From 2687a3569e40b1302f96698bcd6329aeb0ce3dd2 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Thu, 6 Dec 2007 11:18:49 -0500 Subject: Add lock_page_killable This routine is like lock_page, but can be interrupted by a fatal signal Signed-off-by: Matthew Wilcox --- mm/filemap.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'mm') diff --git a/mm/filemap.c b/mm/filemap.c index 188cf5fd3e8d..ac8f690d2885 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -173,6 +173,12 @@ static int sync_page(void *word) return 0; } +static int sync_page_killable(void *word) +{ + sync_page(word); + return fatal_signal_pending(current) ? -EINTR : 0; +} + /** * __filemap_fdatawrite_range - start writeback on mapping dirty pages in range * @mapping: address space structure to write @@ -577,6 +583,14 @@ void fastcall __lock_page(struct page *page) } EXPORT_SYMBOL(__lock_page); +int fastcall __lock_page_killable(struct page *page) +{ + DEFINE_WAIT_BIT(wait, &page->flags, PG_locked); + + return __wait_on_bit_lock(page_waitqueue(page), &wait, + sync_page_killable, TASK_KILLABLE); +} + /* * Variant of lock_page that does not require the caller to hold a reference * on the page's mapping. -- cgit v1.2.3 From 0b94e97a25d9b06ef17fca8da23169200bead1e2 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Thu, 6 Dec 2007 11:19:57 -0500 Subject: Use lock_page_killable Replacing lock_page with lock_page_killable in do_generic_mapping_read() allows us to kill `cat' of a file on an NFS-mounted filesystem Signed-off-by: Matthew Wilcox --- mm/filemap.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'mm') diff --git a/mm/filemap.c b/mm/filemap.c index ac8f690d2885..455119cc7f40 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -982,7 +982,8 @@ page_ok: page_not_up_to_date: /* Get exclusive access to the page ... */ - lock_page(page); + if (lock_page_killable(page)) + goto readpage_eio; /* Did it get truncated before we got the lock? */ if (!page->mapping) { @@ -1010,7 +1011,8 @@ readpage: } if (!PageUptodate(page)) { - lock_page(page); + if (lock_page_killable(page)) + goto readpage_eio; if (!PageUptodate(page)) { if (page->mapping == NULL) { /* @@ -1021,15 +1023,16 @@ readpage: goto find_page; } unlock_page(page); - error = -EIO; shrink_readahead_size_eio(filp, ra); - goto readpage_error; + goto readpage_eio; } unlock_page(page); } goto page_ok; +readpage_eio: + error = -EIO; readpage_error: /* UHHUH! A synchronous read error occurred. Report it */ desc->error = error; -- cgit v1.2.3