linux/fs, branch v3.4.44

ext4: fix Kconfig documentation for CONFIG_EXT4_DEBUG

2013-05-08T02:51:57Z

commit 7f3e3c7cfcec148ccca9c0dd2dbfd7b00b7ac10f upstream. Fox the Kconfig documentation for CONFIG_EXT4_DEBUG to match the change made by commit a0b30c1229: ext4: use module parameters instead of debugfs for mballoc_debug Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: fix online resizing for ext3-compat file systems

2013-05-08T02:51:57Z

commit c5c72d814cf0f650010337c73638b25e6d14d2d4 upstream. Commit fb0a387dcdc restricts block allocations for indirect-mapped files to block groups less than s_blockfile_groups. However, the online resizing code wasn't setting s_blockfile_groups, so the newly added block groups were not available for non-extent mapped files. Reported-by: Eric Sandeen Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext4: fix journal callback list traversal

2013-05-08T02:51:57Z

commit 5d3ee20855e28169d711b394857ee608a5023094 upstream. It is incorrect to use list_for_each_entry_safe() for journal callback traversial because ->next may be removed by other task: ->ext4_mb_free_metadata() ->ext4_mb_free_metadata() ->ext4_journal_callback_del() This results in the following issue: WARNING: at lib/list_debug.c:62 __list_del_entry+0x1c0/0x250() Hardware name: list_del corruption. prev->next should be ffff88019a4ec198, but was 6b6b6b6b6b6b6b6b Modules linked in: cpufreq_ondemand acpi_cpufreq freq_table mperf coretemp kvm_intel kvm crc32c_intel ghash_clmulni_intel microcode sg xhci_hcd button sd_mod crc_t10dif aesni_intel ablk_helper cryptd lrw aes_x86_64 xts gf128mul ahci libahci pata_acpi ata_generic dm_mirror dm_region_hash dm_log dm_mod Pid: 16400, comm: jbd2/dm-1-8 Tainted: G W 3.8.0-rc3+ #107 Call Trace: [] warn_slowpath_common+0xad/0xf0 [] warn_slowpath_fmt+0x46/0x50 [] ? ext4_journal_commit_callback+0x99/0xc0 [] __list_del_entry+0x1c0/0x250 [] ext4_journal_commit_callback+0x6f/0xc0 [] jbd2_journal_commit_transaction+0x23a6/0x2570 [] ? try_to_del_timer_sync+0x82/0xa0 [] ? del_timer_sync+0x91/0x1e0 [] kjournald2+0x19f/0x6a0 [] ? wake_up_bit+0x40/0x40 [] ? bit_spin_lock+0x80/0x80 [] kthread+0x10e/0x120 [] ? __init_kthread_worker+0x70/0x70 [] ret_from_fork+0x7c/0xb0 [] ? __init_kthread_worker+0x70/0x70 This patch fix the issue as follows: - ext4_journal_commit_callback() make list truly traversial safe simply by always starting from list_head - fix race between two ext4_journal_callback_del() and ext4_journal_callback_try_del() Signed-off-by: Dmitry Monakhov Signed-off-by: "Theodore Ts'o" Reviewed-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

jbd2: fix race between jbd2_journal_remove_checkpoint and ->j_commit_callback

2013-05-08T02:51:57Z

commit 794446c6946513c684d448205fbd76fa35f38b72 upstream. The following race is possible: [kjournald2] other_task jbd2_journal_commit_transaction() j_state = T_FINISHED; spin_unlock(&journal->j_list_lock); ->jbd2_journal_remove_checkpoint() ->jbd2_journal_free_transaction(); ->kmem_cache_free(transaction) ->j_commit_callback(journal, transaction); -> USE_AFTER_FREE WARNING: at lib/list_debug.c:62 __list_del_entry+0x1c0/0x250() Hardware name: list_del corruption. prev->next should be ffff88019a4ec198, but was 6b6b6b6b6b6b6b6b Modules linked in: cpufreq_ondemand acpi_cpufreq freq_table mperf coretemp kvm_intel kvm crc32c_intel ghash_clmulni_intel microcode sg xhci_hcd button sd_mod crc_t10dif aesni_intel ablk_helper cryptd lrw aes_x86_64 xts gf128mul ahci libahci pata_acpi ata_generic dm_mirror dm_region_hash dm_log dm_mod Pid: 16400, comm: jbd2/dm-1-8 Tainted: G W 3.8.0-rc3+ #107 Call Trace: [] warn_slowpath_common+0xad/0xf0 [] warn_slowpath_fmt+0x46/0x50 [] ? ext4_journal_commit_callback+0x99/0xc0 [] __list_del_entry+0x1c0/0x250 [] ext4_journal_commit_callback+0x6f/0xc0 [] jbd2_journal_commit_transaction+0x23a6/0x2570 [] ? try_to_del_timer_sync+0x82/0xa0 [] ? del_timer_sync+0x91/0x1e0 [] kjournald2+0x19f/0x6a0 [] ? wake_up_bit+0x40/0x40 [] ? bit_spin_lock+0x80/0x80 [] kthread+0x10e/0x120 [] ? __init_kthread_worker+0x70/0x70 [] ret_from_fork+0x7c/0xb0 [] ? __init_kthread_worker+0x70/0x70 In order to demonstrace this issue one should mount ext4 with mount -o discard option on SSD disk. This makes callback longer and race window becomes wider. In order to fix this we should mark transaction as finished only after callbacks have completed Signed-off-by: Dmitry Monakhov Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

nfsd: Decode and send 64bit time values

2013-05-08T02:51:56Z

commit bf8d909705e9d9bac31d9b8eac6734d2b51332a7 upstream. The seconds field of an nfstime4 structure is 64bit, but we are assuming that the first 32bits are zero-filled. So if the client tries to set atime to a value before the epoch (touch -t 196001010101), then the server will save the wrong value on disk. Signed-off-by: Bryan Schumaker Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman

nfsd4: don't close read-write opens too soon

2013-05-08T02:51:56Z

commit 0c7c3e67ab91ec6caa44bdf1fc89a48012ceb0c5 upstream. Don't actually close any opens until we don't need them at all. This means being left with write access when it's not really necessary, but that's better than putting a file that might still have posix locks held on it, as we have been. Reported-by: Toralf Förster Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman

NFSv4: Handle NFS4ERR_DELAY and NFS4ERR_GRACE in nfs4_open_delegation_recall

2013-05-08T02:51:56Z

commit 8b6cc4d6f841d31f72fe7478453759166d366274 upstream. A server shouldn't normally return NFS4ERR_GRACE if the client holds a delegation, since no conflicting lock reclaims can be granted, however the spec does not require the server to grant the open in this instance Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

LOCKD: Ensure that nlmclnt_block resets block->b_status after a server reboot

2013-05-08T02:51:56Z

commit 1dfd89af8697a299e7982ae740d4695ecd917eef upstream. After a server reboot, the reclaimer thread will recover all the existing locks. For locks that are blocked, however, it will change the value of block->b_status to nlm_lck_denied_grace_period in order to signal that they need to wake up and resend the original blocking lock request. Due to a bug, however, the block->b_status never gets reset after the blocked locks have been woken up, and so the process goes into an infinite loop of resends until the blocked lock is satisfied. Reported-by: Marc Eshel Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman

fs/dcache.c: add cond_resched() to shrink_dcache_parent()

2013-05-08T02:51:56Z

commit 421348f1ca0bf17769dee0aed4d991845ae0536d upstream. Call cond_resched() in shrink_dcache_parent() to maintain interactivity. Before this patch: void shrink_dcache_parent(struct dentry * parent) { while ((found = select_parent(parent, &dispose)) != 0) shrink_dentry_list(&dispose); } select_parent() populates the dispose list with dentries which shrink_dentry_list() then deletes. select_parent() carefully uses need_resched() to avoid doing too much work at once. But neither shrink_dcache_parent() nor its called functions call cond_resched(). So once need_resched() is set select_parent() will return single dentry dispose list which is then deleted by shrink_dentry_list(). This is inefficient when there are a lot of dentry to process. This can cause softlockup and hurts interactivity on non preemptable kernels. This change adds cond_resched() in shrink_dcache_parent(). The benefit of this is that need_resched() is quickly cleared so that future calls to select_parent() are able to efficiently return a big batch of dentry. These additional cond_resched() do not seem to impact performance, at least for the workload below. Here is a program which can cause soft lockup if other system activity sets need_resched(). int main() { struct rlimit rlim; int i; int f[100000]; char buf[20]; struct timeval t1, t2; double diff; /* cleanup past run */ system("rm -rf x"); /* boost nfile rlimit */ rlim.rlim_cur = 200000; rlim.rlim_max = 200000; if (setrlimit(RLIMIT_NOFILE, &rlim)) err(1, "setrlimit"); /* make directory for files */ if (mkdir("x", 0700)) err(1, "mkdir"); if (gettimeofday(&t1, NULL)) err(1, "gettimeofday"); /* populate directory with open files */ for (i = 0; i < 100000; i++) { snprintf(buf, sizeof(buf), "x/%d", i); f[i] = open(buf, O_CREAT); if (f[i] == -1) err(1, "open"); } /* close some of the files */ for (i = 0; i < 85000; i++) close(f[i]); /* unlink all files, even open ones */ system("rm -rf x"); if (gettimeofday(&t2, NULL)) err(1, "gettimeofday"); diff = (((double)t2.tv_sec * 1000000 + t2.tv_usec) - ((double)t1.tv_sec * 1000000 + t1.tv_usec)); printf("done: %g elapsed\n", diff/1e6); return 0; } Signed-off-by: Greg Thelen Signed-off-by: Dave Chinner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

mm: allow arch code to control the user page table ceiling

2013-05-08T02:51:55Z

commit 6ee8630e02be6dd89926ca0fbc21af68b23dc087 upstream. On architectures where a pgd entry may be shared between user and kernel (e.g. ARM+LPAE), freeing page tables needs a ceiling other than 0. This patch introduces a generic USER_PGTABLES_CEILING that arch code can override. It is the responsibility of the arch code setting the ceiling to ensure the complete freeing of the page tables (usually in pgd_free()). [catalin.marinas@arm.com: commit log; shift_arg_pages(), asm-generic/pgtables.h changes] Signed-off-by: Hugh Dickins Signed-off-by: Catalin Marinas Cc: Russell King Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman