Messages in this thread |  | | | Date | Mon, 23 Oct 2006 21:39:44 +0100 | | Subject | Re: 2.6.19-rc2-mm2 : empty files on vfat file system | | From | (Mel Gorman) |
On (21/10/06 19:38), Damien Wyart didst pronounce: > > > I have noticed something strange (and bad :) since using > > > 2.6.19-rc2-mm2 (the problem is NOT present on 2.6.19-rc2-mm1 ; do > > > not know for mainline, I have not been able to test yet, but I think > > > there have not been recent changes in this area) : writing a file to > > > a vfat fs (fat 32) writes it, but with size 0 and no content. > > * OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> [2006-10-21 22:24]: > > diff -puN fs/fat/inode.c~fs-prepare_write-fixes fs/fat/inode.c > > --- a/fs/fat/inode.c~fs-prepare_write-fixes > > +++ a/fs/fat/inode.c > > @@ -150,7 +150,11 @@ static int fat_commit_write(struct file > > unsigned from, unsigned to) > > { > > struct inode *inode = page->mapping->host; > > - int err = generic_commit_write(file, page, from, to); > > + int err; > > + if (to - from > 0) > > + return 0; > > + > > + err = generic_commit_write(file, page, from, to); > > if (!err && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) { > > inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; > > MSDOS_I(inode)->i_attrs |= ATTR_ARCH; > > > This change does't update ->i_size. Could you just delete, and test > > it? Anyway, this seems wrong even if it's "if ((to - from) == 0)". > > Reverting the change makes the problem go away. But I do not know if > this is safe wrt the fs-prepare_write-fixes patch. >
I don't know about the fix, but the issue is pretty serious for IA64 and the EFI bootloader. On the IA64 I have access to, the bootloader and related files are stored on a VFAT file system so when an automated system ran a simple boot-test, the bootloader was blown away as a result.
-- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |