- 14 10月, 2014 26 次提交
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由 Peter Feiner 提交于
For VMAs that don't want write notifications, PTEs created for read faults have their write bit set. If the read fault happens after VM_SOFTDIRTY is cleared, then the PTE's softdirty bit will remain clear after subsequent writes. Here's a simple code snippet to demonstrate the bug: char* m = mmap(NULL, getpagesize(), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); system("echo 4 > /proc/$PPID/clear_refs"); /* clear VM_SOFTDIRTY */ assert(*m == '\0'); /* new PTE allows write access */ assert(!soft_dirty(x)); *m = 'x'; /* should dirty the page */ assert(soft_dirty(x)); /* fails */ With this patch, write notifications are enabled when VM_SOFTDIRTY is cleared. Furthermore, to avoid unnecessary faults, write notifications are disabled when VM_SOFTDIRTY is set. As a side effect of enabling and disabling write notifications with care, this patch fixes a bug in mprotect where vm_page_prot bits set by drivers were zapped on mprotect. An analogous bug was fixed in mmap by commit c9d0bf24 ("mm: uncached vma support with writenotify"). Signed-off-by: NPeter Feiner <pfeiner@google.com> Reported-by: NPeter Feiner <pfeiner@google.com> Suggested-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Jamie Liu <jamieliu@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Zach Brown 提交于
It's very common for the buffer heads in the lru to have different block numbers. By comparing the blocknr before the bdev and size we can reduce the cost of searching in the very common case where all the entries have the same bdev and size. In quick hot cache cycle counting tests on a single fs workstation this cut the cost of a miss by about 20%. A diff of the disassembly shows the reordering of the bdev and blocknr comparisons. This is in such a tiny loop that skipping one comparison is a meaningful portion of the total work being done: 1628: 83 c1 01 add $0x1,%ecx 162b: 83 f9 08 cmp $0x8,%ecx 162e: 74 60 je 1690 <__find_get_block+0xa0> 1630: 89 c8 mov %ecx,%eax 1632: 65 4c 8b 04 c5 00 00 mov %gs:0x0(,%rax,8),%r8 1639: 00 00 163b: 4d 85 c0 test %r8,%r8 163e: 4c 89 c3 mov %r8,%rbx 1641: 74 e5 je 1628 <__find_get_block+0x38> - 1643: 4d 3b 68 30 cmp 0x30(%r8),%r13 + 1643: 4d 3b 68 18 cmp 0x18(%r8),%r13 1647: 75 df jne 1628 <__find_get_block+0x38> - 1649: 4d 3b 60 18 cmp 0x18(%r8),%r12 + 1649: 4d 3b 60 30 cmp 0x30(%r8),%r12 164d: 75 d9 jne 1628 <__find_get_block+0x38> 164f: 49 39 50 20 cmp %rdx,0x20(%r8) 1653: 75 d3 jne 1628 <__find_get_block+0x38> Signed-off-by: NZach Brown <zab@zabbo.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
The kernel used to contain two functions for length-delimited, case-insensitive string comparison, strnicmp with correct semantics and a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp was renamed to strncasecmp, and strnicmp made into a wrapper for the new strncasecmp to avoid breaking existing users. To allow the compat wrapper strnicmp to be removed at some point in the future, and to avoid the extra indirection cost, do s/strnicmp/strncasecmp/g. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: NJan Kara <jack@suse.cz> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
The kernel used to contain two functions for length-delimited, case-insensitive string comparison, strnicmp with correct semantics and a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp was renamed to strncasecmp, and strnicmp made into a wrapper for the new strncasecmp to avoid breaking existing users. To allow the compat wrapper strnicmp to be removed at some point in the future, and to avoid the extra indirection cost, do s/strnicmp/strncasecmp/g. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Rasmus Villemoes 提交于
The kernel used to contain two functions for length-delimited, case-insensitive string comparison, strnicmp with correct semantics and a slightly buggy strncasecmp. The latter is the POSIX name, so strnicmp was renamed to strncasecmp, and strnicmp made into a wrapper for the new strncasecmp to avoid breaking existing users. To allow the compat wrapper strnicmp to be removed at some point in the future, and to avoid the extra indirection cost, do s/strnicmp/strncasecmp/g. Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Steve French <sfrench@samba.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Fabian Frederick 提交于
This patch defines maximum block number to 2^31. It also converts bitmap_size and array_size to unsigned int in omfs_get_imap Signed-off-by: NFabian Frederick <fabf@skynet.be> Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org> Suggested-by: NBob Copeland <me@bobcopeland.com> Acked-by: NBob Copeland <me@bobcopeland.com> Tested-by: NBob Copeland <me@bobcopeland.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Fabian Frederick 提交于
sys_tz is already declared in include/linux/time.h Signed-off-by: NFabian Frederick <fabf@skynet.be> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Fabian Frederick 提交于
Four functions declared variables twice resulting in shadow warnings. This patch renames internal variables and adds blank line after declarations. Signed-off-by: NFabian Frederick <fabf@skynet.be> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Fabian Frederick 提交于
head is set to AFFS_HEAD(bh) but never used. Signed-off-by: NFabian Frederick <fabf@skynet.be> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Fabian Frederick 提交于
key is set in affs_fill_super but never used. Signed-off-by: NFabian Frederick <fabf@skynet.be> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Oleg Nesterov 提交于
format_corename() can only pass the leader's pid to the core handler, but there is no simple way to figure out which thread originated the coredump. As Jan explains, this also means that there is no simple way to create the backtrace of the crashed process: As programs are mostly compiled with implicit gcc -fomit-frame-pointer one needs program's .eh_frame section (equivalently PT_GNU_EH_FRAME segment) or .debug_frame section. .debug_frame usually is present only in separate debug info files usually not even installed on the system. While .eh_frame is a part of the executable/library (and it is even always mapped for C++ exceptions unwinding) it no longer has to be present anywhere on the disk as the program could be upgraded in the meantime and the running instance has its executable file already unlinked from disk. One possibility is to echo 0x3f >/proc/*/coredump_filter and dump all the file-backed memory including the executable's .eh_frame section. But that can create huge core files, for example even due to mmapped data files. Other possibility would be to read .eh_frame from /proc/PID/mem at the core_pattern handler time of the core dump. For the backtrace one needs to read the register state first which can be done from core_pattern handler: ptrace(PTRACE_SEIZE, tid, 0, PTRACE_O_TRACEEXIT) close(0); // close pipe fd to resume the sleeping dumper waitpid(); // should report EXIT PTRACE_GETREGS or other requests The remaining problem is how to get the 'tid' value of the crashed thread. It could be read from the first NT_PRSTATUS note of the core file but that makes the core_pattern handler complicated. Unfortunately %t is already used so this patch uses %i/%I. Automatic Bug Reporting Tool (https://github.com/abrt/abrt/wiki/overview) is experimenting with this. It is using the elfutils (https://fedorahosted.org/elfutils/) unwinder for generating the backtraces. Apart from not needing matching executables as mentioned above, another advantage is that we can get the backtrace without saving the core (which might be quite large) to disk. [mmilata@redhat.com: final paragraph of changelog] Signed-off-by: NJan Kratochvil <jan.kratochvil@redhat.com> Signed-off-by: NOleg Nesterov <oleg@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Cc: Mark Wielaard <mjw@redhat.com> Cc: Martin Milata <mmilata@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Fabian Frederick 提交于
sys_tz is already declared extern struct in include/linux/time.h Signed-off-by: NFabian Frederick <fabf@skynet.be> Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Fabian Frederick 提交于
Merge conditional unlock/lock in the same condition to avoid sparse warning: fs/reiserfs/journal.c:703:36: warning: context imbalance in 'add_to_chunk' - unexpected unlock Signed-off-by: NFabian Frederick <fabf@skynet.be> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Fabian Frederick 提交于
ucg is defined and set in ufs_bitmap_search but never used. Signed-off-by: NFabian Frederick <fabf@skynet.be> Cc: Evgeniy Dushistov <dushistov@mail.ru> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Fabian Frederick 提交于
sys_tz is already declared in include/linux/time.h Signed-off-by: NFabian Frederick <fabf@skynet.be> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andreas Rohner 提交于
Support for fdatasync() has been implemented in NILFS2 for a long time, but whenever the corresponding inode is dirty the implementation falls back to a full-flegded sync(). Since every write operation has to update the modification time of the file, the inode will almost always be dirty and fdatasync() will fall back to sync() most of the time. But this fallback is only necessary for a change of the file size and not for a change of the various timestamps. This patch adds a new flag NILFS_I_INODE_SYNC to differentiate between those two situations. * If it is set the file size was changed and a full sync is necessary. * If it is not set then only the timestamps were updated and fdatasync() can go ahead. There is already a similar flag I_DIRTY_DATASYNC on the VFS layer with the exact same semantics. Unfortunately it cannot be used directly, because NILFS2 doesn't implement write_inode() and doesn't clear the VFS flags when inodes are written out. So the VFS writeback thread can clear I_DIRTY_DATASYNC at any time without notifying NILFS2. So I_DIRTY_DATASYNC has to be mapped onto NILFS_I_INODE_SYNC in nilfs_update_inode(). Signed-off-by: NAndreas Rohner <andreas.rohner@gmx.net> Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andreas Rohner 提交于
Under normal circumstances nilfs_sync_fs() writes out the super block, which causes a flush of the underlying block device. But this depends on the THE_NILFS_SB_DIRTY flag, which is only set if the pointer to the last segment crosses a segment boundary. So if only a small amount of data is written before the call to nilfs_sync_fs(), no flush of the block device occurs. In the above case an additional call to blkdev_issue_flush() is needed. To prevent unnecessary overhead, the new flag nilfs->ns_flushed_device is introduced, which is cleared whenever new logs are written and set whenever the block device is flushed. For convenience the function nilfs_flush_device() is added, which contains the above logic. Signed-off-by: NAndreas Rohner <andreas.rohner@gmx.net> Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Himangi Saraogi 提交于
The Linux kernel coding style guidelines suggest not using typedefs for structure types. This patch gets rid of the typedef for befs_btree_node. The following Coccinelle semantic patch detects the case. @tn1@ type td; @@ typedef struct { ... } td; @script:python tf@ td << tn1.td; tdres; @@ coccinelle.tdres = td; @@ type tn1.td; identifier tf.tdres; @@ -typedef struct + tdres { ... } -td ; @@ type tn1.td; identifier tf.tdres; @@ -td + struct tdres Signed-off-by: NHimangi Saraogi <himangi774@gmail.com> Acked-by: NJulia Lawall <julia.lawall@lip6.fr> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 NeilBrown 提交于
If rcu-walk mode we don't *have* to return -EISDIR for non-mount-traps as we will simply drop into REF-walk and handling DCACHE_NEED_AUTOMOUNT dentrys the slow way. But it is better if we do when possible. In 'oz_mode', use the same condition as ref-walk: if not a mountpoint, then it must be -EISDIR. In regular mode there are most tests needed. Most of them can be performed without taking any spinlocks. If we find a directory that isn't obviously empty, and isn't mounted on, we need to call 'simple_empty()' which does take a spinlock. If this turned out to hurt performance, some other approach could be found to signal when a directory is known to be empty. Signed-off-by: NNeilBrown <neilb@suse.de> Reviewed-by: NIan Kent <raven@themaw.net> Tested-by: NIan Kent <raven@themaw.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 NeilBrown 提交于
->fs_lock protects AUTOFS_INF_EXPIRING. We need to be sure that once the flag is set, no new references beneath the dentry are taken. So rcu-walk currently needs to take fs_lock before checking the flag. This hurts performance. Change the expiry to a two-stage process. First set AUTOFS_INF_NO_RCU which forces any path walk into ref-walk mode, then drop the lock and call synchronize_rcu(). Once that returns we can be sure no rcu-walk is active beneath the dentry and we can check reference counts again. Now during an RCU-walk we can test AUTOFS_INF_EXPIRING without taking the lock as along as we test AUTOFS_INF_NO_RCU too. If either are set, we must abort the RCU-walk If neither are set, we know that refcounts will be tested again after we finish the RCU-walk so we are safe to continue. ->fs_lock is still taken in d_manage() to check for a non-trap directory. That will be resolved in the next patch. Signed-off-by: NNeilBrown <neilb@suse.de> Reviewed-by: NIan Kent <raven@themaw.net> Tested-by: NIan Kent <raven@themaw.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 NeilBrown 提交于
Have a "test" function change the value it is testing can be confusing, particularly as a future patch will be calling this function twice. So move the update for 'last_used' to avoid repeat expiry to the place where the final determination on what to expire is known. Signed-off-by: NNeilBrown <neilb@suse.de> Reviewed-by: NIan Kent <raven@themaw.net> Tested-by: NIan Kent <raven@themaw.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 NeilBrown 提交于
Future patch will potentially call this twice, so make it separate. Signed-off-by: NNeilBrown <neilb@suse.de> Reviewed-by: NIan Kent <raven@themaw.net> Tested-by: NIan Kent <raven@themaw.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 NeilBrown 提交于
This series teaches autofs about RCU-walk so that we don't drop straight into REF-walk when we hit an autofs directory, and so that we avoid spinlocks as much as possible when performing an RCU-walk. This is needed so that the benefits of the recent NFS support for RCU-walk are fully available when NFS filesystems are automounted. Patches have been carefully reviewed and tested both with test suites and in production - thanks a lot to Ian Kent for his support there. This patch (of 6): Any attempt to look up a pathname that passes though an autofs4 mount is currently forced out of RCU-walk into REF-walk. This can significantly hurt performance of many-thread work loads on many-core systems, especially if the automounted filesystem supports RCU-walk but doesn't get to benefit from it. So if autofs4_d_manage is called with rcu_walk set, only fail with -ECHILD if it is necessary to wait longer than a spinlock. Signed-off-by: NNeilBrown <neilb@suse.de> Reviewed-by: NIan Kent <raven@themaw.net> Tested-by: NIan Kent <raven@themaw.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Fabian Frederick 提交于
sys_tz is already declared in include/linux/time.h Signed-off-by: NFabian Frederick <fabf@skynet.be> Cc: Petr Vandrovec <petr@vandrovec.name> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Arnd Bergmann 提交于
gcc-4.9 on ARM gives us a mysterious warning about the binfmt_misc parse_command function: fs/binfmt_misc.c: In function 'parse_command.part.3': fs/binfmt_misc.c:405:7: warning: array subscript is above array bounds [-Warray-bounds] I've managed to trace this back to the ARM implementation of memset, which is called from copy_from_user in case of a fault and which does #define memset(p,v,n) \ ({ \ void *__p = (p); size_t __n = n; \ if ((__n) != 0) { \ if (__builtin_constant_p((v)) && (v) == 0) \ __memzero((__p),(__n)); \ else \ memset((__p),(v),(__n)); \ } \ (__p); \ }) Apparently gcc gets confused by the check for "size != 0" and believes that the size might be zero when it gets to the line that does "if (s[count-1] == '\n')", so it would access data outside of the array. gcc is clearly wrong here, since this condition was already checked earlier in the function and the 'size' value can not change in the meantime. Fortunately, we can work around it and get rid of the warning by rearranging the function to check for zero size after doing the copy_from_user. It is still safe to pass a zero size into copy_from_user, so it does not cause any side effects. Signed-off-by: NArnd Bergmann <arnd@arndb.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mike Frysinger 提交于
The current code places a 256 byte limit on the registration format. This ends up being fairly limited when you try to do matching against a binary format like ELF: - the magic & mask formats cannot have any embedded NUL chars (string_unescape_inplace halts at the first NUL) - each escape sequence quadruples the size: \x00 is needed for NUL - trying to match bytes at the start of the file as well as further on leads to a lot of \x00 sequences in the mask - magic & mask have to be the same length (when decoded) - still need bytes for the other fields - impossible! Let's look at a concrete (and common) example: using QEMU to run MIPS ELFs. The name field uses 11 bytes "qemu-mipsel". The interp uses 20 bytes "/usr/bin/qemu-mipsel". The type & flags takes up 4 bytes. We need 7 bytes for the delimiter (usually ":"). We can skip offset. So already we're down to 107 bytes to use with the magic/mask instead of the real limit of 128 (BINPRM_BUF_SIZE). If people use shell code to register (which they do the majority of the time), they're down to ~26 possible bytes since the escape sequence must be \x##. The ELF format looks like (both 32 & 64 bit): e_ident: 16 bytes e_type: 2 bytes e_machine: 2 bytes Those 20 bytes are enough for most architectures because they have so few formats in the first place, thus they can be uniquely identified. That also means for shell users, since 20 is smaller than 26, they can sanely register a handler. But for some targets (like MIPS), we need to poke further. The ELF fields continue on: e_entry: 4 or 8 bytes e_phoff: 4 or 8 bytes e_shoff: 4 or 8 bytes e_flags: 4 bytes We only care about e_flags here as that includes the bits to identify whether the ELF is O32/N32/N64. But now we have to consume another 16 bytes (for 32 bit ELFs) or 28 bytes (for 64 bit ELFs) just to match the flags. If every byte is escaped, we send 288 more bytes to the kernel ((20 {e_ident,e_type,e_machine} + 12 {e_entry,e_phoff,e_shoff} + 4 {e_flags}) * 2 {mask,magic} * 4 {escape}) and we've clearly blown our budget. Even if we try to be clever and do the decoding ourselves (rather than relying on the kernel to process \x##), we still can't hit the mark -- string_unescape_inplace treats mask & magic as C strings so NUL cannot be embedded. That leaves us with having to pass \x00 for the 12/24 entry/phoff/shoff bytes (as those will be completely random addresses), and that is a minimum requirement of 48/96 bytes for the mask alone. Add up the rest and we blow through it (this is for 64 bit ELFs): magic: 20 {e_ident,e_type,e_machine} + 24 {e_entry,e_phoff,e_shoff} + 4 {e_flags} = 48 # ^^ See note below. mask: 20 {e_ident,e_type,e_machine} + 96 {e_entry,e_phoff,e_shoff} + 4 {e_flags} = 120 Remember above we had 107 left over, and now we're at 168. This is of course the *best* case scenario -- you'll also want to have NUL bytes in the magic & mask too to match literal zeros. Note: the reason we can use 24 in the magic is that we can work off of the fact that for bytes the mask would clobber, we can stuff any value into magic that we want. So when mask is \x00, we don't need the magic to also be \x00, it can be an unescaped raw byte like '!'. This lets us handle more formats (barely) under the current 256 limit, but that's a pretty tall hoop to force people to jump through. With all that said, let's bump the limit from 256 bytes to 1920. This way we support escaping every byte of the mask & magic field (which is 1024 bytes by themselves -- 128 * 4 * 2), and we leave plenty of room for other fields. Like long paths to the interpreter (when you have source in your /really/long/homedir/qemu/foo). Since the current code stuffs more than one structure into the same buffer, we leave a bit of space to easily round up to 2k. 1920 is just as arbitrary as 256 ;). Signed-off-by: NMike Frysinger <vapier@gentoo.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 13 10月, 2014 6 次提交
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由 Eric Sandeen 提交于
caused a regression in xfs_inumbers, which in turn broke xfsdump, causing incomplete dumps. The loop in xfs_inumbers() needs to fill the user-supplied buffers, and iterates via xfs_btree_increment, reading new ags as needed. But the first time through the loop, if xfs_btree_increment() succeeds, we continue, which triggers the ++agno at the bottom of the loop, and we skip to soon to the next ag - without the proper setup under next_ag to read the next ag. Fix this by removing the agno increment from the loop conditional, and only increment agno if we have actually hit the code under the next_ag: target. Cc: stable@vger.kernel.org Signed-off-by: NEric Sandeen <sandeen@redhat.com> Reviewed-by: NDave Chinner <dchinner@redhat.com> Signed-off-by: NDave Chinner <david@fromorbit.com>
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由 Eric Biggers 提交于
This comment is 5 years outdated; init_file() no longer exists. Signed-off-by: NEric Biggers <ebiggers3@gmail.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Eric Biggers 提交于
The following pairs of system calls dealing with extended attributes only differ in their behavior on whether the symbolic link is followed (when the named file is a symbolic link): - setxattr() and lsetxattr() - getxattr() and lgetxattr() - listxattr() and llistxattr() - removexattr() and lremovexattr() Despite this, the implementations all had duplicated code, so this commit redirects each of the above pairs of system calls to a corresponding function to which different lookup flags (LOOKUP_FOLLOW or 0) are passed. For me this reduced the stripped size of xattr.o from 8824 to 8248 bytes. Signed-off-by: NEric Biggers <ebiggers3@gmail.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
never used outside and it's too low-level for legitimate uses outside of fs/dcache.c anyway Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
As it is, path_lookupat() and path_mounpoint() might end up leaking struct file reference in some cases. Spotted-by: NEric Biggers <ebiggers3@gmail.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 10 10月, 2014 8 次提交
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由 Sebastien Buisson 提交于
Increase the buffer-head per-CPU LRU size to allow efficient filesystem operations that access many blocks for each transaction. For example, creating a file in a large ext4 directory with quota enabled will access multiple buffer heads and will overflow the LRU at the default 8-block LRU size: * parent directory inode table block (ctime, nlinks for subdirs) * new inode bitmap * inode table block * 2 quota blocks * directory leaf block (not reused, but pollutes one cache entry) * 2 levels htree blocks (only one is reused, other pollutes cache) * 2 levels indirect/index blocks (only one is reused) The buffer-head per-CPU LRU size is raised to 16, as it shows in metadata performance benchmarks up to 10% gain for create, 4% for lookup and 7% for destroy. Signed-off-by: NLiang Zhen <liang.zhen@intel.com> Signed-off-by: NAndreas Dilger <andreas.dilger@intel.com> Signed-off-by: NSebastien Buisson <sebastien.buisson@bull.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Konstantin Khlebnikov 提交于
Always mark pages with PageBalloon even if balloon compaction is disabled and expose this mark in /proc/kpageflags as KPF_BALLOON. Also this patch adds three counters into /proc/vmstat: "balloon_inflate", "balloon_deflate" and "balloon_migrate". They accumulate balloon activity. Current size of balloon is (balloon_inflate - balloon_deflate) pages. All generic balloon code now gathered under option CONFIG_MEMORY_BALLOON. It should be selected by ballooning driver which wants use this feature. Currently virtio-balloon is the only user. Signed-off-by: NKonstantin Khlebnikov <k.khlebnikov@samsung.com> Cc: Rafael Aquini <aquini@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Peter Feiner 提交于
If a /proc/pid/pagemap read spans a [VMA, an unmapped region, then a VM_SOFTDIRTY VMA], the virtual pages in the unmapped region are reported as softdirty. Here's a program to demonstrate the bug: int main() { const uint64_t PAGEMAP_SOFTDIRTY = 1ul << 55; uint64_t pme[3]; int fd = open("/proc/self/pagemap", O_RDONLY);; char *m = mmap(NULL, 3 * getpagesize(), PROT_READ, MAP_ANONYMOUS | MAP_SHARED, -1, 0); munmap(m + getpagesize(), getpagesize()); pread(fd, pme, 24, (unsigned long) m / getpagesize() * 8); assert(pme[0] & PAGEMAP_SOFTDIRTY); /* passes */ assert(!(pme[1] & PAGEMAP_SOFTDIRTY)); /* fails */ assert(pme[2] & PAGEMAP_SOFTDIRTY); /* passes */ return 0; } (Note that all pages in new VMAs are softdirty until cleared). Tested: Used the program given above. I'm going to include this code in a selftest in the future. [n-horiguchi@ah.jp.nec.com: prevent pagemap_pte_range() from overrunning] Signed-off-by: NPeter Feiner <pfeiner@google.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Jamie Liu <jamieliu@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Xue jiufei 提交于
Fix a deadlock problem caused by direct memory reclaim in o2net_wq. The situation is as follows: 1) Receive a connect message from another node, node queues a work_struct o2net_listen_work. 2) o2net_wq processes this work and call the following functions: o2net_wq -> o2net_accept_one -> sock_create_lite -> sock_alloc() -> kmem_cache_alloc with GFP_KERNEL -> ____cache_alloc_node ->__alloc_pages_nodemask -> do_try_to_free_pages -> shrink_slab -> evict -> ocfs2_evict_inode -> ocfs2_drop_lock -> dlmunlock -> o2net_send_message_vec then o2net_wq wait for the unlock reply from master. 3) tcp layer received the reply, call o2net_data_ready() and queue sc_rx_work, waiting o2net_wq to process this work. 4) o2net_wq is a single thread workqueue, it process the work one by one. Right now it is still doing o2net_listen_work and cannot handle sc_rx_work. so we deadlock. Junxiao Bi's patch "mm: clear __GFP_FS when PF_MEMALLOC_NOIO is set" (http://ozlabs.org/~akpm/mmots/broken-out/mm-clear-__gfp_fs-when-pf_memalloc_noio-is-set.patch) clears __GFP_FS in memalloc_noio_flags() besides __GFP_IO. We use memalloc_noio_save() to set process flag PF_MEMALLOC_NOIO so that all allocations done by this process are done as if GFP_NOIO was specified. We are not reentering filesystem while doing memory reclaim. Signed-off-by: Njoyce.xue <xuejiufei@huawei.com> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Oleg Nesterov 提交于
9e781440 "hold task->mempolicy while numa_maps scans." fixed the race with the exiting task but this is not enough. The current code assumes that get_vma_policy(task) should either see task->mempolicy == NULL or it should be equal to ->task_mempolicy saved by hold_task_mempolicy(), so we can never race with __mpol_put(). But this can only work if we can't race with do_set_mempolicy(), and thus we can't race with another do_set_mempolicy() or do_exit() after that. However, do_set_mempolicy()->down_write(mmap_sem) can not prevent this race. This task can exec, change it's ->mm, and call do_set_mempolicy() after that; in this case they take 2 different locks. Change hold_task_mempolicy() to use get_task_policy(), it never returns NULL, and change show_numa_map() to use __get_vma_policy() or fall back to proc_priv->task_mempolicy. Note: this is the minimal fix, we will cleanup this code later. I think hold_task_mempolicy() and release_task_mempolicy() should die, we can move this logic into show_numa_map(). Or we can move get_task_policy() outside of ->mmap_sem and !CONFIG_NUMA code at least. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Hugh Dickins <hughd@google.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Akinobu Mita 提交于
Sequential read from a block device is expected to be equal or faster than from the file on a filesystem. But it is not correct due to the lack of effective readpages() in the address space operations for block device. This implements readpages() operation for block device by using mpage_readpages() which can create multipage BIOs instead of BIOs for each page and reduce system CPU time consumption. Install 1GB of RAM disk storage: # modprobe scsi_debug dev_size_mb=1024 delay=0 Sequential read from file on a filesystem: # mkfs.ext4 /dev/$DEV # mount /dev/$DEV /mnt # fio --name=t --size=512m --rw=read --filename=/mnt/file ... read : io=524288KB, bw=2133.4MB/s, iops=546133, runt= 240msec Sequential read from a block device: # fio --name=t --size=512m --rw=read --filename=/dev/$DEV ... (Without this commit) read : io=524288KB, bw=1700.2MB/s, iops=435455, runt= 301msec (With this commit) read : io=524288KB, bw=2160.4MB/s, iops=553046, runt= 237msec Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Akinobu Mita 提交于
Add guard_bio_eod() check for mpage code in order to allow us to do IO even on the odd last sectors of a device, even if the block size is some multiple of the physical sector size. Using mpage_readpages() for block device requires this guard check. Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Akinobu Mita 提交于
This patchset implements readpages() operation for block device by using mpage_readpages() which can create multipage BIOs instead of BIOs for each page and reduce system CPU time consumption. This patch (of 3): guard_bh_eod() is used in submit_bh() to allow us to do IO even on the odd last sectors of a device, even if the block size is some multiple of the physical sector size. This makes guard_bh_eod() more generic and renames it guard_bio_eod() so that we can use it without struct buffer_head argument. The reason for this change is that using mpage_readpages() for block device requires to add this guard check in mpage code. Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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