diff options
| -rw-r--r-- | fs/ext2/ext2.h | 11 | ||||
| -rw-r--r-- | fs/ext2/file.c | 84 | ||||
| -rw-r--r-- | fs/ext2/inode.c | 10 | ||||
| -rw-r--r-- | fs/ext2/super.c | 3 |
4 files changed, 104 insertions, 4 deletions
diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h index 8d15febd0aa3..4c69c94cafd8 100644 --- a/fs/ext2/ext2.h +++ b/fs/ext2/ext2.h @@ -684,6 +684,9 @@ struct ext2_inode_info { struct rw_semaphore xattr_sem; #endif rwlock_t i_meta_lock; +#ifdef CONFIG_FS_DAX + struct rw_semaphore dax_sem; +#endif /* * truncate_mutex is for serialising ext2_truncate() against @@ -699,6 +702,14 @@ struct ext2_inode_info { #endif }; +#ifdef CONFIG_FS_DAX +#define dax_sem_down_write(ext2_inode) down_write(&(ext2_inode)->dax_sem) +#define dax_sem_up_write(ext2_inode) up_write(&(ext2_inode)->dax_sem) +#else +#define dax_sem_down_write(ext2_inode) +#define dax_sem_up_write(ext2_inode) +#endif + /* * Inode dynamic state flags */ diff --git a/fs/ext2/file.c b/fs/ext2/file.c index 1982c3f11aec..11a42c5a09ae 100644 --- a/fs/ext2/file.c +++ b/fs/ext2/file.c @@ -27,27 +27,103 @@ #include "acl.h" #ifdef CONFIG_FS_DAX +/* + * The lock ordering for ext2 DAX fault paths is: + * + * mmap_sem (MM) + * sb_start_pagefault (vfs, freeze) + * ext2_inode_info->dax_sem + * address_space->i_mmap_rwsem or page_lock (mutually exclusive in DAX) + * ext2_inode_info->truncate_mutex + * + * The default page_lock and i_size verification done by non-DAX fault paths + * is sufficient because ext2 doesn't support hole punching. + */ static int ext2_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { - return dax_fault(vma, vmf, ext2_get_block, NULL); + struct inode *inode = file_inode(vma->vm_file); + struct ext2_inode_info *ei = EXT2_I(inode); + int ret; + + if (vmf->flags & FAULT_FLAG_WRITE) { + sb_start_pagefault(inode->i_sb); + file_update_time(vma->vm_file); + } + down_read(&ei->dax_sem); + + ret = __dax_fault(vma, vmf, ext2_get_block, NULL); + + up_read(&ei->dax_sem); + if (vmf->flags & FAULT_FLAG_WRITE) + sb_end_pagefault(inode->i_sb); + return ret; } static int ext2_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmd, unsigned int flags) { - return dax_pmd_fault(vma, addr, pmd, flags, ext2_get_block, NULL); + struct inode *inode = file_inode(vma->vm_file); + struct ext2_inode_info *ei = EXT2_I(inode); + int ret; + + if (flags & FAULT_FLAG_WRITE) { + sb_start_pagefault(inode->i_sb); + file_update_time(vma->vm_file); + } + down_read(&ei->dax_sem); + + ret = __dax_pmd_fault(vma, addr, pmd, flags, ext2_get_block, NULL); + + up_read(&ei->dax_sem); + if (flags & FAULT_FLAG_WRITE) + sb_end_pagefault(inode->i_sb); + return ret; } static int ext2_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) { - return dax_mkwrite(vma, vmf, ext2_get_block, NULL); + struct inode *inode = file_inode(vma->vm_file); + struct ext2_inode_info *ei = EXT2_I(inode); + int ret; + + sb_start_pagefault(inode->i_sb); + file_update_time(vma->vm_file); + down_read(&ei->dax_sem); + + ret = __dax_mkwrite(vma, vmf, ext2_get_block, NULL); + + up_read(&ei->dax_sem); + sb_end_pagefault(inode->i_sb); + return ret; +} + +static int ext2_dax_pfn_mkwrite(struct vm_area_struct *vma, + struct vm_fault *vmf) +{ + struct inode *inode = file_inode(vma->vm_file); + struct ext2_inode_info *ei = EXT2_I(inode); + int ret = VM_FAULT_NOPAGE; + loff_t size; + + sb_start_pagefault(inode->i_sb); + file_update_time(vma->vm_file); + down_read(&ei->dax_sem); + + /* check that the faulting page hasn't raced with truncate */ + size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; + if (vmf->pgoff >= size) + ret = VM_FAULT_SIGBUS; + + up_read(&ei->dax_sem); + sb_end_pagefault(inode->i_sb); + return ret; } static const struct vm_operations_struct ext2_dax_vm_ops = { .fault = ext2_dax_fault, .pmd_fault = ext2_dax_pmd_fault, .page_mkwrite = ext2_dax_mkwrite, - .pfn_mkwrite = dax_pfn_mkwrite, + .pfn_mkwrite = ext2_dax_pfn_mkwrite, }; static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma) diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index c60a248c640c..0aa9bf6e6e53 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -1085,6 +1085,7 @@ static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int de ext2_free_data(inode, p, q); } +/* dax_sem must be held when calling this function */ static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) { __le32 *i_data = EXT2_I(inode)->i_data; @@ -1100,6 +1101,10 @@ static void __ext2_truncate_blocks(struct inode *inode, loff_t offset) blocksize = inode->i_sb->s_blocksize; iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); +#ifdef CONFIG_FS_DAX + WARN_ON(!rwsem_is_locked(&ei->dax_sem)); +#endif + n = ext2_block_to_path(inode, iblock, offsets, NULL); if (n == 0) return; @@ -1185,7 +1190,10 @@ static void ext2_truncate_blocks(struct inode *inode, loff_t offset) return; if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) return; + + dax_sem_down_write(EXT2_I(inode)); __ext2_truncate_blocks(inode, offset); + dax_sem_up_write(EXT2_I(inode)); } static int ext2_setsize(struct inode *inode, loff_t newsize) @@ -1213,8 +1221,10 @@ static int ext2_setsize(struct inode *inode, loff_t newsize) if (error) return error; + dax_sem_down_write(EXT2_I(inode)); truncate_setsize(inode, newsize); __ext2_truncate_blocks(inode, newsize); + dax_sem_up_write(EXT2_I(inode)); inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; if (inode_needs_sync(inode)) { diff --git a/fs/ext2/super.c b/fs/ext2/super.c index 900e19cf9ef6..3a71cea68420 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -192,6 +192,9 @@ static void init_once(void *foo) init_rwsem(&ei->xattr_sem); #endif mutex_init(&ei->truncate_mutex); +#ifdef CONFIG_FS_DAX + init_rwsem(&ei->dax_sem); +#endif inode_init_once(&ei->vfs_inode); } |