generic_write_end(struct inode *inode, loff_t pos, unsigned copied, } unlock_page(page); - put_page(page); if (old_size < pos) pagecache_isize_extended(inode, old_size, pos); @@ -2160,6 +2159,7 @@ int generic_write_end(struct file *file, struct address_space *mapping, { copied = block_write_end(file, mapping, pos, len, copied, page, fsdata); __generic_write_end(mapping->host, pos, copied, page); + put_page(page); return copied; } EXPORT_SYMBOL(generic_write_end); diff --git a/fs/iomap.c b/fs/iomap.c index 4380d2c412f4..e6453c1c831e 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -772,6 +772,7 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len, __generic_write_end(inode, pos, ret, page); if (iomap->page_done) iomap->page_done(inode, pos, copied, page, iomap); + put_page(page); if (ret < len) iomap_write_failed(inode, pos, len); -- cgit v1.2.3-59-g8ed1b From df0db3ecdb8fc942e9d812558b8e15ecd3e050b1 Mon Sep 17 00:00:00 2001 From: Andreas Gruenbacher Date: Tue, 30 Apr 2019 08:45:34 -0700 Subject: iomap: Add a page_prepare callback Move the page_done callback into a separate iomap_page_ops structure and add a page_prepare calback to be called before the next page is written to. In gfs2, we'll want to start a transaction in page_prepare and end it in page_done. Other filesystems that implement data journaling will require the same kind of mechanism. Signed-off-by: Andreas Gruenbacher Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/gfs2/bmap.c | 15 ++++++++++----- fs/iomap.c | 36 ++++++++++++++++++++++++++---------- include/linux/iomap.h | 22 +++++++++++++++++----- 3 files changed, 53 insertions(+), 20 deletions(-) diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 02b2646d84b3..f6d1a3893f5a 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -965,15 +965,20 @@ static void gfs2_write_unlock(struct inode *inode) gfs2_glock_dq_uninit(&ip->i_gh); } -static void gfs2_iomap_journaled_page_done(struct inode *inode, loff_t pos, - unsigned copied, struct page *page, - struct iomap *iomap) +static void gfs2_iomap_page_done(struct inode *inode, loff_t pos, + unsigned copied, struct page *page, + struct iomap *iomap) { struct gfs2_inode *ip = GFS2_I(inode); - gfs2_page_add_databufs(ip, page, offset_in_page(pos), copied); + if (page) + gfs2_page_add_databufs(ip, page, offset_in_page(pos), copied); } +static const struct iomap_page_ops gfs2_iomap_page_ops = { + .page_done = gfs2_iomap_page_done, +}; + static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos, loff_t length, unsigned flags, struct iomap *iomap, @@ -1051,7 +1056,7 @@ static int gfs2_iomap_begin_write(struct inode *inode, loff_t pos, } } if (!gfs2_is_stuffed(ip) && gfs2_is_jdata(ip)) - iomap->page_done = gfs2_iomap_journaled_page_done; + iomap->page_ops = &gfs2_iomap_page_ops; return 0; out_trans_end: diff --git a/fs/iomap.c b/fs/iomap.c index e6453c1c831e..fbfe20b7f6f0 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -657,6 +657,7 @@ static int iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, struct page **pagep, struct iomap *iomap) { + const struct iomap_page_ops *page_ops = iomap->page_ops; pgoff_t index = pos >> PAGE_SHIFT; struct page *page; int status = 0; @@ -666,9 +667,17 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, if (fatal_signal_pending(current)) return -EINTR; + if (page_ops && page_ops->page_prepare) { + status = page_ops->page_prepare(inode, pos, len, iomap); + if (status) + return status; + } + page = grab_cache_page_write_begin(inode->i_mapping, index, flags); - if (!page) - return -ENOMEM; + if (!page) { + status = -ENOMEM; + goto out_no_page; + } if (iomap->type == IOMAP_INLINE) iomap_read_inline_data(inode, page, iomap); @@ -676,15 +685,21 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, status = __block_write_begin_int(page, pos, len, NULL, iomap); else status = __iomap_write_begin(inode, pos, len, page, iomap); - if (unlikely(status)) { - unlock_page(page); - put_page(page); - page = NULL; - iomap_write_failed(inode, pos, len); - } + if (unlikely(status)) + goto out_unlock; *pagep = page; + return 0; + +out_unlock: + unlock_page(page); + put_page(page); + iomap_write_failed(inode, pos, len); + +out_no_page: + if (page_ops && page_ops->page_done) + page_ops->page_done(inode, pos, 0, NULL, iomap); return status; } @@ -758,6 +773,7 @@ static int iomap_write_end(struct inode *inode, loff_t pos, unsigned len, unsigned copied, struct page *page, struct iomap *iomap) { + const struct iomap_page_ops *page_ops = iomap->page_ops; int ret; if (iomap->type == IOMAP_INLINE) { @@ -770,8 +786,8 @@ iomap_write_end(struct inode *inode, loff_t pos, unsigned len, } __generic_write_end(inode, pos, ret, page); - if (iomap->page_done) - iomap->page_done(inode, pos, copied, page, iomap); + if (page_ops && page_ops->page_done) + page_ops->page_done(inode, pos, copied, page, iomap); put_page(page); if (ret < len) diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 0fefb5455bda..2103b94cb1bf 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -53,6 +53,8 @@ struct vm_fault; */ #define IOMAP_NULL_ADDR -1ULL /* addr is not valid */ +struct iomap_page_ops; + struct iomap { u64 addr; /* disk offset of mapping, bytes */ loff_t offset; /* file offset of mapping, bytes */ @@ -63,12 +65,22 @@ struct iomap { struct dax_device *dax_dev; /* dax_dev for dax operations */ void *inline_data; void *private; /* filesystem private */ + const struct iomap_page_ops *page_ops; +}; - /* - * Called when finished processing a page in the mapping returned in - * this iomap. At least for now this is only supported in the buffered - * write path. - */ +/* + * When a filesystem sets page_ops in an iomap mapping it returns, page_prepare + * and page_done will be called for each page written to. This only applies to + * buffered writes as unbuffered writes will not typically have pages + * associated with them. + * + * When page_prepare succeeds, page_done will always be called to do any + * cleanup work necessary. In that page_done call, @page will be NULL if the + * associated page could not be obtained. + */ +struct iomap_page_ops { + int (*page_prepare)(struct inode *inode, loff_t pos, unsigned len, + struct iomap *iomap); void (*page_done)(struct inode *inode, loff_t pos, unsigned copied, struct page *page, struct iomap *iomap); }; -- cgit v1.2.3-59-g8ed1b From cbbf4c0be8a725f08153949f45a85b2adafbbbd3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 1 May 2019 20:16:40 -0700 Subject: iomap: move iomap_read_inline_data around iomap_read_inline_data ended up being placed in the middle of the bio based read I/O completion handling, which tends to confuse the heck out of me whenever I follow the code. Move it to a more suitable place. Signed-off-by: Christoph Hellwig Reviewed-by: Dave Chinner Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/iomap.c | 40 ++++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-) diff --git a/fs/iomap.c b/fs/iomap.c index fbfe20b7f6f0..9ef049d61e8a 100644 --- a/fs/iomap.c +++ b/fs/iomap.c @@ -240,26 +240,6 @@ iomap_read_page_end_io(struct bio_vec *bvec, int error) iomap_read_finish(iop, page); } -static void -iomap_read_inline_data(struct inode *inode, struct page *page, - struct iomap *iomap) -{ - size_t size = i_size_read(inode); - void *addr; - - if (PageUptodate(page)) - return; - - BUG_ON(page->index); - BUG_ON(size > PAGE_SIZE - offset_in_page(iomap->inline_data)); - - addr = kmap_atomic(page); - memcpy(addr, iomap->inline_data, size); - memset(addr + size, 0, PAGE_SIZE - size); - kunmap_atomic(addr); - SetPageUptodate(page); -} - static void iomap_read_end_io(struct bio *bio) { @@ -281,6 +261,26 @@ struct iomap_readpage_ctx { struct list_head *pages; }; +static void +iomap_read_inline_data(struct inode *inode, struct page *page, + struct iomap *iomap) +{ + size_t size = i_size_read(inode); + void *addr; + + if (PageUptodate(page)) + return; + + BUG_ON(page->index); + BUG_ON(size > PAGE_SIZE - offset_in_page(iomap->inline_data)); + + addr = kmap_atomic(page); + memcpy(addr, iomap->inline_data, size); + memset(addr + size, 0, PAGE_SIZE - size); + kunmap_atomic(addr); + SetPageUptodate(page); +} + static loff_t iomap_readpage_actor(struct inode *inode, loff_t pos, loff_t length, void *data, struct iomap *iomap) -- cgit v1.2.3-59-g8ed1b