| Message ID | 20171127173709.20787-1-andi@firstfloor.org |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | ext4: Support fast symlinks from ext3 file systems | expand |
On Nov 27, 2017, at 10:37 AM, Andi Kleen <andi@firstfloor.org> wrote: > > From: Andi Kleen <ak@linux.intel.com> > > dbb3c27f5b91c4 (ext4: change fast symlink test to not rely on i_blocks) > broke ~10 years old ext3 file systems created by 2.6.17. Any ELF > executable fails because the /lib/ld-linux.so.2 fast symlink > cannot be read anymore. > > The patch assumed fast symlinks were created in a specific way, > but that's not true on these really old file systems. > > The new behavior is apparently needed only with the large EA inode > feature. > > Revert to the old behavior if the large EA inode feature is not set. > > This makes my old VM boot again. > > Fixes: dbb3c27f5b91c4 (ext4: change fast symlink test to not rely ...) > Signed-off-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Andreas Dilger <adilger@dilger.ca> > --- > fs/ext4/inode.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 0992d76f7ab1..6b82b0ff5e0b 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -149,6 +149,15 @@ static int ext4_meta_trans_blocks(struct inode *inode, int lblocks, > */ > int ext4_inode_is_fast_symlink(struct inode *inode) > { > + if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) { > + int ea_blocks = EXT4_I(inode)->i_file_acl ? > + EXT4_CLUSTER_SIZE(inode->i_sb) >> 9 : 0; > + > + if (ext4_has_inline_data(inode)) > + return 0; > + > + return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0); > + } > return S_ISLNK(inode->i_mode) && inode->i_size && > (inode->i_size < EXT4_N_BLOCKS * 4); > } > -- > 2.13.6 > Cheers, Andreas
On Mon, Nov 27, 2017 at 11:08:53AM -0700, Andreas Dilger wrote: > On Nov 27, 2017, at 10:37 AM, Andi Kleen <andi@firstfloor.org> wrote: > > > > From: Andi Kleen <ak@linux.intel.com> > > > > dbb3c27f5b91c4 (ext4: change fast symlink test to not rely on i_blocks) > > broke ~10 years old ext3 file systems created by 2.6.17. Any ELF > > executable fails because the /lib/ld-linux.so.2 fast symlink > > cannot be read anymore. > > > > The patch assumed fast symlinks were created in a specific way, > > but that's not true on these really old file systems. > > > > The new behavior is apparently needed only with the large EA inode > > feature. > > > > Revert to the old behavior if the large EA inode feature is not set. > > > > This makes my old VM boot again. > > > > Fixes: dbb3c27f5b91c4 (ext4: change fast symlink test to not rely ...) > > Signed-off-by: Andi Kleen <ak@linux.intel.com> > > Reviewed-by: Andreas Dilger <adilger@dilger.ca> Thanks, applied. - Ted
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 0992d76f7ab1..6b82b0ff5e0b 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -149,6 +149,15 @@ static int ext4_meta_trans_blocks(struct inode *inode, int lblocks, */ int ext4_inode_is_fast_symlink(struct inode *inode) { + if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) { + int ea_blocks = EXT4_I(inode)->i_file_acl ? + EXT4_CLUSTER_SIZE(inode->i_sb) >> 9 : 0; + + if (ext4_has_inline_data(inode)) + return 0; + + return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0); + } return S_ISLNK(inode->i_mode) && inode->i_size && (inode->i_size < EXT4_N_BLOCKS * 4); }