linux/fs, branch v3.4.2

ext4: don't set i_flags in EXT4_IOC_SETFLAGS

2012-06-09T15:36:19Z

commit b22b1f178f6799278d3178d894f37facb2085765 upstream. Commit 7990696 uses the ext4_{set,clear}_inode_flags() functions to change the i_flags automatically but fails to remove the error setting of i_flags. So we still have the problem of trashing state flags. Fix this by removing the assignment. Signed-off-by: Tao Ma Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

vfs: Fix /proc//fdinfo/ file handling

2012-06-09T15:36:18Z

commit 0640113be25d283e0ff77a9f041e1242182387f0 upstream. Cyrill Gorcunov reports that I broke the fdinfo files with commit 30a08bf2d31d ("proc: move fd symlink i_mode calculations into tid_fd_revalidate()"), and he's quite right. The tid_fd_revalidate() function is not just used for the /fd symlinks, it's also used for the /fdinfo/ files, and the permission model for those are different. So do the dynamic symlink permission handling just for symlinks, making the fdinfo files once more appear as the proper regular files they are. Of course, Al Viro argued (probably correctly) that we shouldn't do the symlink permission games at all, and make the symlinks always just be the normal 'lrwxrwxrwx'. That would have avoided this issue too, but since somebody noticed that the permissions had changed (which was the reason for that original commit 30a08bf2d31d in the first place), people do apparently use this feature. [ Basically, you can use the symlink permission data as a cheap "fdinfo" replacement, since you see whether the file is open for reading and/or writing by just looking at st_mode of the symlink. So the feature does make sense, even if the pain it has caused means we probably shouldn't have done it to begin with. ] Reported-and-tested-by: Cyrill Gorcunov Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

ext4: remove mb_groups before tearing down the buddy_cache

2012-06-09T15:36:16Z

commit 95599968d19db175829fb580baa6b68939b320fb upstream. We can't have references held on pages in the s_buddy_cache while we are trying to truncate its pages and put the inode. All the pages must be gone before we reach clear_inode. This can only be gauranteed if we can prevent new users from grabbing references to s_buddy_cache's pages. The original bug can be reproduced and the bug fix can be verified by: while true; do mount -t ext4 /dev/ram0 /export/hda3/ram0; \ umount /export/hda3/ram0; done & while true; do cat /proc/fs/ext4/ram0/mb_groups; done Signed-off-by: Salman Qazi Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: add ext4_mb_unload_buddy in the error path

2012-06-09T15:36:16Z

commit 02b7831019ea4e7994968c84b5826fa8b248ffc8 upstream. ext4_free_blocks fails to pair an ext4_mb_load_buddy with a matching ext4_mb_unload_buddy when it fails a memory allocation. Signed-off-by: Salman Qazi Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: don't trash state flags in EXT4_IOC_SETFLAGS

2012-06-09T15:36:16Z

commit 79906964a187c405db72a3abc60eb9b50d804fbc upstream. In commit 353eb83c we removed i_state_flags with 64-bit longs, But when handling the EXT4_IOC_SETFLAGS ioctl, we replace i_flags directly, which trashes the state flags which are stored in the high 32-bits of i_flags on 64-bit platforms. So use the the ext4_{set,clear}_inode_flags() functions which use atomic bit manipulation functions instead. Reported-by: Tao Ma Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: add missing save_error_info() to ext4_error()

2012-06-09T15:36:16Z

commit f3fc0210c0fc91900766c995f089c39170e68305 upstream. The ext4_error() function is missing a call to save_error_info(). Since this is the function which marks the file system as containing an error, this oversight (which was introduced in 2.6.36) is quite significant, and should be backported to older stable kernels with high urgency. Reported-by: Ken Sumrall Signed-off-by: "Theodore Ts'o" Cc: ksumrall@google.com Signed-off-by: Greg Kroah-Hartman

ext4: disallow hard-linked directory in ext4_lookup

2012-06-09T15:36:16Z

commit 7e936b737211e6b54e34b71a827e56b872e958d8 upstream. A hard-linked directory to its parent can cause the VFS to deadlock, and is a sign of a corrupted file system. So detect this case in ext4_lookup(), before the rmdir() lockup scenario can take place. Signed-off-by: Andreas Dilger Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: fix potential integer overflow in alloc_flex_gd()

2012-06-09T15:36:16Z

commit 967ac8af4475ce45474800709b12137aa7634c77 upstream. In alloc_flex_gd(), when flexbg_size is large, kmalloc size would overflow and flex_gd->groups would point to a buffer smaller than expected, causing OOB accesses when it is used. Note that in ext4_resize_fs(), flexbg_size is calculated using sbi->s_log_groups_per_flex, which is read from the disk and only bounded to [1, 31]. The patch returns NULL for too large flexbg_size. Reviewed-by: Eric Sandeen Signed-off-by: Haogang Chen Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: force ro mount if ext4_setup_super() fails

2012-06-09T15:36:15Z

commit 7e84b6216467b84cd332c8e567bf5aa113fd2f38 upstream. If ext4_setup_super() fails i.e. due to a too-high revision, the error is logged in dmesg but the fs is not mounted RO as indicated. Tested by: # mkfs.ext4 -r 4 /dev/sdb6 # mount /dev/sdb6 /mnt/test # dmesg | grep "too high" [164919.759248] EXT4-fs (sdb6): revision level too high, forcing read-only mode # grep sdb6 /proc/mounts /dev/sdb6 /mnt/test2 ext4 rw,seclabel,relatime,data=ordered 0 0 Reviewed-by: Andreas Dilger Signed-off-by: Eric Sandeen Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: fix potential NULL dereference in ext4_free_inodes_counts()

2012-06-09T15:36:15Z

commit bb3d132a24cd8bf5e7773b2d9f9baa58b07a7dae upstream. The ext4_get_group_desc() function returns NULL on error, and ext4_free_inodes_count() function dereferences it without checking. There is a check on the next line, but it's too late. Reviewed-by: Jan Kara Signed-off-by: Dan Carpenter Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman