diff options
| -rw-r--r-- | arch/i386/kernel/syscall_table.S | 1 | ||||
| -rw-r--r-- | fs/Makefile | 2 | ||||
| -rw-r--r-- | fs/sync.c | 164 | ||||
| -rw-r--r-- | include/asm-i386/unistd.h | 3 | ||||
| -rw-r--r-- | include/linux/fadvise.h | 6 | ||||
| -rw-r--r-- | include/linux/fs.h | 7 | ||||
| -rw-r--r-- | include/linux/syscalls.h | 2 | ||||
| -rw-r--r-- | mm/fadvise.c | 20 |
8 files changed, 177 insertions, 28 deletions
diff --git a/arch/i386/kernel/syscall_table.S b/arch/i386/kernel/syscall_table.S index ce3ef4fa055..4f58b9c0efe 100644 --- a/arch/i386/kernel/syscall_table.S +++ b/arch/i386/kernel/syscall_table.S @@ -313,3 +313,4 @@ ENTRY(sys_call_table) .long sys_set_robust_list .long sys_get_robust_list .long sys_splice + .long sys_sync_file_range diff --git a/fs/Makefile b/fs/Makefile index f3a4f707717..83bf478e786 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -10,7 +10,7 @@ obj-y := open.o read_write.o file_table.o buffer.o bio.o super.o \ ioctl.o readdir.o select.o fifo.o locks.o dcache.o inode.o \ attr.o bad_inode.o file.o filesystems.o namespace.o aio.o \ seq_file.o xattr.o libfs.o fs-writeback.o mpage.o direct-io.o \ - ioprio.o pnode.o drop_caches.o splice.o + ioprio.o pnode.o drop_caches.o splice.o sync.o obj-$(CONFIG_INOTIFY) += inotify.o obj-$(CONFIG_EPOLL) += eventpoll.o diff --git a/fs/sync.c b/fs/sync.c new file mode 100644 index 00000000000..8616006d209 --- /dev/null +++ b/fs/sync.c @@ -0,0 +1,164 @@ +/* + * High-level sync()-related operations + */ + +#include <linux/kernel.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/module.h> +#include <linux/writeback.h> +#include <linux/syscalls.h> +#include <linux/linkage.h> +#include <linux/pagemap.h> + +#define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \ + SYNC_FILE_RANGE_WAIT_AFTER) + +/* + * sys_sync_file_range() permits finely controlled syncing over a segment of + * a file in the range offset .. (offset+nbytes-1) inclusive. If nbytes is + * zero then sys_sync_file_range() will operate from offset out to EOF. + * + * The flag bits are: + * + * SYNC_FILE_RANGE_WAIT_BEFORE: wait upon writeout of all pages in the range + * before performing the write. + * + * SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the + * range which are not presently under writeback. + * + * SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range + * after performing the write. + * + * Useful combinations of the flag bits are: + * + * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE: ensures that all pages + * in the range which were dirty on entry to sys_sync_file_range() are placed + * under writeout. This is a start-write-for-data-integrity operation. + * + * SYNC_FILE_RANGE_WRITE: start writeout of all dirty pages in the range which + * are not presently under writeout. This is an asynchronous flush-to-disk + * operation. Not suitable for data integrity operations. + * + * SYNC_FILE_RANGE_WAIT_BEFORE (or SYNC_FILE_RANGE_WAIT_AFTER): wait for + * completion of writeout of all pages in the range. This will be used after an + * earlier SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE operation to wait + * for that operation to complete and to return the result. + * + * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE|SYNC_FILE_RANGE_WAIT_AFTER: + * a traditional sync() operation. This is a write-for-data-integrity operation + * which will ensure that all pages in the range which were dirty on entry to + * sys_sync_file_range() are committed to disk. + * + * + * SYNC_FILE_RANGE_WAIT_BEFORE and SYNC_FILE_RANGE_WAIT_AFTER will detect any + * I/O errors or ENOSPC conditions and will return those to the caller, after + * clearing the EIO and ENOSPC flags in the address_space. + * + * It should be noted that none of these operations write out the file's + * metadata. So unless the application is strictly performing overwrites of + * already-instantiated disk blocks, there are no guarantees here that the data + * will be available after a crash. + */ +asmlinkage long sys_sync_file_range(int fd, loff_t offset, loff_t nbytes, + int flags) +{ + int ret; + struct file *file; + loff_t endbyte; /* inclusive */ + int fput_needed; + umode_t i_mode; + + ret = -EINVAL; + if (flags & ~VALID_FLAGS) + goto out; + + endbyte = offset + nbytes; + + if ((s64)offset < 0) + goto out; + if ((s64)endbyte < 0) + goto out; + if (endbyte < offset) + goto out; + + if (sizeof(pgoff_t) == 4) { + if (offset >= (0x100000000ULL << PAGE_CACHE_SHIFT)) { + /* + * The range starts outside a 32 bit machine's + * pagecache addressing capabilities. Let it "succeed" + */ + ret = 0; + goto out; + } + if (endbyte >= (0x100000000ULL << PAGE_CACHE_SHIFT)) { + /* + * Out to EOF + */ + nbytes = 0; + } + } + + if (nbytes == 0) + endbyte = -1; + else + endbyte--; /* inclusive */ + + ret = -EBADF; + file = fget_light(fd, &fput_needed); + if (!file) + goto out; + + i_mode = file->f_dentry->d_inode->i_mode; + ret = -ESPIPE; + if (!S_ISREG(i_mode) && !S_ISBLK(i_mode) && !S_ISDIR(i_mode) && + !S_ISLNK(i_mode)) + goto out_put; + + ret = do_sync_file_range(file, offset, endbyte, flags); +out_put: + fput_light(file, fput_needed); +out: + return ret; +} + +/* + * `endbyte' is inclusive + */ +int do_sync_file_range(struct file *file, loff_t offset, loff_t endbyte, + int flags) +{ + int ret; + struct address_space *mapping; + + mapping = file->f_mapping; + if (!mapping) { + ret = -EINVAL; + goto out; + } + + ret = 0; + if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) { + ret = wait_on_page_writeback_range(mapping, + offset >> PAGE_CACHE_SHIFT, + endbyte >> PAGE_CACHE_SHIFT); + if (ret < 0) + goto out; + } + + if (flags & SYNC_FILE_RANGE_WRITE) { + ret = __filemap_fdatawrite_range(mapping, offset, endbyte, + WB_SYNC_NONE); + if (ret < 0) + goto out; + } + + if (flags & SYNC_FILE_RANGE_WAIT_AFTER) { + ret = wait_on_page_writeback_range(mapping, + offset >> PAGE_CACHE_SHIFT, + endbyte >> PAGE_CACHE_SHIFT); + } +out: + return ret; +} +EXPORT_SYMBOL_GPL(do_sync_file_range); diff --git a/include/asm-i386/unistd.h b/include/asm-i386/unistd.h index 789e9bdd0a4..2e7f3e257fd 100644 --- a/include/asm-i386/unistd.h +++ b/include/asm-i386/unistd.h @@ -319,8 +319,9 @@ #define __NR_set_robust_list 311 #define __NR_get_robust_list 312 #define __NR_sys_splice 313 +#define __NR_sys_sync_file_range 314 -#define NR_syscalls 314 +#define NR_syscalls 315 /* * user-visible error numbers are in the range -1 - -128: see diff --git a/include/linux/fadvise.h b/include/linux/fadvise.h index b2913bba35d..e8e747139b9 100644 --- a/include/linux/fadvise.h +++ b/include/linux/fadvise.h @@ -18,10 +18,4 @@ #define POSIX_FADV_NOREUSE 5 /* Data will be accessed once. */ #endif -/* - * Linux-specific fadvise() extensions: - */ -#define LINUX_FADV_ASYNC_WRITE 32 /* Start writeout on range */ -#define LINUX_FADV_WRITE_WAIT 33 /* Wait upon writeout to range */ - #endif /* FADVISE_H_INCLUDED */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 20a7afd4590..4ed7e602d70 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -757,6 +757,13 @@ extern void send_sigio(struct fown_struct *fown, int fd, int band); extern int fcntl_setlease(unsigned int fd, struct file *filp, long arg); extern int fcntl_getlease(struct file *filp); +/* fs/sync.c */ +#define SYNC_FILE_RANGE_WAIT_BEFORE 1 +#define SYNC_FILE_RANGE_WRITE 2 +#define SYNC_FILE_RANGE_WAIT_AFTER 4 +extern int do_sync_file_range(struct file *file, loff_t offset, loff_t endbyte, + int flags); + /* fs/locks.c */ extern void locks_init_lock(struct file_lock *); extern void locks_copy_lock(struct file_lock *, struct file_lock *); diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index e78ffc7d5b5..5717147596b 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -571,5 +571,7 @@ asmlinkage long compat_sys_openat(unsigned int dfd, const char __user *filename, asmlinkage long sys_unshare(unsigned long unshare_flags); asmlinkage long sys_splice(int fdin, int fdout, size_t len, unsigned int flags); +asmlinkage long sys_sync_file_range(int fd, loff_t offset, loff_t nbytes, + int flags); #endif diff --git a/mm/fadvise.c b/mm/fadvise.c index 907c39257ca..0a03357a1f8 100644 --- a/mm/fadvise.c +++ b/mm/fadvise.c @@ -35,17 +35,6 @@ * * LINUX_FADV_ASYNC_WRITE: push some or all of the dirty pages at the disk. * - * LINUX_FADV_WRITE_WAIT, LINUX_FADV_ASYNC_WRITE: push all of the currently - * dirty pages at the disk. - * - * LINUX_FADV_WRITE_WAIT, LINUX_FADV_ASYNC_WRITE, LINUX_FADV_WRITE_WAIT: push - * all of the currently dirty pages at the disk, wait until they have been - * written. - * - * It should be noted that none of these operations write out the file's - * metadata. So unless the application is strictly performing overwrites of - * already-instantiated disk blocks, there are no guarantees here that the data - * will be available after a crash. */ asmlinkage long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice) { @@ -129,15 +118,6 @@ asmlinkage long sys_fadvise64_64(int fd, loff_t offset, loff_t len, int advice) invalidate_mapping_pages(mapping, start_index, end_index); break; - case LINUX_FADV_ASYNC_WRITE: - ret = __filemap_fdatawrite_range(mapping, offset, endbyte, - WB_SYNC_NONE); - break; - case LINUX_FADV_WRITE_WAIT: - ret = wait_on_page_writeback_range(mapping, - offset >> PAGE_CACHE_SHIFT, - endbyte >> PAGE_CACHE_SHIFT); - break; default: ret = -EINVAL; } |