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bcachefs: Don't write past eof

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When converting from PAGE_SIZE to block_size, the .mkwrite path was
missed

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2019-09-19 18:05:04 -04:00 committed by Kent Overstreet
parent 9c37b63207
commit 6cc3535dcb
1 changed files with 27 additions and 5 deletions
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32
fs/bcachefs/fs-io.c
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@ -801,6 +801,8 @@ vm_fault_t bch2_page_mkwrite(struct vm_fault *vmf)
struct address_space *mapping = file->f_mapping;
struct bch_fs *c = inode->v.i_sb->s_fs_info;
struct bch2_page_reservation res;
unsigned len;
loff_t isize;
int ret = VM_FAULT_LOCKED;
bch2_page_reservation_init(c, inode, &res);
@ -817,21 +819,27 @@ vm_fault_t bch2_page_mkwrite(struct vm_fault *vmf)
bch2_pagecache_add_get(&inode->ei_pagecache_lock);
lock_page(page);
if (page->mapping != mapping ||
page_offset(page) > i_size_read(&inode->v)) {
isize = i_size_read(&inode->v);
if (page->mapping != mapping || page_offset(page) >= isize) {
unlock_page(page);
ret = VM_FAULT_NOPAGE;
goto out;
}
if (bch2_page_reservation_get(c, inode, page, &res,
0, PAGE_SIZE, true)) {
/* page is wholly or partially inside EOF */
if (((page->index + 1) << PAGE_SHIFT) <= isize)
len = PAGE_SIZE;
else
len = offset_in_page(isize);
if (bch2_page_reservation_get(c, inode, page, &res, 0, len, true)) {
unlock_page(page);
ret = VM_FAULT_SIGBUS;
goto out;
}
bch2_set_page_dirty(c, inode, page, &res, 0, PAGE_SIZE);
bch2_set_page_dirty(c, inode, page, &res, 0, len);
wait_for_stable_page(page);
out:
bch2_pagecache_add_put(&inode->ei_pagecache_lock);
@ -1433,6 +1441,10 @@ do_io:
BUG_ON(!bio_add_page(&w->io->op.op.wbio.bio, page,
sectors << 9, offset << 9));
/* Check for writing past i_size: */
BUG_ON((bio_end_sector(&w->io->op.op.wbio.bio) << 9) >
round_up(i_size, block_bytes(c)));
w->io->op.op.res.sectors += reserved_sectors;
w->io->op.new_i_size = i_size;
@ -2518,6 +2530,16 @@ int bch2_truncate(struct bch_inode_info *inode, struct iattr *iattr)
if (unlikely(ret))
goto err;
/*
* When extending, we're going to write the new i_size to disk
* immediately so we need to flush anything above the current on disk
* i_size first:
*
* Also, when extending we need to flush the page that i_size currently
* straddles - if it's mapped to userspace, we need to ensure that
* userspace has to redirty it and call .mkwrite -> set_page_dirty
* again to allocate the part of the page that was extended.
*/
if (iattr->ia_size > inode->ei_inode.bi_size)
ret = filemap_write_and_wait_range(mapping,
inode->ei_inode.bi_size,