From: Pavel Shilovsky <[email protected]> Read from the cache if we have at least Level II oplock - otherwise read from the server. Add cifs_user_readv to let the client read into several buffers.
Signed-off-by: Pavel Shilovsky <[email protected]> --- fs/cifs/cifsfs.c | 38 ++++++++++++++++++- fs/cifs/cifsfs.h | 4 +- fs/cifs/file.c | 108 +++++++++++++++++++++++++++++++++++++++--------------- 3 files changed, 117 insertions(+), 33 deletions(-) diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index a218afe..bcb4d2c 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -572,6 +572,40 @@ cifs_do_mount(struct file_system_type *fs_type, return dget(sb->s_root); } +static ssize_t cifs_strict_read(struct kiocb *iocb, const struct iovec *iov, + unsigned long nr_segs, loff_t pos) +{ + struct inode *inode; + struct cifs_sb_info *cifs_sb; + ssize_t read = 0; + + if (!nr_segs) + return read; + + inode = iocb->ki_filp->f_path.dentry->d_inode; + cifs_sb = CIFS_SB(iocb->ki_filp->f_path.dentry->d_sb); + + if (CIFS_I(inode)->clientCanCacheRead) + return generic_file_aio_read(iocb, iov, nr_segs, pos); + + /* + * In strict cache mode we need to read from the server all the time + * if we don't have level II oplock because the server can delay mtime + * change - so we can't make a decision about inode invalidating. + * And we can also fail with pagereading if there are mandatory locks + * on pages affected by this read but not on the region from pos to + * pos+len-1. + */ + + read = cifs_user_readv(iocb->ki_filp, iov, nr_segs, &pos); + if (read < 0) + return read; + + iocb->ki_pos = pos; + + return read; +} + static ssize_t cifs_file_aio_write(struct kiocb *iocb, const struct iovec *iov, unsigned long nr_segs, loff_t pos) { @@ -713,7 +747,7 @@ const struct file_operations cifs_file_ops = { const struct file_operations cifs_file_strict_ops = { .read = do_sync_read, .write = do_sync_write, - .aio_read = generic_file_aio_read, + .aio_read = cifs_strict_read, .aio_write = cifs_file_aio_write, .open = cifs_open, .release = cifs_close, @@ -769,7 +803,7 @@ const struct file_operations cifs_file_nobrl_ops = { const struct file_operations cifs_file_strict_nobrl_ops = { .read = do_sync_read, .write = do_sync_write, - .aio_read = generic_file_aio_read, + .aio_read = cifs_strict_read, .aio_write = cifs_file_aio_write, .open = cifs_open, .release = cifs_close, diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h index 657738f..f690d1c 100644 --- a/fs/cifs/cifsfs.h +++ b/fs/cifs/cifsfs.h @@ -81,7 +81,9 @@ extern int cifs_open(struct inode *inode, struct file *file); extern int cifs_close(struct inode *inode, struct file *file); extern int cifs_closedir(struct inode *inode, struct file *file); extern ssize_t cifs_user_read(struct file *file, char __user *read_data, - size_t read_size, loff_t *poffset); + size_t read_size, loff_t *poffset); +extern ssize_t cifs_user_readv(struct file *file, const struct iovec *iov, + unsigned long nr_segs, loff_t *poffset); extern ssize_t cifs_user_write(struct file *file, const char __user *write_data, size_t write_size, loff_t *poffset); extern int cifs_lock(struct file *, int, struct file_lock *); diff --git a/fs/cifs/file.c b/fs/cifs/file.c index d48723c..bc53e9e 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -1677,20 +1677,60 @@ int cifs_flush(struct file *file, fl_owner_t id) return rc; } -ssize_t cifs_user_read(struct file *file, char __user *read_data, - size_t read_size, loff_t *poffset) +static int +cifs_fill_iov(const struct iovec *iov, unsigned long nr_segs, + unsigned long *last_len, unsigned long *last_ind, char *data, + size_t datalen) { - int rc = -EACCES; - unsigned int bytes_read = 0; - unsigned int total_read = 0; - unsigned int current_read_size; + const struct iovec *ciov; + unsigned long cur_len; + + while (datalen) { + cur_len = min_t(unsigned long, datalen, + *last_len); + ciov = &iov[*last_ind]; + + if (copy_to_user(ciov->iov_base + (ciov->iov_len - *last_len), + data, cur_len)) + return -EFAULT; + + datalen -= cur_len; + data += cur_len; + + *last_len -= cur_len; + if (*last_len == 0) { + (*last_ind)++; + *last_len = iov[*last_ind].iov_len; + } + } + + return 0; +} + +ssize_t cifs_user_readv(struct file *file, const struct iovec *iov, + unsigned long nr_segs, loff_t *poffset) +{ + int rc; + int xid; + unsigned int bytes_read = 0, total_read = 0; + unsigned long last_len = 0, len = 0, last_ind = 0; + unsigned long cur_len, i; struct cifs_sb_info *cifs_sb; struct cifsTconInfo *pTcon; - int xid; struct cifsFileInfo *open_file; - char *smb_read_data; - char __user *current_offset; struct smb_com_read_rsp *pSMBr; + char *read_data; + + if (!nr_segs) + return 0; + + last_len = iov->iov_len; + + for (i = 0; i < nr_segs; i++) + len += iov[i].iov_len; + + if (!len) + return 0; xid = GetXid(); cifs_sb = CIFS_SB(file->f_path.dentry->d_sb); @@ -1700,19 +1740,19 @@ ssize_t cifs_user_read(struct file *file, char __user *read_data, FreeXid(xid); return rc; } + open_file = file->private_data; pTcon = tlink_tcon(open_file->tlink); if ((file->f_flags & O_ACCMODE) == O_WRONLY) cFYI(1, "attempting read on write only file instance"); - for (total_read = 0, current_offset = read_data; - read_size > total_read; - total_read += bytes_read, current_offset += bytes_read) { - current_read_size = min_t(const int, read_size - total_read, + for (total_read = 0; total_read < len; total_read += bytes_read) { + cur_len = min_t(const int, len - total_read, cifs_sb->rsize); rc = -EAGAIN; - smb_read_data = NULL; + read_data = NULL; + while (rc == -EAGAIN) { int buf_type = CIFS_NO_BUFFER; if (open_file->invalidHandle) { @@ -1721,26 +1761,24 @@ ssize_t cifs_user_read(struct file *file, char __user *read_data, break; } rc = CIFSSMBRead(xid, pTcon, - open_file->netfid, - current_read_size, *poffset, - &bytes_read, &smb_read_data, - &buf_type); - pSMBr = (struct smb_com_read_rsp *)smb_read_data; - if (smb_read_data) { - if (copy_to_user(current_offset, - smb_read_data + - 4 /* RFC1001 length field */ + - le16_to_cpu(pSMBr->DataOffset), - bytes_read)) + open_file->netfid, cur_len, *poffset, + &bytes_read, &read_data, &buf_type); + pSMBr = (struct smb_com_read_rsp *)read_data; + if (read_data) { + char *data_offset = read_data + 4 + + le16_to_cpu(pSMBr->DataOffset); + if (cifs_fill_iov(iov, nr_segs, + &last_len, &last_ind, + data_offset, bytes_read)) rc = -EFAULT; - if (buf_type == CIFS_SMALL_BUFFER) - cifs_small_buf_release(smb_read_data); + cifs_small_buf_release(read_data); else if (buf_type == CIFS_LARGE_BUFFER) - cifs_buf_release(smb_read_data); - smb_read_data = NULL; + cifs_buf_release(read_data); + read_data = NULL; } } + if (rc || (bytes_read == 0)) { if (total_read) { break; @@ -1753,13 +1791,23 @@ ssize_t cifs_user_read(struct file *file, char __user *read_data, *poffset += bytes_read; } } + FreeXid(xid); return total_read; } +ssize_t cifs_user_read(struct file *file, char __user *read_data, + size_t read_size, loff_t *poffset) +{ + struct iovec iov; + iov.iov_base = read_data; + iov.iov_len = read_size; + + return cifs_user_readv(file, &iov, 1, poffset); +} static ssize_t cifs_read(struct file *file, char *read_data, size_t read_size, - loff_t *poffset) + loff_t *poffset) { int rc = -EACCES; unsigned int bytes_read = 0; -- 1.7.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
