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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-07-10 08:53:21 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-07-10 08:53:21 -0700 |
commit | d02b0478c1acb00e9d9ee40810627eba5745d94b (patch) | |
tree | 9c522f00c574d8641c0242dd606ac30ea7909582 /fs | |
parent | f4c8824cbcc64524905f83388eb1139747829756 (diff) | |
parent | 20f829999c38b18e3d17f9e40dea3a28f721fac4 (diff) | |
download | linux-stable-d02b0478c1acb00e9d9ee40810627eba5745d94b.tar.gz linux-stable-d02b0478c1acb00e9d9ee40810627eba5745d94b.tar.bz2 linux-stable-d02b0478c1acb00e9d9ee40810627eba5745d94b.zip |
Merge tag 'gfs2-v5.8-rc4.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull gfs2 fixes from Andreas Gruenbacher:
"Fix gfs2 readahead deadlocks by adding a IOCB_NOIO flag that allows
gfs2 to use the generic fiel read iterator functions without having to
worry about being called back while holding locks".
* tag 'gfs2-v5.8-rc4.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Rework read and page fault locking
fs: Add IOCB_NOIO flag for generic_file_read_iter
Diffstat (limited to 'fs')
-rw-r--r-- | fs/gfs2/aops.c | 45 | ||||
-rw-r--r-- | fs/gfs2/file.c | 52 |
2 files changed, 51 insertions, 46 deletions
diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c index 72c9560f4467..68cd700a2719 100644 --- a/fs/gfs2/aops.c +++ b/fs/gfs2/aops.c @@ -468,21 +468,10 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page) } -/** - * __gfs2_readpage - readpage - * @file: The file to read a page for - * @page: The page to read - * - * This is the core of gfs2's readpage. It's used by the internal file - * reading code as in that case we already hold the glock. Also it's - * called by gfs2_readpage() once the required lock has been granted. - */ - static int __gfs2_readpage(void *file, struct page *page) { struct gfs2_inode *ip = GFS2_I(page->mapping->host); struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host); - int error; if (i_blocksize(page->mapping->host) == PAGE_SIZE && @@ -505,36 +494,11 @@ static int __gfs2_readpage(void *file, struct page *page) * gfs2_readpage - read a page of a file * @file: The file to read * @page: The page of the file - * - * This deals with the locking required. We have to unlock and - * relock the page in order to get the locking in the right - * order. */ static int gfs2_readpage(struct file *file, struct page *page) { - struct address_space *mapping = page->mapping; - struct gfs2_inode *ip = GFS2_I(mapping->host); - struct gfs2_holder gh; - int error; - - unlock_page(page); - gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); - error = gfs2_glock_nq(&gh); - if (unlikely(error)) - goto out; - error = AOP_TRUNCATED_PAGE; - lock_page(page); - if (page->mapping == mapping && !PageUptodate(page)) - error = __gfs2_readpage(file, page); - else - unlock_page(page); - gfs2_glock_dq(&gh); -out: - gfs2_holder_uninit(&gh); - if (error && error != AOP_TRUNCATED_PAGE) - lock_page(page); - return error; + return __gfs2_readpage(file, page); } /** @@ -598,16 +562,9 @@ static void gfs2_readahead(struct readahead_control *rac) { struct inode *inode = rac->mapping->host; struct gfs2_inode *ip = GFS2_I(inode); - struct gfs2_holder gh; - gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); - if (gfs2_glock_nq(&gh)) - goto out_uninit; if (!gfs2_is_stuffed(ip)) mpage_readahead(rac, gfs2_block_map); - gfs2_glock_dq(&gh); -out_uninit: - gfs2_holder_uninit(&gh); } /** diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index fe305e4bfd37..bebde537ac8c 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -558,8 +558,29 @@ out_uninit: return block_page_mkwrite_return(ret); } +static vm_fault_t gfs2_fault(struct vm_fault *vmf) +{ + struct inode *inode = file_inode(vmf->vma->vm_file); + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_holder gh; + vm_fault_t ret; + int err; + + gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); + err = gfs2_glock_nq(&gh); + if (err) { + ret = block_page_mkwrite_return(err); + goto out_uninit; + } + ret = filemap_fault(vmf); + gfs2_glock_dq(&gh); +out_uninit: + gfs2_holder_uninit(&gh); + return ret; +} + static const struct vm_operations_struct gfs2_vm_ops = { - .fault = filemap_fault, + .fault = gfs2_fault, .map_pages = filemap_map_pages, .page_mkwrite = gfs2_page_mkwrite, }; @@ -824,6 +845,9 @@ out_uninit: static ssize_t gfs2_file_read_iter(struct kiocb *iocb, struct iov_iter *to) { + struct gfs2_inode *ip; + struct gfs2_holder gh; + size_t written = 0; ssize_t ret; if (iocb->ki_flags & IOCB_DIRECT) { @@ -832,7 +856,31 @@ static ssize_t gfs2_file_read_iter(struct kiocb *iocb, struct iov_iter *to) return ret; iocb->ki_flags &= ~IOCB_DIRECT; } - return generic_file_read_iter(iocb, to); + iocb->ki_flags |= IOCB_NOIO; + ret = generic_file_read_iter(iocb, to); + iocb->ki_flags &= ~IOCB_NOIO; + if (ret >= 0) { + if (!iov_iter_count(to)) + return ret; + written = ret; + } else { + if (ret != -EAGAIN) + return ret; + if (iocb->ki_flags & IOCB_NOWAIT) + return ret; + } + ip = GFS2_I(iocb->ki_filp->f_mapping->host); + gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); + ret = gfs2_glock_nq(&gh); + if (ret) + goto out_uninit; + ret = generic_file_read_iter(iocb, to); + if (ret > 0) + written += ret; + gfs2_glock_dq(&gh); +out_uninit: + gfs2_holder_uninit(&gh); + return written ? written : ret; } /** |