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2012-07-20fix build errorJason Liu
Signed-off-by: Jason Liu <jason.hui@linaro.org>
2012-07-20ENGR00162198 [MX6q_ARM2]filesystem: Kernel dump if unplug SD card during bonnieTony Lin
add pointer check before accesssing to fix following problem staErXtT 3'-efms. .(.mmcblk1p2): error: remounting filesystem read-only Unable to handle kernel NULL pointer dereference at virtual address 00000010 pgd = df334000 [00000010] *pgd=71e85831, *pte=00000000, *ppte=00000000 Internal error: Oops: 17 [#1] PREEMPT SMP last sysfs file: /sys/devices/platform/sdhci-esdhc-imx.2/mmc_host/mmc1/ mmc1:b368/serial Modules linked in: ahci_platform ov3640_camera libahci libata CPU: 1 Not tainted (2.6.38-daily-00808-g43b3e87 #1) PC is at __mark_inode_dirty+0xc8/0x1b4 LR is at __mark_inode_dirty+0xb8/0x1b4 pc : [<800f7418>] lr : [<800f7408>] psr: 20000013 sp : df14dde0 ip : 00000062 fp : 00000000 r10: 003d2000 r9 : df14df38 r8 : 00000000 r7 : 4ec22acb r6 : 00000003 r5 : 00000000 r4 : e028c720 r3 : 00000001 r2 : 00000065 r1 : 804fe50c r0 : 00000001 Signed-off-by Tony Lin <tony.lin@freescale.com>
2012-07-20ENGR00069937 Community patch for Fix mount error in case of MLC flashJason Liu
Even though we don't use the OOB for MLC nand flash, we should use the bad block information to skip the bad block. Patch url: http://patchwork.ozlabs.org/linux-mtd/patch?q=mlc&filter=none&id=15477 Author:Kyungmin Park Signed-off-by: Jason Liu <r64343@freescale.com>
2012-07-20ENGR00068619 JFFS2 community fix with not use OOBJason Liu
JFFS2 community fix with not use OOB at MLC NAND, this patch is coming from the MTD community Signed-off-by: Jason Liu <r64343@freescale.com>
2012-06-17fuse: fix stat call on 32 bit platformsPavel Shilovsky
commit 45c72cd73c788dd18c8113d4a404d6b4a01decf1 upstream. Now we store attr->ino at inode->i_ino, return attr->ino at the first time and then return inode->i_ino if the attribute timeout isn't expired. That's wrong on 32 bit platforms because attr->ino is 64 bit and inode->i_ino is 32 bit in this case. Fix this by saving 64 bit ino in fuse_inode structure and returning it every time we call getattr. Also squash attr->ino into inode->i_ino explicitly. Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-10ext4: don't set i_flags in EXT4_IOC_SETFLAGSTao Ma
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 <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-10ext4: remove mb_groups before tearing down the buddy_cacheSalman Qazi
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 <sqazi@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-10ext4: add ext4_mb_unload_buddy in the error pathSalman Qazi
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 <sqazi@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-10ext4: don't trash state flags in EXT4_IOC_SETFLAGSTheodore Ts'o
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 <boyu.mt@taobao.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-10ext4: add missing save_error_info() to ext4_error()Theodore Ts'o
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 <ksumrall@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: ksumrall@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-10ext4: force ro mount if ext4_setup_super() failsEric Sandeen
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 <adilger@whamcloud.com> Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-10vfs: umount_tree() might be called on subtree that had never made itAl Viro
commit 63d37a84ab6004c235314ffd7a76c5eb28c2fae0 upstream. __mnt_make_shortterm() in there undoes the effect of __mnt_make_longterm() we'd done back when we set ->mnt_ns non-NULL; it should not be done to vfsmounts that had never gone through commit_tree() and friends. Kudos to lczerner for catching that one... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-10NFSv4: Map NFS4ERR_SHARE_DENIED into an EACCES error instead of EIOTrond Myklebust
commit fb13bfa7e1bcfdcfdece47c24b62f1a1cad957e9 upstream. If a file OPEN is denied due to a share lock, the resulting NFS4ERR_SHARE_DENIED is currently mapped to the default EIO. This patch adds a more appropriate mapping, and brings Linux into line with what Solaris 10 does. See https://bugzilla.kernel.org/show_bug.cgi?id=43286 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-10cifs: fix oops while traversing open file list (try #4)Shirish Pargaonkar
commit 2c0c2a08bed7a3b791f88d09d16ace56acb3dd98 upstream. While traversing the linked list of open file handles, if the identfied file handle is invalid, a reopen is attempted and if it fails, we resume traversing where we stopped and cifs can oops while accessing invalid next element, for list might have changed. So mark the invalid file handle and attempt reopen if no valid file handle is found in rest of the list. If reopen fails, move the invalid file handle to the end of the list and start traversing the list again from the begining. Repeat this four times before giving up and returning an error if file reopen keeps failing. Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <sfrench@us.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-01vfs: make AIO use the proper rw_verify_area() area helpersLinus Torvalds
commit a70b52ec1aaeaf60f4739edb1b422827cb6f3893 upstream. We had for some reason overlooked the AIO interface, and it didn't use the proper rw_verify_area() helper function that checks (for example) mandatory locking on the file, and that the size of the access doesn't cause us to overflow the provided offset limits etc. Instead, AIO did just the security_file_permission() thing (that rw_verify_area() also does) directly. This fixes it to do all the proper helper functions, which not only means that now mandatory file locking works with AIO too, we can actually remove lines of code. Reported-by: Manish Honap <manish_honap_vit@yahoo.co.in> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-01block: don't mark buffers beyond end of disk as mappedJeff Moyer
commit 080399aaaf3531f5b8761ec0ac30ff98891e8686 upstream. Hi, We have a bug report open where a squashfs image mounted on ppc64 would exhibit errors due to trying to read beyond the end of the disk. It can easily be reproduced by doing the following: [root@ibm-p750e-02-lp3 ~]# ls -l install.img -rw-r--r-- 1 root root 142032896 Apr 30 16:46 install.img [root@ibm-p750e-02-lp3 ~]# mount -o loop ./install.img /mnt/test [root@ibm-p750e-02-lp3 ~]# dd if=/dev/loop0 of=/dev/null dd: reading `/dev/loop0': Input/output error 277376+0 records in 277376+0 records out 142016512 bytes (142 MB) copied, 0.9465 s, 150 MB/s In dmesg, you'll find the following: squashfs: version 4.0 (2009/01/31) Phillip Lougher [ 43.106012] attempt to access beyond end of device [ 43.106029] loop0: rw=0, want=277410, limit=277408 [ 43.106039] Buffer I/O error on device loop0, logical block 138704 [ 43.106053] attempt to access beyond end of device [ 43.106057] loop0: rw=0, want=277412, limit=277408 [ 43.106061] Buffer I/O error on device loop0, logical block 138705 [ 43.106066] attempt to access beyond end of device [ 43.106070] loop0: rw=0, want=277414, limit=277408 [ 43.106073] Buffer I/O error on device loop0, logical block 138706 [ 43.106078] attempt to access beyond end of device [ 43.106081] loop0: rw=0, want=277416, limit=277408 [ 43.106085] Buffer I/O error on device loop0, logical block 138707 [ 43.106089] attempt to access beyond end of device [ 43.106093] loop0: rw=0, want=277418, limit=277408 [ 43.106096] Buffer I/O error on device loop0, logical block 138708 [ 43.106101] attempt to access beyond end of device [ 43.106104] loop0: rw=0, want=277420, limit=277408 [ 43.106108] Buffer I/O error on device loop0, logical block 138709 [ 43.106112] attempt to access beyond end of device [ 43.106116] loop0: rw=0, want=277422, limit=277408 [ 43.106120] Buffer I/O error on device loop0, logical block 138710 [ 43.106124] attempt to access beyond end of device [ 43.106128] loop0: rw=0, want=277424, limit=277408 [ 43.106131] Buffer I/O error on device loop0, logical block 138711 [ 43.106135] attempt to access beyond end of device [ 43.106139] loop0: rw=0, want=277426, limit=277408 [ 43.106143] Buffer I/O error on device loop0, logical block 138712 [ 43.106147] attempt to access beyond end of device [ 43.106151] loop0: rw=0, want=277428, limit=277408 [ 43.106154] Buffer I/O error on device loop0, logical block 138713 [ 43.106158] attempt to access beyond end of device [ 43.106162] loop0: rw=0, want=277430, limit=277408 [ 43.106166] attempt to access beyond end of device [ 43.106169] loop0: rw=0, want=277432, limit=277408 ... [ 43.106307] attempt to access beyond end of device [ 43.106311] loop0: rw=0, want=277470, limit=2774 Squashfs manages to read in the end block(s) of the disk during the mount operation. Then, when dd reads the block device, it leads to block_read_full_page being called with buffers that are beyond end of disk, but are marked as mapped. Thus, it would end up submitting read I/O against them, resulting in the errors mentioned above. I fixed the problem by modifying init_page_buffers to only set the buffer mapped if it fell inside of i_size. Cheers, Jeff Signed-off-by: Jeff Moyer <jmoyer@redhat.com> Acked-by: Nick Piggin <npiggin@kernel.dk> -- Changes from v1->v2: re-used max_block, as suggested by Nick Piggin. Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-21wake up s_wait_unfrozen when ->freeze_fs failsKazuya Mio
commit e1616300a20c80396109c1cf013ba9a36055a3da upstream. dd slept infinitely when fsfeeze failed because of EIO. To fix this problem, if ->freeze_fs fails, freeze_super() wakes up the tasks waiting for the filesystem to become unfrozen. When s_frozen isn't SB_UNFROZEN in __generic_file_aio_write(), the function sleeps until FITHAW ioctl wakes up s_wait_unfrozen. However, if ->freeze_fs fails, s_frozen is set to SB_UNFROZEN and then freeze_super() returns an error number. In this case, FITHAW ioctl returns EINVAL because s_frozen is already SB_UNFROZEN. There is no way to wake up s_wait_unfrozen, so __generic_file_aio_write() sleeps infinitely. Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-21ext4: fix error handling on inode bitmap corruptionJan Kara
commit acd6ad83517639e8f09a8c5525b1dccd81cd2a10 upstream. When insert_inode_locked() fails in ext4_new_inode() it most likely means inode bitmap got corrupted and we allocated again inode which is already in use. Also doing unlock_new_inode() during error recovery is wrong since the inode does not have I_NEW set. Fix the problem by jumping to fail: (instead of fail_drop:) which declares filesystem error and does not call unlock_new_inode(). Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-21ext3: Fix error handling on inode bitmap corruptionJan Kara
commit 1415dd8705394399d59a3df1ab48d149e1e41e77 upstream. When insert_inode_locked() fails in ext3_new_inode() it most likely means inode bitmap got corrupted and we allocated again inode which is already in use. Also doing unlock_new_inode() during error recovery is wrong since inode does not have I_NEW set. Fix the problem by jumping to fail: (instead of fail_drop:) which declares filesystem error and does not call unlock_new_inode(). Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-21NFSv4: Revalidate uid/gid after openJonathan Nieder
This is a shorter (and more appropriate for stable kernels) analog to the following upstream commit: commit 6926afd1925a54a13684ebe05987868890665e2b Author: Trond Myklebust <Trond.Myklebust@netapp.com> Date: Sat Jan 7 13:22:46 2012 -0500 NFSv4: Save the owner/group name string when doing open ...so that we can do the uid/gid mapping outside the asynchronous RPC context. This fixes a bug in the current NFSv4 atomic open code where the client isn't able to determine what the true uid/gid fields of the file are, (because the asynchronous nature of the OPEN call denies it the ability to do an upcall) and so fills them with default values, marking the inode as needing revalidation. Unfortunately, in some cases, the VFS will do some additional sanity checks on the file, and may override the server's decision to allow the open because it sees the wrong owner/group fields. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Without this patch, logging into two different machines with home directories mounted over NFS4 and then running "vim" and typing ":q" in each reliably produces the following error on the second machine: E137: Viminfo file is not writable: /users/system/rtheys/.viminfo This regression was introduced by 80e52aced138 ("NFSv4: Don't do idmapper upcalls for asynchronous RPC calls", merged during the 2.6.32 cycle) --- after the OPEN call, .viminfo has the default values for st_uid and st_gid (0xfffffffe) cached because we do not want to let rpciod wait for an idmapper upcall to fill them in. The fix used in mainline is to save the owner and group as strings and perform the upcall in _nfs4_proc_open outside the rpciod context, which takes about 600 lines. For stable, we can do something similar with a one-liner: make open check for the stale fields and make a (synchronous) GETATTR call to fill them when needed. Trond dictated the patch, I typed it in, and Rik tested it. Addresses http://bugs.debian.org/659111 and https://bugzilla.redhat.com/789298 Reported-by: Rik Theys <Rik.Theys@esat.kuleuven.be> Explained-by: David Flyn <davidf@rd.bbc.co.uk> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Tested-by: Rik Theys <Rik.Theys@esat.kuleuven.be> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-21ext4: avoid deadlock on sync-mounted FS w/o journalEric Sandeen
commit c1bb05a657fb3d8c6179a4ef7980261fae4521d7 upstream. Processes hang forever on a sync-mounted ext2 file system that is mounted with the ext4 module (default in Fedora 16). I can reproduce this reliably by mounting an ext2 partition with "-o sync" and opening a new file an that partition with vim. vim will hang in "D" state forever. The same happens on ext4 without a journal. I am attaching a small patch here that solves this issue for me. In the sync mounted case without a journal, ext4_handle_dirty_metadata() may call sync_dirty_buffer(), which can't be called with buffer lock held. Also move mb_cache_entry_release inside lock to avoid race fixed previously by 8a2bfdcb ext[34]: EA block reference count racing fix Note too that ext2 fixed this same problem in 2006 with b2f49033 [PATCH] fix deadlock in ext2 Signed-off-by: Martin.Wilck@ts.fujitsu.com [sandeen@redhat.com: move mb_cache_entry_release before unlock, edit commit msg] Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-21jffs2: Fix lock acquisition order bug in gc pathJosh Cartwright
commit 226bb7df3d22bcf4a1c0fe8206c80cc427498eae upstream. The locking policy is such that the erase_complete_block spinlock is nested within the alloc_sem mutex. This fixes a case in which the acquisition order was erroneously reversed. This issue was caught by the following lockdep splat: ======================================================= [ INFO: possible circular locking dependency detected ] 3.0.5 #1 ------------------------------------------------------- jffs2_gcd_mtd6/299 is trying to acquire lock: (&c->alloc_sem){+.+.+.}, at: [<c01f7714>] jffs2_garbage_collect_pass+0x314/0x890 but task is already holding lock: (&(&c->erase_completion_lock)->rlock){+.+...}, at: [<c01f7708>] jffs2_garbage_collect_pass+0x308/0x890 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&(&c->erase_completion_lock)->rlock){+.+...}: [<c008bec4>] validate_chain+0xe6c/0x10bc [<c008c660>] __lock_acquire+0x54c/0xba4 [<c008d240>] lock_acquire+0xa4/0x114 [<c046780c>] _raw_spin_lock+0x3c/0x4c [<c01f744c>] jffs2_garbage_collect_pass+0x4c/0x890 [<c01f937c>] jffs2_garbage_collect_thread+0x1b4/0x1cc [<c0071a68>] kthread+0x98/0xa0 [<c000f264>] kernel_thread_exit+0x0/0x8 -> #0 (&c->alloc_sem){+.+.+.}: [<c008ad2c>] print_circular_bug+0x70/0x2c4 [<c008c08c>] validate_chain+0x1034/0x10bc [<c008c660>] __lock_acquire+0x54c/0xba4 [<c008d240>] lock_acquire+0xa4/0x114 [<c0466628>] mutex_lock_nested+0x74/0x33c [<c01f7714>] jffs2_garbage_collect_pass+0x314/0x890 [<c01f937c>] jffs2_garbage_collect_thread+0x1b4/0x1cc [<c0071a68>] kthread+0x98/0xa0 [<c000f264>] kernel_thread_exit+0x0/0x8 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&c->erase_completion_lock)->rlock); lock(&c->alloc_sem); lock(&(&c->erase_completion_lock)->rlock); lock(&c->alloc_sem); *** DEADLOCK *** 1 lock held by jffs2_gcd_mtd6/299: #0: (&(&c->erase_completion_lock)->rlock){+.+...}, at: [<c01f7708>] jffs2_garbage_collect_pass+0x308/0x890 stack backtrace: [<c00155dc>] (unwind_backtrace+0x0/0x100) from [<c0463dc0>] (dump_stack+0x20/0x24) [<c0463dc0>] (dump_stack+0x20/0x24) from [<c008ae84>] (print_circular_bug+0x1c8/0x2c4) [<c008ae84>] (print_circular_bug+0x1c8/0x2c4) from [<c008c08c>] (validate_chain+0x1034/0x10bc) [<c008c08c>] (validate_chain+0x1034/0x10bc) from [<c008c660>] (__lock_acquire+0x54c/0xba4) [<c008c660>] (__lock_acquire+0x54c/0xba4) from [<c008d240>] (lock_acquire+0xa4/0x114) [<c008d240>] (lock_acquire+0xa4/0x114) from [<c0466628>] (mutex_lock_nested+0x74/0x33c) [<c0466628>] (mutex_lock_nested+0x74/0x33c) from [<c01f7714>] (jffs2_garbage_collect_pass+0x314/0x890) [<c01f7714>] (jffs2_garbage_collect_pass+0x314/0x890) from [<c01f937c>] (jffs2_garbage_collect_thread+0x1b4/0x1cc) [<c01f937c>] (jffs2_garbage_collect_thread+0x1b4/0x1cc) from [<c0071a68>] (kthread+0x98/0xa0) [<c0071a68>] (kthread+0x98/0xa0) from [<c000f264>] (kernel_thread_exit+0x0/0x8) This was introduce in '81cfc9f jffs2: Fix serious write stall due to erase'. Signed-off-by: Josh Cartwright <joshc@linux.com> Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07hfsplus: Fix potential buffer overflowsGreg Kroah-Hartman
commit 6f24f892871acc47b40dd594c63606a17c714f77 upstream. Commit ec81aecb2966 ("hfs: fix a potential buffer overflow") fixed a few potential buffer overflows in the hfs filesystem. But as Timo Warns pointed out, these changes also need to be made on the hfsplus filesystem as well. Reported-by: Timo Warns <warns@pre-sense.de> Acked-by: WANG Cong <amwang@redhat.com> Cc: Alexey Khoroshilov <khoroshilov@ispras.ru> Cc: Miklos Szeredi <mszeredi@suse.cz> Cc: Sage Weil <sage@newdream.net> Cc: Eugene Teo <eteo@redhat.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Dave Anderson <anderson@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-07autofs: make the autofsv5 packet file descriptor use a packetized pipeLinus Torvalds
commit 64f371bc3107e69efce563a3d0f0e6880de0d537 upstream. The autofs packet size has had a very unfortunate size problem on x86: because the alignment of 'u64' differs in 32-bit and 64-bit modes, and because the packet data was not 8-byte aligned, the size of the autofsv5 packet structure differed between 32-bit and 64-bit modes despite looking otherwise identical (300 vs 304 bytes respectively). We first fixed that up by making the 64-bit compat mode know about this problem in commit a32744d4abae ("autofs: work around unhappy compat problem on x86-64"), and that made a 32-bit 'systemd' work happily on a 64-bit kernel because everything then worked the same way as on a 32-bit kernel. But it turned out that 'automount' had actually known and worked around this problem in user space, so fixing the kernel to do the proper 32-bit compatibility handling actually *broke* 32-bit automount on a 64-bit kernel, because it knew that the packet sizes were wrong and expected those incorrect sizes. As a result, we ended up reverting that compatibility mode fix, and thus breaking systemd again, in commit fcbf94b9dedd. With both automount and systemd doing a single read() system call, and verifying that they get *exactly* the size they expect but using different sizes, it seemed that fixing one of them inevitably seemed to break the other. At one point, a patch I seriously considered applying from Michael Tokarev did a "strcmp()" to see if it was automount that was doing the operation. Ugly, ugly. However, a prettier solution exists now thanks to the packetized pipe mode. By marking the communication pipe as being packetized (by simply setting the O_DIRECT flag), we can always just write the bigger packet size, and if user-space does a smaller read, it will just get that partial end result and the extra alignment padding will simply be thrown away. This makes both automount and systemd happy, since they now get the size they asked for, and the kernel side of autofs simply no longer needs to care - it could pad out the packet arbitrarily. Of course, if there is some *other* user of autofs (please, please, please tell me it ain't so - and we haven't heard of any) that tries to read the packets with multiple writes, that other user will now be broken - the whole point of the packetized mode is that one system call gets exactly one packet, and you cannot read a packet in pieces. Tested-by: Michael Tokarev <mjt@tls.msk.ru> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: David Miller <davem@davemloft.net> Cc: Ian Kent <raven@themaw.net> Cc: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07pipes: add a "packetized pipe" mode for writingLinus Torvalds
commit 9883035ae7edef3ec62ad215611cb8e17d6a1a5d upstream. The actual internal pipe implementation is already really about individual packets (called "pipe buffers"), and this simply exposes that as a special packetized mode. When we are in the packetized mode (marked by O_DIRECT as suggested by Alan Cox), a write() on a pipe will not merge the new data with previous writes, so each write will get a pipe buffer of its own. The pipe buffer is then marked with the PIPE_BUF_FLAG_PACKET flag, which in turn will tell the reader side to break the read at that boundary (and throw away any partial packet contents that do not fit in the read buffer). End result: as long as you do writes less than PIPE_BUF in size (so that the pipe doesn't have to split them up), you can now treat the pipe as a packet interface, where each read() system call will read one packet at a time. You can just use a sufficiently big read buffer (PIPE_BUF is sufficient, since bigger than that doesn't guarantee atomicity anyway), and the return value of the read() will naturally give you the size of the packet. NOTE! We do not support zero-sized packets, and zero-sized reads and writes to a pipe continue to be no-ops. Also note that big packets will currently be split at write time, but that the size at which that happens is not really specified (except that it's bigger than PIPE_BUF). Currently that limit is the system page size, but we might want to explicitly support bigger packets some day. The main user for this is going to be the autofs packet interface, allowing us to stop having to care so deeply about exact packet sizes (which have had bugs with 32/64-bit compatibility modes). But user space can create packetized pipes with "pipe2(fd, O_DIRECT)", which will fail with an EINVAL on kernels that do not support this interface. Tested-by: Michael Tokarev <mjt@tls.msk.ru> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: David Miller <davem@davemloft.net> Cc: Ian Kent <raven@themaw.net> Cc: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07nfsd: fix error values returned by nfsd4_lockt() when nfsd_open() failsAl Viro
commit 04da6e9d63427b2d0fd04766712200c250b3278f upstream. nfsd_open() already returns an NFS error value; only vfs_test_lock() result needs to be fed through nfserrno(). Broken by commit 55ef12 (nfsd: Ensure nfsv4 calls the underlying filesystem on LOCKT) three years ago... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07nfsd: fix b0rken error value for setattr on read-only mountAl Viro
commit 96f6f98501196d46ce52c2697dd758d9300c63f5 upstream. ..._want_write() returns -EROFS on failure, _not_ an NFS error value. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07Revert "autofs: work around unhappy compat problem on x86-64"Linus Torvalds
commit fcbf94b9dedd2ce08e798a99aafc94fec8668161 upstream. This reverts commit a32744d4abae24572eff7269bc17895c41bd0085. While that commit was technically the right thing to do, and made the x86-64 compat mode work identically to native 32-bit mode (and thus fixing the problem with a 32-bit systemd install on a 64-bit kernel), it turns out that the automount binaries had workarounds for this compat problem. Now, the workarounds are disgusting: doing an "uname()" to find out the architecture of the kernel, and then comparing it for the 64-bit cases and fixing up the size of the read() in automount for those. And they were confused: it's not actually a generic 64-bit issue at all, it's very much tied to just x86-64, which has different alignment for an 'u64' in 64-bit mode than in 32-bit mode. But the end result is that fixing the compat layer actually breaks the case of a 32-bit automount on a x86-64 kernel. There are various approaches to fix this (including just doing a "strcmp()" on current->comm and comparing it to "automount"), but I think that I will do the one that teaches pipes about a special "packet mode", which will allow user space to not have to care too deeply about the padding at the end of the autofs packet. That change will make the compat workaround unnecessary, so let's revert it first, and get automount working again in compat mode. The packetized pipes will then fix autofs for systemd. Reported-and-requested-by: Michael Tokarev <mjt@tls.msk.ru> Cc: Ian Kent <raven@themaw.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07NFSv4: Ensure that we check lock exclusive/shared type against open modesTrond Myklebust
commit 55725513b5ef9d462aa3e18527658a0362aaae83 upstream. Since we may be simulating flock() locks using NFS byte range locks, we can't rely on the VFS having checked the file open mode for us. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07NFSv4: Ensure that the LOCK code sets exception->inodeTrond Myklebust
commit 05ffe24f5290dc095f98fbaf84afe51ef404ccc5 upstream. All callers of nfs4_handle_exception() that need to handle NFS4ERR_OPENMODE correctly should set exception->inode Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-07nfs: Enclose hostname in brackets when needed in nfs_do_root_mountJan Kara
commit 98a2139f4f4d7b5fcc3a54c7fddbe88612abed20 upstream. When hostname contains colon (e.g. when it is an IPv6 address) it needs to be enclosed in brackets to make parsing of NFS device string possible. Fix nfs_do_root_mount() to enclose hostname properly when needed. NFS code actually does not need this as it does not parse the string passed by nfs_do_root_mount() but the device string is exposed to userspace in /proc/mounts. CC: Josh Boyer <jwboyer@redhat.com> CC: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27tcp: allow splice() to build full TSO packetsEric Dumazet
[ This combines upstream commit 2f53384424251c06038ae612e56231b96ab610ee and the follow-on bug fix commit 35f9c09fe9c72eb8ca2b8e89a593e1c151f28fc2 ] vmsplice()/splice(pipe, socket) call do_tcp_sendpages() one page at a time, adding at most 4096 bytes to an skb. (assuming PAGE_SIZE=4096) The call to tcp_push() at the end of do_tcp_sendpages() forces an immediate xmit when pipe is not already filled, and tso_fragment() try to split these skb to MSS multiples. 4096 bytes are usually split in a skb with 2 MSS, and a remaining sub-mss skb (assuming MTU=1500) This makes slow start suboptimal because many small frames are sent to qdisc/driver layers instead of big ones (constrained by cwnd and packets in flight of course) In fact, applications using sendmsg() (adding an additional memory copy) instead of vmsplice()/splice()/sendfile() are a bit faster because of this anomaly, especially if serving small files in environments with large initial [c]wnd. Call tcp_push() only if MSG_MORE is not set in the flags parameter. This bit is automatically provided by splice() internals but for the last page, or on all pages if user specified SPLICE_F_MORE splice() flag. In some workloads, this can reduce number of sent logical packets by an order of magnitude, making zero-copy TCP actually faster than one-copy :) Reported-by: Tom Herbert <therbert@google.com> Cc: Nandita Dukkipati <nanditad@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: H.K. Jerry Chu <hkchu@google.com> Cc: Maciej Żenczykowski <maze@google.com> Cc: Mahesh Bandewar <maheshb@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27lockd: fix the endianness bugAl Viro
commit e847469bf77a1d339274074ed068d461f0c872bc upstream. comparing be32 values for < is not doing the right thing... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27ocfs2: ->e_leaf_clusters endianness breakageAl Viro
commit 72094e43e3af5020510f920321d71f1798fa896d upstream. le16, not le32... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27ocfs2: ->rl_count endianness breakageAl Viro
commit 28748b325dc2d730ccc312830a91c4ae0c0d9379 upstream. le16, not le32... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27ocfs: ->rl_used breakage on big-endianAl Viro
commit e1bf4cc620fd143766ddfcee3b004a1d1bb34fd0 upstream. it's le16, not le32 or le64... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27ocfs2: ->l_next_free_req breakage on big-endianAl Viro
commit 3a251f04fe97c3d335b745c98e4b377e3c3899f2 upstream. It's le16, not le32... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27btrfs: btrfs_root_readonly() broken on big-endianAl Viro
commit 6ed3cf2cdfce4c9f1d73171bd3f27d9cb77b734e upstream. ->root_flags is __le64 and all accesses to it go through the helpers that do proper conversions. Except for btrfs_root_readonly(), which checks bit 0 as in host-endian... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Chris Mason <chris.mason@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27nfsd: fix compose_entry_fh() failure exitsAl Viro
commit efe39651f08813180f37dc508d950fc7d92b29a8 upstream. Restore the original logics ("fail on mountpoints, negatives and in case of fh_compose() failures"). Since commit 8177e (nfsd: clean up readdirplus encoding) that got broken - rv = fh_compose(fhp, exp, dchild, &cd->fh); if (rv) goto out; if (!dchild->d_inode) goto out; rv = 0; out: is equivalent to rv = fh_compose(fhp, exp, dchild, &cd->fh); out: and the second check has no effect whatsoever... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: "J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27Don't limit non-nested epoll pathsJason Baron
commit 93dc6107a76daed81c07f50215fa6ae77691634f upstream. Commit 28d82dc1c4ed ("epoll: limit paths") that I did to limit the number of possible wakeup paths in epoll is causing a few applications to longer work (dovecot for one). The original patch is really about limiting the amount of epoll nesting (since epoll fds can be attached to other fds). Thus, we probably can allow an unlimited number of paths of depth 1. My current patch limits it at 1000. And enforce the limits on paths that have a greater depth. This is captured in: https://bugzilla.redhat.com/show_bug.cgi?id=681578 Signed-off-by: Jason Baron <jbaron@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27ext4: fix endianness breakage in ext4_split_extent_at()Al Viro
commit af1584f570b19b0285e4402a0b54731495d31784 upstream. ->ee_len is __le16, so assigning cpu_to_le32() to it is going to do Bad Things(tm) on big-endian hosts... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Ted Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-27jbd2: use GFP_NOFS for blkdev_issue_flushShaohua Li
commit 99aa78466777083255b876293e9e83dec7cd809a upstream. flush request is issued in transaction commit code path, so looks using GFP_KERNEL to allocate memory for flush request bio falls into the classic deadlock issue. I saw btrfs and dm get it right, but ext4, xfs and md are using GFP. Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02lockd: fix arg parsing for grace_period and timeout.NeilBrown
commit de5b8e8e047534aac6bc9803f96e7257436aef9c upstream. If you try to set grace_period or timeout via a module parameter to lockd, and do this on a big-endian machine where sizeof(int) != sizeof(unsigned long) it won't work. This number given will be effectively shifted right by the difference in those two sizes. So cast kp->arg properly to get correct result. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02xfs: Fix oops on IO error during xlog_recover_process_iunlinks()Jan Kara
commit d97d32edcd732110758799ae60af725e5110b3dc upstream. When an IO error happens during inode deletion run from xlog_recover_process_iunlinks() filesystem gets shutdown. Thus any subsequent attempt to read buffers fails. Code in xlog_recover_process_iunlinks() does not count with the fact that read of a buffer which was read a while ago can really fail which results in the oops on agi = XFS_BUF_TO_AGI(agibp); Fix the problem by cleaning up the buffer handling in xlog_recover_process_iunlinks() as suggested by Dave Chinner. We release buffer lock but keep buffer reference to AG buffer. That is enough for buffer to stay pinned in memory and we don't have to call xfs_read_agi() all the time. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02udf: Fix deadlock in udf_release_file()Jan Kara
commit a0391a3ae91d301c0e59368531a4de5f0b122bcf upstream. udf_release_file() can be called from munmap() path with mmap_sem held. Thus we cannot take i_mutex there because that ranks above mmap_sem. Luckily, i_mutex is not needed in udf_release_file() anymore since protection by i_data_sem is enough to protect from races with write and truncate. Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Reviewed-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02vfs: fix d_ancestor() case in d_materialize_uniqueMichel Lespinasse
commit b18dafc86bb879d2f38a1743985d7ceb283c2f4d upstream. In d_materialise_unique() there are 3 subcases to the 'aliased dentry' case; in two subcases the inode i_lock is properly released but this does not occur in the -ELOOP subcase. This seems to have been introduced by commit 1836750115f2 ("fix loop checks in d_materialise_unique()"). Signed-off-by: Michel Lespinasse <walken@google.com> [ Added a comment, and moved the unlock to where we generate the -ELOOP, which seems to be more natural. You probably can't actually trigger this without a buggy network file server - d_materialize_unique() is for finding aliases on non-local filesystems, and the d_ancestor() case is for a hardlinked directory loop. But we should be robust in the case of such buggy servers anyway. ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02ext4: check for zero length extentTheodore Ts'o
commit 31d4f3a2f3c73f279ff96a7135d7202ef6833f12 upstream. Explicitly test for an extent whose length is zero, and flag that as a corrupted extent. This avoids a kernel BUG_ON assertion failure. Tested: Without this patch, the file system image found in tests/f_ext_zero_len/image.gz in the latest e2fsprogs sources causes a kernel panic. With this patch, an ext4 file system error is noted instead, and the file system is marked as being corrupted. https://bugzilla.kernel.org/show_bug.cgi?id=42859 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02ext4: ignore EXT4_INODE_JOURNAL_DATA flag with delallocLukas Czerner
commit 3d2b158262826e8b75bbbfb7b97010838dd92ac7 upstream. Ext4 does not support data journalling with delayed allocation enabled. We even do not allow to mount the file system with delayed allocation and data journalling enabled, however it can be set via FS_IOC_SETFLAGS so we can hit the inode with EXT4_INODE_JOURNAL_DATA set even on file system mounted with delayed allocation (default) and that's where problem arises. The easies way to reproduce this problem is with the following set of commands: mkfs.ext4 /dev/sdd mount /dev/sdd /mnt/test1 dd if=/dev/zero of=/mnt/test1/file bs=1M count=4 chattr +j /mnt/test1/file dd if=/dev/zero of=/mnt/test1/file bs=1M count=4 conv=notrunc chattr -j /mnt/test1/file Additionally it can be reproduced quite reliably with xfstests 272 and 269. In fact the above reproducer is a part of test 272. To fix this we should ignore the EXT4_INODE_JOURNAL_DATA inode flag if the file system is mounted with delayed allocation. This can be easily done by fixing ext4_should_*_data() functions do ignore data journal flag when delalloc is set (suggested by Ted). We also have to set the appropriate address space operations for the inode (again, ignoring data journal flag if delalloc enabled). Additionally this commit introduces ext4_inode_journal_mode() function because ext4_should_*_data() has already had a lot of common code and this change is putting it all into one function so it is easier to read. Successfully tested with xfstests in following configurations: delalloc + data=ordered delalloc + data=writeback data=journal nodelalloc + data=ordered nodelalloc + data=writeback nodelalloc + data=journal Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02jbd2: clear BH_Delay & BH_Unwritten in journal_unmap_bufferEric Sandeen
commit 15291164b22a357cb211b618adfef4fa82fc0de3 upstream. journal_unmap_buffer()'s zap_buffer: code clears a lot of buffer head state ala discard_buffer(), but does not touch _Delay or _Unwritten as discard_buffer() does. This can be problematic in some areas of the ext4 code which assume that if they have found a buffer marked unwritten or delay, then it's a live one. Perhaps those spots should check whether it is mapped as well, but if jbd2 is going to tear down a buffer, let's really tear it down completely. Without this I get some fsx failures on sub-page-block filesystems up until v3.2, at which point 4e96b2dbbf1d7e81f22047a50f862555a6cb87cb and 189e868fa8fdca702eb9db9d8afc46b5cb9144c9 make the failures go away, because buried within that large change is some more flag clearing. I still think it's worth doing in jbd2, since ->invalidatepage leads here directly, and it's the right place to clear away these flags. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-02ext4: flush any pending end_io requests before DIO reads w/dioread_nolockJiaying Zhang
commit dccaf33fa37a1bc5d651baeb3bfeb6becb86597b upstream. (backported to 3.0 by mjt) There is a race between ext4 buffer write and direct_IO read with dioread_nolock mount option enabled. The problem is that we clear PageWriteback flag during end_io time but will do uninitialized-to-initialized extent conversion later with dioread_nolock. If an O_direct read request comes in during this period, ext4 will return zero instead of the recently written data. This patch checks whether there are any pending uninitialized-to-initialized extent conversion requests before doing O_direct read to close the race. Note that this is just a bandaid fix. The fundamental issue is that we clear PageWriteback flag before we really complete an IO, which is problem-prone. To fix the fundamental issue, we may need to implement an extent tree cache that we can use to look up pending to-be-converted extents. Signed-off-by: Jiaying Zhang <jiayingz@google.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>