Messages in this thread | | | From | OGAWA Hirofumi <> | Subject | Re: [PATCH] fat: Fix non-atomic NFS i_pos read | Date | Sat, 30 Jun 2012 03:06:56 +0900 |
| |
"Steven J. Magnani" <steve@digidescorp.com> writes:
> fat_encode_fh() can fetch an invalid i_pos value on systems > where 64-bit accesses are not atomic. Make it use the same > accessor as the rest of the FAT code. > > Signed-off-by: Steven J. Magnani <steve@digidescorp.com> > --- > diff -uprN linux-3.5-rc4/fs/fat/inode.c new/fs/fat/inode.c > --- linux-3.5-rc4/fs/fat/inode.c 2012-06-29 11:20:12.781348652 -0500 > +++ new/fs/fat/inode.c 2012-06-29 11:25:29.484713183 -0500 > @@ -738,22 +738,22 @@ static int > fat_encode_fh(struct inode *inode, __u32 *fh, int *lenp, struct inode *parent) > { > int len = *lenp; > - u32 ipos_h, ipos_m, ipos_l; > + struct super_block *sb = inode->i_sb; > + struct msdos_sb_info *sbi = MSDOS_SB(sb);
sb seems to be unused. So, we can just
struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
true? Otherwise, ack.
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Just curious, this happened on the real system? I recently heard about NFS issue.
Thanks.
> + loff_t i_pos; > > if (len < 5) { > *lenp = 5; > return 255; /* no room */ > } > > - ipos_h = MSDOS_I(inode)->i_pos >> 8; > - ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24; > - ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28; > + i_pos = fat_i_pos_read(sbi, inode); > *lenp = 5; > fh[0] = inode->i_ino; > fh[1] = inode->i_generation; > - fh[2] = ipos_h; > - fh[3] = ipos_m | MSDOS_I(inode)->i_logstart; > - fh[4] = ipos_l; > + fh[2] = i_pos >> 8; > + fh[3] = ((i_pos & 0xf0) << 24) | MSDOS_I(inode)->i_logstart; > + fh[4] = (i_pos & 0x0f) << 28; > if (parent) > fh[4] |= MSDOS_I(parent)->i_logstart; > return 3; >
-- OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
| |