From 905685f68fc72844b8c2689c39a5c6c35e840152 Mon Sep 17 00:00:00 2001 From: Anton Altaparmakov Date: Thu, 10 Mar 2005 11:06:19 +0000 Subject: NTFS: - Modify ->readpage and ->writepage (fs/ntfs/aops.c) so they detect and handle the case where an attribute is converted from resident to non-resident by a concurrent file write. - Reorder some operations when converting an attribute from resident to non-resident (fs/ntfs/attrib.c) so it is safe wrt concurrent ->readpage and ->writepage. Signed-off-by: Anton Altaparmakov --- fs/ntfs/aops.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'fs/ntfs/aops.c') diff --git a/fs/ntfs/aops.c b/fs/ntfs/aops.c index 2a7cba258cc..6241c4cfbe2 100644 --- a/fs/ntfs/aops.c +++ b/fs/ntfs/aops.c @@ -355,6 +355,7 @@ static int ntfs_readpage(struct file *file, struct page *page) u32 attr_len; int err = 0; +retry_readpage: BUG_ON(!PageLocked(page)); /* * This can potentially happen because we clear PageUptodate() during @@ -408,6 +409,14 @@ static int ntfs_readpage(struct file *file, struct page *page) err = PTR_ERR(mrec); goto err_out; } + /* + * If a parallel write made the attribute non-resident, drop the mft + * record and retry the readpage. + */ + if (unlikely(NInoNonResident(ni))) { + unmap_mft_record(base_ni); + goto retry_readpage; + } ctx = ntfs_attr_get_search_ctx(base_ni, mrec); if (unlikely(!ctx)) { err = -ENOMEM; @@ -1248,6 +1257,7 @@ static int ntfs_writepage(struct page *page, struct writeback_control *wbc) u32 attr_len; int err; +retry_writepage: BUG_ON(!PageLocked(page)); i_size = i_size_read(vi); /* Is the page fully outside i_size? (truncate in progress) */ @@ -1338,6 +1348,14 @@ static int ntfs_writepage(struct page *page, struct writeback_control *wbc) ctx = NULL; goto err_out; } + /* + * If a parallel write made the attribute non-resident, drop the mft + * record and retry the writepage. + */ + if (unlikely(NInoNonResident(ni))) { + unmap_mft_record(base_ni); + goto retry_writepage; + } ctx = ntfs_attr_get_search_ctx(base_ni, m); if (unlikely(!ctx)) { err = -ENOMEM; -- cgit v1.2.3