From 413b43deab8377819aba1dbad2abf0c15d59b491 Mon Sep 17 00:00:00 2001 From: Ravikiran G Thirumalai Date: Tue, 23 Mar 2010 13:35:28 -0700 Subject: tmpfs: fix oops on mounts with mpol=default Fix an 'oops' when a tmpfs mount point is mounted with the mpol=default mempolicy. Upon remounting a tmpfs mount point with 'mpol=default' option, the mount code crashed with a null pointer dereference. The initial problem report was on 2.6.27, but the problem exists in mainline 2.6.34-rc as well. On examining the code, we see that mpol_new returns NULL if default mempolicy was requested. This 'NULL' mempolicy is accessed to store the node mask resulting in oops. The following patch fixes it. Signed-off-by: Ravikiran Thirumalai Signed-off-by: KOSAKI Motohiro Cc: Christoph Lameter Cc: Mel Gorman Acked-by: Lee Schermerhorn Cc: Hugh Dickins Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mempolicy.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'mm/mempolicy.c') diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 643f66e10187..745ce90308a6 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2215,10 +2215,15 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) goto out; mode = MPOL_PREFERRED; break; - + case MPOL_DEFAULT: + /* + * Insist on a empty nodelist + */ + if (!nodelist) + err = 0; + goto out; /* * case MPOL_BIND: mpol_new() enforces non-empty nodemask. - * case MPOL_DEFAULT: mpol_new() enforces empty nodemask, ignores flags. */ } -- cgit v1.2.2 From d69b2e63e9172afb4d07c305601b79a55509ac4c Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Tue, 23 Mar 2010 13:35:30 -0700 Subject: tmpfs: mpol=bind:0 don't cause mount error. Currently, following mount operation cause mount error. % mount -t tmpfs -ompol=bind:0 none /tmp Because commit 71fe804b6d5 (mempolicy: use struct mempolicy pointer in shmem_sb_info) corrupted MPOL_BIND parse code. This patch restore the needed one. Signed-off-by: KOSAKI Motohiro Cc: Ravikiran Thirumalai Cc: Christoph Lameter Cc: Mel Gorman Acked-by: Lee Schermerhorn Cc: Hugh Dickins Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mempolicy.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'mm/mempolicy.c') diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 745ce90308a6..10db44f95749 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2222,9 +2222,13 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) if (!nodelist) err = 0; goto out; - /* - * case MPOL_BIND: mpol_new() enforces non-empty nodemask. - */ + case MPOL_BIND: + /* + * Insist on a nodelist + */ + if (!nodelist) + goto out; + err = 0; } mode_flags = 0; -- cgit v1.2.2 From 12821f5fb942e795f8009ece14bde868893bd811 Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Tue, 23 Mar 2010 13:35:31 -0700 Subject: tmpfs: handle MPOL_LOCAL mount option properly commit 71fe804b6d5 (mempolicy: use struct mempolicy pointer in shmem_sb_info) added mpol=local mount option. but its feature is broken since it was born. because such code always return 1 (i.e. mount failure). This patch fixes it. Signed-off-by: KOSAKI Motohiro Cc: Ravikiran Thirumalai Cc: Christoph Lameter Cc: Mel Gorman Acked-by: Lee Schermerhorn Cc: Hugh Dickins Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mempolicy.c | 1 + 1 file changed, 1 insertion(+) (limited to 'mm/mempolicy.c') diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 10db44f95749..fb71790398f0 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2214,6 +2214,7 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) if (nodelist) goto out; mode = MPOL_PREFERRED; + err = 0; break; case MPOL_DEFAULT: /* -- cgit v1.2.2 From 926f2ae04f183098cf9a30521776fb2759c8afeb Mon Sep 17 00:00:00 2001 From: KOSAKI Motohiro Date: Tue, 23 Mar 2010 13:35:32 -0700 Subject: tmpfs: cleanup mpol_parse_str() mpol_parse_str() made lots 'err' variable related bug. Because it is ugly and reviewing unfriendly. This patch simplifies it. Signed-off-by: KOSAKI Motohiro Cc: Ravikiran Thirumalai Cc: Christoph Lameter Cc: Mel Gorman Acked-by: Lee Schermerhorn Cc: Hugh Dickins Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mempolicy.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) (limited to 'mm/mempolicy.c') diff --git a/mm/mempolicy.c b/mm/mempolicy.c index fb71790398f0..6cdfa1df57f6 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2195,8 +2195,8 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) char *rest = nodelist; while (isdigit(*rest)) rest++; - if (!*rest) - err = 0; + if (*rest) + goto out; } break; case MPOL_INTERLEAVE: @@ -2205,7 +2205,6 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) */ if (!nodelist) nodes = node_states[N_HIGH_MEMORY]; - err = 0; break; case MPOL_LOCAL: /* @@ -2214,7 +2213,6 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) if (nodelist) goto out; mode = MPOL_PREFERRED; - err = 0; break; case MPOL_DEFAULT: /* @@ -2229,7 +2227,6 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) */ if (!nodelist) goto out; - err = 0; } mode_flags = 0; @@ -2243,13 +2240,14 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) else if (!strcmp(flags, "relative")) mode_flags |= MPOL_F_RELATIVE_NODES; else - err = 1; + goto out; } new = mpol_new(mode, mode_flags, &nodes); if (IS_ERR(new)) - err = 1; - else { + goto out; + + { int ret; NODEMASK_SCRATCH(scratch); if (scratch) { @@ -2260,13 +2258,15 @@ int mpol_parse_str(char *str, struct mempolicy **mpol, int no_context) ret = -ENOMEM; NODEMASK_SCRATCH_FREE(scratch); if (ret) { - err = 1; mpol_put(new); - } else if (no_context) { - /* save for contextualization */ - new->w.user_nodemask = nodes; + goto out; } } + err = 0; + if (no_context) { + /* save for contextualization */ + new->w.user_nodemask = nodes; + } out: /* Restore string for error message */ -- cgit v1.2.2 From c6b6ef8bb05af632889c5536513b9f4004961f73 Mon Sep 17 00:00:00 2001 From: Lee Schermerhorn Date: Tue, 23 Mar 2010 13:35:41 -0700 Subject: mempolicy: fix get_mempolicy() for relative and static nodes Discovered while testing other mempolicy changes: get_mempolicy() does not handle static/relative mode flags correctly. Return the value that the user specified so that it can be restored via set_mempolicy() if desired. Signed-off-by: Lee Schermerhorn Cc: Hugh Dickins Cc: Ravikiran Thirumalai Cc: KOSAKI Motohiro Cc: Christoph Lameter Cc: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mempolicy.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'mm/mempolicy.c') diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 6cdfa1df57f6..8034abd3a135 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -806,9 +806,13 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask, err = 0; if (nmask) { - task_lock(current); - get_policy_nodemask(pol, nmask); - task_unlock(current); + if (mpol_store_user_nodemask(pol)) { + *nmask = pol->w.user_nodemask; + } else { + task_lock(current); + get_policy_nodemask(pol, nmask); + task_unlock(current); + } } out: -- cgit v1.2.2 From 5a0e3ad6af8660be21ca98a971cd00f331318c05 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 24 Mar 2010 17:04:11 +0900 Subject: include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn --- mm/mempolicy.c | 1 - 1 file changed, 1 deletion(-) (limited to 'mm/mempolicy.c') diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 8034abd3a135..08f40a2f3fe0 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -73,7 +73,6 @@ #include #include #include -#include #include #include #include -- cgit v1.2.2