diff options
Diffstat (limited to 'fs/fuse/file.c')
-rw-r--r-- | fs/fuse/file.c | 66 |
1 files changed, 48 insertions, 18 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index fdff7bf4fa4f..c053266235e2 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -18,6 +18,7 @@ #include <linux/swap.h> #include <linux/falloc.h> #include <linux/uio.h> +#include <linux/fs.h> static int fuse_send_open(struct fuse_conn *fc, u64 nodeid, struct file *file, int opcode, struct fuse_open_out *outargp) @@ -201,7 +202,7 @@ int fuse_open_common(struct inode *inode, struct file *file, bool isdir) { struct fuse_conn *fc = get_fuse_conn(inode); int err; - bool lock_inode = (file->f_flags & O_TRUNC) && + bool is_wb_truncate = (file->f_flags & O_TRUNC) && fc->atomic_o_trunc && fc->writeback_cache; @@ -209,16 +210,20 @@ int fuse_open_common(struct inode *inode, struct file *file, bool isdir) if (err) return err; - if (lock_inode) + if (is_wb_truncate) { inode_lock(inode); + fuse_set_nowrite(inode); + } err = fuse_do_open(fc, get_node_id(inode), file, isdir); if (!err) fuse_finish_open(inode, file); - if (lock_inode) + if (is_wb_truncate) { + fuse_release_nowrite(inode); inode_unlock(inode); + } return err; } @@ -2002,10 +2007,8 @@ static int fuse_writepages(struct address_space *mapping, err = write_cache_pages(mapping, wbc, fuse_writepages_fill, &data); if (data.req) { - /* Ignore errors if we can write at least one page */ BUG_ON(!data.req->num_pages); fuse_writepages_send(&data); - err = 0; } if (data.ff) fuse_file_put(data.ff, false, false); @@ -2612,7 +2615,16 @@ long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg, struct iovec *iov = iov_page; iov->iov_base = (void __user *)arg; - iov->iov_len = _IOC_SIZE(cmd); + + switch (cmd) { + case FS_IOC_GETFLAGS: + case FS_IOC_SETFLAGS: + iov->iov_len = sizeof(int); + break; + default: + iov->iov_len = _IOC_SIZE(cmd); + break; + } if (_IOC_DIR(cmd) & _IOC_WRITE) { in_iov = iov; @@ -3143,21 +3155,35 @@ static ssize_t fuse_copy_file_range(struct file *file_in, loff_t pos_in, if (fc->no_copy_file_range) return -EOPNOTSUPP; - if (fc->writeback_cache) { - inode_lock(inode_in); - err = fuse_writeback_range(inode_in, pos_in, pos_in + len); - inode_unlock(inode_in); - if (err) - return err; - } + inode_lock(inode_in); + err = fuse_writeback_range(inode_in, pos_in, pos_in + len - 1); + inode_unlock(inode_in); + if (err) + return err; inode_lock(inode_out); - if (fc->writeback_cache) { - err = fuse_writeback_range(inode_out, pos_out, pos_out + len); - if (err) - goto out; - } + /* + * Write out dirty pages in the destination file before sending the COPY + * request to userspace. After the request is completed, truncate off + * pages (including partial ones) from the cache that have been copied, + * since these contain stale data at that point. + * + * This should be mostly correct, but if the COPY writes to partial + * pages (at the start or end) and the parts not covered by the COPY are + * written through a memory map after calling fuse_writeback_range(), + * then these partial page modifications will be lost on truncation. + * + * It is unlikely that someone would rely on such mixed style + * modifications. Yet this does give less guarantees than if the + * copying was performed with write(2). + * + * To fix this a i_mmap_sem style lock could be used to prevent new + * faults while the copy is ongoing. + */ + err = fuse_writeback_range(inode_out, pos_out, pos_out + len - 1); + if (err) + goto out; if (is_unstable) set_bit(FUSE_I_SIZE_UNSTABLE, &fi_out->state); @@ -3178,6 +3204,10 @@ static ssize_t fuse_copy_file_range(struct file *file_in, loff_t pos_in, if (err) goto out; + truncate_inode_pages_range(inode_out->i_mapping, + ALIGN_DOWN(pos_out, PAGE_SIZE), + ALIGN(pos_out + outarg.size, PAGE_SIZE) - 1); + if (fc->writeback_cache) { fuse_write_update_size(inode_out, pos_out + outarg.size); file_update_time(file_out); |