diff options
Diffstat (limited to 'fs/ext4/file.c')
| -rw-r--r-- | fs/ext4/file.c | 102 |
1 files changed, 69 insertions, 33 deletions
diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 113837e7ba98..1126436dada1 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -113,7 +113,7 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from) ext4_unwritten_wait(inode); } - mutex_lock(&inode->i_mutex); + inode_lock(inode); ret = generic_write_checks(iocb, from); if (ret <= 0) goto out; @@ -169,7 +169,7 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from) } ret = __generic_file_write_iter(iocb, from); - mutex_unlock(&inode->i_mutex); + inode_unlock(inode); if (ret > 0) { ssize_t err; @@ -186,50 +186,42 @@ ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from) return ret; out: - mutex_unlock(&inode->i_mutex); + inode_unlock(inode); if (aio_mutex) mutex_unlock(aio_mutex); return ret; } #ifdef CONFIG_FS_DAX -static void ext4_end_io_unwritten(struct buffer_head *bh, int uptodate) -{ - struct inode *inode = bh->b_assoc_map->host; - /* XXX: breaks on 32-bit > 16TB. Is that even supported? */ - loff_t offset = (loff_t)(uintptr_t)bh->b_private << inode->i_blkbits; - int err; - if (!uptodate) - return; - WARN_ON(!buffer_unwritten(bh)); - err = ext4_convert_unwritten_extents(NULL, inode, offset, bh->b_size); -} - static int ext4_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { int result; handle_t *handle = NULL; - struct super_block *sb = file_inode(vma->vm_file)->i_sb; + struct inode *inode = file_inode(vma->vm_file); + struct super_block *sb = inode->i_sb; bool write = vmf->flags & FAULT_FLAG_WRITE; if (write) { sb_start_pagefault(sb); file_update_time(vma->vm_file); + down_read(&EXT4_I(inode)->i_mmap_sem); handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE, EXT4_DATA_TRANS_BLOCKS(sb)); - } + } else + down_read(&EXT4_I(inode)->i_mmap_sem); if (IS_ERR(handle)) result = VM_FAULT_SIGBUS; else - result = __dax_fault(vma, vmf, ext4_get_block_dax, - ext4_end_io_unwritten); + result = __dax_fault(vma, vmf, ext4_dax_mmap_get_block, NULL); if (write) { if (!IS_ERR(handle)) ext4_journal_stop(handle); + up_read(&EXT4_I(inode)->i_mmap_sem); sb_end_pagefault(sb); - } + } else + up_read(&EXT4_I(inode)->i_mmap_sem); return result; } @@ -246,44 +238,88 @@ static int ext4_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr, if (write) { sb_start_pagefault(sb); file_update_time(vma->vm_file); + down_read(&EXT4_I(inode)->i_mmap_sem); handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE, ext4_chunk_trans_blocks(inode, PMD_SIZE / PAGE_SIZE)); - } + } else + down_read(&EXT4_I(inode)->i_mmap_sem); if (IS_ERR(handle)) result = VM_FAULT_SIGBUS; else result = __dax_pmd_fault(vma, addr, pmd, flags, - ext4_get_block_dax, ext4_end_io_unwritten); + ext4_dax_mmap_get_block, NULL); if (write) { if (!IS_ERR(handle)) ext4_journal_stop(handle); + up_read(&EXT4_I(inode)->i_mmap_sem); sb_end_pagefault(sb); - } + } else + up_read(&EXT4_I(inode)->i_mmap_sem); return result; } static int ext4_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) { - return dax_mkwrite(vma, vmf, ext4_get_block_dax, - ext4_end_io_unwritten); + int err; + struct inode *inode = file_inode(vma->vm_file); + + sb_start_pagefault(inode->i_sb); + file_update_time(vma->vm_file); + down_read(&EXT4_I(inode)->i_mmap_sem); + err = __dax_mkwrite(vma, vmf, ext4_dax_mmap_get_block, NULL); + up_read(&EXT4_I(inode)->i_mmap_sem); + sb_end_pagefault(inode->i_sb); + + return err; +} + +/* + * Handle write fault for VM_MIXEDMAP mappings. Similarly to ext4_dax_mkwrite() + * handler we check for races agaist truncate. Note that since we cycle through + * i_mmap_sem, we are sure that also any hole punching that began before we + * were called is finished by now and so if it included part of the file we + * are working on, our pte will get unmapped and the check for pte_same() in + * wp_pfn_shared() fails. Thus fault gets retried and things work out as + * desired. + */ +static int ext4_dax_pfn_mkwrite(struct vm_area_struct *vma, + struct vm_fault *vmf) +{ + struct inode *inode = file_inode(vma->vm_file); + struct super_block *sb = inode->i_sb; + loff_t size; + int ret; + + sb_start_pagefault(sb); + file_update_time(vma->vm_file); + down_read(&EXT4_I(inode)->i_mmap_sem); + size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; + if (vmf->pgoff >= size) + ret = VM_FAULT_SIGBUS; + else + ret = dax_pfn_mkwrite(vma, vmf); + up_read(&EXT4_I(inode)->i_mmap_sem); + sb_end_pagefault(sb); + + return ret; } static const struct vm_operations_struct ext4_dax_vm_ops = { .fault = ext4_dax_fault, .pmd_fault = ext4_dax_pmd_fault, .page_mkwrite = ext4_dax_mkwrite, - .pfn_mkwrite = dax_pfn_mkwrite, + .pfn_mkwrite = ext4_dax_pfn_mkwrite, }; #else #define ext4_dax_vm_ops ext4_file_vm_ops #endif static const struct vm_operations_struct ext4_file_vm_ops = { - .fault = filemap_fault, + .fault = ext4_filemap_fault, .map_pages = filemap_map_pages, .page_mkwrite = ext4_page_mkwrite, }; @@ -527,11 +563,11 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize) int blkbits; int ret = 0; - mutex_lock(&inode->i_mutex); + inode_lock(inode); isize = i_size_read(inode); if (offset >= isize) { - mutex_unlock(&inode->i_mutex); + inode_unlock(inode); return -ENXIO; } @@ -579,7 +615,7 @@ static loff_t ext4_seek_data(struct file *file, loff_t offset, loff_t maxsize) dataoff = (loff_t)last << blkbits; } while (last <= end); - mutex_unlock(&inode->i_mutex); + inode_unlock(inode); if (dataoff > isize) return -ENXIO; @@ -600,11 +636,11 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize) int blkbits; int ret = 0; - mutex_lock(&inode->i_mutex); + inode_lock(inode); isize = i_size_read(inode); if (offset >= isize) { - mutex_unlock(&inode->i_mutex); + inode_unlock(inode); return -ENXIO; } @@ -655,7 +691,7 @@ static loff_t ext4_seek_hole(struct file *file, loff_t offset, loff_t maxsize) break; } while (last <= end); - mutex_unlock(&inode->i_mutex); + inode_unlock(inode); if (holeoff > isize) holeoff = isize; |