diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/Kconfig | 1 | ||||
| -rw-r--r-- | fs/dax.c | 2 | ||||
| -rw-r--r-- | fs/ext2/Kconfig | 1 | ||||
| -rw-r--r-- | fs/ext4/Kconfig | 1 | ||||
| -rw-r--r-- | fs/proc/base.c | 2 | ||||
| -rw-r--r-- | fs/romfs/super.c | 23 | ||||
| -rw-r--r-- | fs/userfaultfd.c | 37 |
7 files changed, 60 insertions, 7 deletions
diff --git a/fs/Kconfig b/fs/Kconfig index c2a377cdda2b..83eab52fb3f6 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -38,6 +38,7 @@ config FS_DAX bool "Direct Access (DAX) support" depends on MMU depends on !(ARM || MIPS || SPARC) + select FS_IOMAP help Direct Access (DAX) can be used on memory-backed block devices. If the block device supports DAX and the filesystem supports DAX, @@ -990,7 +990,6 @@ int __dax_zero_page_range(struct block_device *bdev, sector_t sector, } EXPORT_SYMBOL_GPL(__dax_zero_page_range); -#ifdef CONFIG_FS_IOMAP static sector_t dax_iomap_sector(struct iomap *iomap, loff_t pos) { return iomap->blkno + (((pos & PAGE_MASK) - iomap->offset) >> 9); @@ -1428,4 +1427,3 @@ int dax_iomap_pmd_fault(struct vm_area_struct *vma, unsigned long address, } EXPORT_SYMBOL_GPL(dax_iomap_pmd_fault); #endif /* CONFIG_FS_DAX_PMD */ -#endif /* CONFIG_FS_IOMAP */ diff --git a/fs/ext2/Kconfig b/fs/ext2/Kconfig index 36bea5adcaba..c634874e12d9 100644 --- a/fs/ext2/Kconfig +++ b/fs/ext2/Kconfig @@ -1,6 +1,5 @@ config EXT2_FS tristate "Second extended fs support" - select FS_IOMAP if FS_DAX help Ext2 is a standard Linux file system for hard disks. diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig index 7b90691e98c4..e38039fd96ff 100644 --- a/fs/ext4/Kconfig +++ b/fs/ext4/Kconfig @@ -37,7 +37,6 @@ config EXT4_FS select CRC16 select CRYPTO select CRYPTO_CRC32C - select FS_IOMAP if FS_DAX help This is the next generation of the ext3 filesystem. diff --git a/fs/proc/base.c b/fs/proc/base.c index 8e7e61b28f31..87c9a9aacda3 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -3179,6 +3179,8 @@ int proc_pid_readdir(struct file *file, struct dir_context *ctx) iter.tgid += 1, iter = next_tgid(ns, iter)) { char name[PROC_NUMBUF]; int len; + + cond_resched(); if (!has_pid_permissions(ns, iter.task, 2)) continue; diff --git a/fs/romfs/super.c b/fs/romfs/super.c index d0f8a38dfafa..0186fe6d39f3 100644 --- a/fs/romfs/super.c +++ b/fs/romfs/super.c @@ -74,6 +74,7 @@ #include <linux/highmem.h> #include <linux/pagemap.h> #include <linux/uaccess.h> +#include <linux/major.h> #include "internal.h" static struct kmem_cache *romfs_inode_cachep; @@ -416,7 +417,22 @@ static void romfs_destroy_inode(struct inode *inode) static int romfs_statfs(struct dentry *dentry, struct kstatfs *buf) { struct super_block *sb = dentry->d_sb; - u64 id = huge_encode_dev(sb->s_bdev->bd_dev); + u64 id = 0; + + /* When calling huge_encode_dev(), + * use sb->s_bdev->bd_dev when, + * - CONFIG_ROMFS_ON_BLOCK defined + * use sb->s_dev when, + * - CONFIG_ROMFS_ON_BLOCK undefined and + * - CONFIG_ROMFS_ON_MTD defined + * leave id as 0 when, + * - CONFIG_ROMFS_ON_BLOCK undefined and + * - CONFIG_ROMFS_ON_MTD undefined + */ + if (sb->s_bdev) + id = huge_encode_dev(sb->s_bdev->bd_dev); + else if (sb->s_dev) + id = huge_encode_dev(sb->s_dev); buf->f_type = ROMFS_MAGIC; buf->f_namelen = ROMFS_MAXFN; @@ -489,6 +505,11 @@ static int romfs_fill_super(struct super_block *sb, void *data, int silent) sb->s_flags |= MS_RDONLY | MS_NOATIME; sb->s_op = &romfs_super_ops; +#ifdef CONFIG_ROMFS_ON_MTD + /* Use same dev ID from the underlying mtdblock device */ + if (sb->s_mtd) + sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, sb->s_mtd->index); +#endif /* read the image superblock and check it */ rsb = kmalloc(512, GFP_KERNEL); if (!rsb) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index d96e2f30084b..43953e03c356 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -63,6 +63,7 @@ struct userfaultfd_wait_queue { struct uffd_msg msg; wait_queue_t wq; struct userfaultfd_ctx *ctx; + bool waken; }; struct userfaultfd_wake_range { @@ -86,6 +87,12 @@ static int userfaultfd_wake_function(wait_queue_t *wq, unsigned mode, if (len && (start > uwq->msg.arg.pagefault.address || start + len <= uwq->msg.arg.pagefault.address)) goto out; + WRITE_ONCE(uwq->waken, true); + /* + * The implicit smp_mb__before_spinlock in try_to_wake_up() + * renders uwq->waken visible to other CPUs before the task is + * waken. + */ ret = wake_up_state(wq->private, mode); if (ret) /* @@ -264,6 +271,7 @@ int handle_userfault(struct vm_fault *vmf, unsigned long reason) struct userfaultfd_wait_queue uwq; int ret; bool must_wait, return_to_userland; + long blocking_state; BUG_ON(!rwsem_is_locked(&mm->mmap_sem)); @@ -334,10 +342,13 @@ int handle_userfault(struct vm_fault *vmf, unsigned long reason) uwq.wq.private = current; uwq.msg = userfault_msg(vmf->address, vmf->flags, reason); uwq.ctx = ctx; + uwq.waken = false; return_to_userland = (vmf->flags & (FAULT_FLAG_USER|FAULT_FLAG_KILLABLE)) == (FAULT_FLAG_USER|FAULT_FLAG_KILLABLE); + blocking_state = return_to_userland ? TASK_INTERRUPTIBLE : + TASK_KILLABLE; spin_lock(&ctx->fault_pending_wqh.lock); /* @@ -350,8 +361,7 @@ int handle_userfault(struct vm_fault *vmf, unsigned long reason) * following the spin_unlock to happen before the list_add in * __add_wait_queue. */ - set_current_state(return_to_userland ? TASK_INTERRUPTIBLE : - TASK_KILLABLE); + set_current_state(blocking_state); spin_unlock(&ctx->fault_pending_wqh.lock); must_wait = userfaultfd_must_wait(ctx, vmf->address, vmf->flags, @@ -364,6 +374,29 @@ int handle_userfault(struct vm_fault *vmf, unsigned long reason) wake_up_poll(&ctx->fd_wqh, POLLIN); schedule(); ret |= VM_FAULT_MAJOR; + + /* + * False wakeups can orginate even from rwsem before + * up_read() however userfaults will wait either for a + * targeted wakeup on the specific uwq waitqueue from + * wake_userfault() or for signals or for uffd + * release. + */ + while (!READ_ONCE(uwq.waken)) { + /* + * This needs the full smp_store_mb() + * guarantee as the state write must be + * visible to other CPUs before reading + * uwq.waken from other CPUs. + */ + set_current_state(blocking_state); + if (READ_ONCE(uwq.waken) || + READ_ONCE(ctx->released) || + (return_to_userland ? signal_pending(current) : + fatal_signal_pending(current))) + break; + schedule(); + } } __set_current_state(TASK_RUNNING); |