From bfab36e81611e60573b84eb4e4b4c8d8545b2320 Mon Sep 17 00:00:00 2001 From: Anton Altaparmakov Date: Fri, 12 Oct 2007 09:37:15 +0100 Subject: NTFS: Fix a mount time deadlock. Big thanks go to Mathias Kolehmainen for reporting the bug, providing debug output and testing the patches I sent him to get it working. The fix was to stop calling ntfs_attr_set() at mount time as that causes balance_dirty_pages_ratelimited() to be called which on systems with little memory actually tries to go and balance the dirty pages which tries to take the s_umount semaphore but because we are still in fill_super() across which the VFS holds s_umount for writing this results in a deadlock. We now do the dirty work by hand by submitting individual buffers. This has the annoying "feature" that mounting can take a few seconds if the journal is large as we have clear it all. One day someone should improve on this by deferring the journal clearing to a helper kernel thread so it can be done in the background but I don't have time for this at the moment and the current solution works fine so I am leaving it like this for now. Signed-off-by: Anton Altaparmakov Signed-off-by: Linus Torvalds --- fs/ntfs/file.c | 36 +++++++++++++++++------------------- 1 file changed, 17 insertions(+), 19 deletions(-) (limited to 'fs/ntfs/file.c') diff --git a/fs/ntfs/file.c b/fs/ntfs/file.c index ffcc504a1667..c814204d4ea0 100644 --- a/fs/ntfs/file.c +++ b/fs/ntfs/file.c @@ -1,7 +1,7 @@ /* * file.c - NTFS kernel file operations. Part of the Linux-NTFS project. * - * Copyright (c) 2001-2006 Anton Altaparmakov + * Copyright (c) 2001-2007 Anton Altaparmakov * * This program/include file is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as published @@ -26,7 +26,6 @@ #include #include #include -#include #include #include @@ -362,7 +361,7 @@ static inline void ntfs_fault_in_pages_readable(const char __user *uaddr, volatile char c; /* Set @end to the first byte outside the last page we care about. */ - end = (const char __user*)PAGE_ALIGN((ptrdiff_t __user)uaddr + bytes); + end = (const char __user*)PAGE_ALIGN((unsigned long)uaddr + bytes); while (!__get_user(c, uaddr) && (uaddr += PAGE_SIZE, uaddr < end)) ; @@ -532,7 +531,8 @@ static int ntfs_prepare_pages_for_non_resident_write(struct page **pages, blocksize_bits = vol->sb->s_blocksize_bits; u = 0; do { - struct page *page = pages[u]; + page = pages[u]; + BUG_ON(!page); /* * create_empty_buffers() will create uptodate/dirty buffers if * the page is uptodate/dirty. @@ -1291,7 +1291,7 @@ static inline size_t ntfs_copy_from_user(struct page **pages, size_t bytes) { struct page **last_page = pages + nr_pages; - char *kaddr; + char *addr; size_t total = 0; unsigned len; int left; @@ -1300,13 +1300,13 @@ static inline size_t ntfs_copy_from_user(struct page **pages, len = PAGE_CACHE_SIZE - ofs; if (len > bytes) len = bytes; - kaddr = kmap_atomic(*pages, KM_USER0); - left = __copy_from_user_inatomic(kaddr + ofs, buf, len); - kunmap_atomic(kaddr, KM_USER0); + addr = kmap_atomic(*pages, KM_USER0); + left = __copy_from_user_inatomic(addr + ofs, buf, len); + kunmap_atomic(addr, KM_USER0); if (unlikely(left)) { /* Do it the slow way. */ - kaddr = kmap(*pages); - left = __copy_from_user(kaddr + ofs, buf, len); + addr = kmap(*pages); + left = __copy_from_user(addr + ofs, buf, len); kunmap(*pages); if (unlikely(left)) goto err_out; @@ -1408,26 +1408,26 @@ static inline size_t ntfs_copy_from_user_iovec(struct page **pages, size_t *iov_ofs, size_t bytes) { struct page **last_page = pages + nr_pages; - char *kaddr; + char *addr; size_t copied, len, total = 0; do { len = PAGE_CACHE_SIZE - ofs; if (len > bytes) len = bytes; - kaddr = kmap_atomic(*pages, KM_USER0); - copied = __ntfs_copy_from_user_iovec_inatomic(kaddr + ofs, + addr = kmap_atomic(*pages, KM_USER0); + copied = __ntfs_copy_from_user_iovec_inatomic(addr + ofs, *iov, *iov_ofs, len); - kunmap_atomic(kaddr, KM_USER0); + kunmap_atomic(addr, KM_USER0); if (unlikely(copied != len)) { /* Do it the slow way. */ - kaddr = kmap(*pages); - copied = __ntfs_copy_from_user_iovec_inatomic(kaddr + ofs, + addr = kmap(*pages); + copied = __ntfs_copy_from_user_iovec_inatomic(addr + ofs, *iov, *iov_ofs, len); /* * Zero the rest of the target like __copy_from_user(). */ - memset(kaddr + ofs + copied, 0, len - copied); + memset(addr + ofs + copied, 0, len - copied); kunmap(*pages); if (unlikely(copied != len)) goto err_out; @@ -1735,8 +1735,6 @@ static int ntfs_commit_pages_after_write(struct page **pages, read_unlock_irqrestore(&ni->size_lock, flags); BUG_ON(initialized_size != i_size); if (end > initialized_size) { - unsigned long flags; - write_lock_irqsave(&ni->size_lock, flags); ni->initialized_size = end; i_size_write(vi, end); -- cgit v1.2.1