From 067c054fb9c90811ae38898ce649f8dafa13354c Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 14 Jun 2020 19:04:42 -0400 Subject: dlmfs: clean up dlmfs_file_{read,write}() a bit The damn file is constant-sized - 64 bytes. IOW, * i_size_read() is pointless * so's dynamic allocation * so's the 'size' argument of user_dlm_read_lvb() * ... and so's open-coding simple_read_from_buffer(), while we are at it. Signed-off-by: Al Viro --- fs/ocfs2/dlmfs/dlmfs.c | 52 ++++++++---------------------------------------- fs/ocfs2/dlmfs/userdlm.c | 12 ++++------- fs/ocfs2/dlmfs/userdlm.h | 4 +--- 3 files changed, 13 insertions(+), 55 deletions(-) (limited to 'fs/ocfs2') diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c index ea868c6f9800..583820ec63e2 100644 --- a/fs/ocfs2/dlmfs/dlmfs.c +++ b/fs/ocfs2/dlmfs/dlmfs.c @@ -221,47 +221,17 @@ static __poll_t dlmfs_file_poll(struct file *file, poll_table *wait) return event; } -static ssize_t dlmfs_file_read(struct file *filp, +static ssize_t dlmfs_file_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { - int bytes_left; - ssize_t got; - char *lvb_buf; - struct inode *inode = file_inode(filp); - - mlog(0, "inode %lu, count = %zu, *ppos = %llu\n", - inode->i_ino, count, *ppos); + char lvb[DLM_LVB_LEN]; - if (*ppos >= i_size_read(inode)) + if (!user_dlm_read_lvb(file_inode(file), lvb)) return 0; - /* don't read past the lvb */ - if (count > i_size_read(inode) - *ppos) - count = i_size_read(inode) - *ppos; - - if (!count) - return 0; - - lvb_buf = kmalloc(count, GFP_NOFS); - if (!lvb_buf) - return -ENOMEM; - - got = user_dlm_read_lvb(inode, lvb_buf, count); - if (got) { - BUG_ON(got != count); - bytes_left = copy_to_user(buf, lvb_buf, count); - count -= bytes_left; - } else - count = 0; - - kfree(lvb_buf); - - *ppos = *ppos + count; - - mlog(0, "read %zu bytes\n", count); - return count; + return simple_read_from_buffer(buf, count, ppos, lvb, sizeof(lvb)); } static ssize_t dlmfs_file_write(struct file *filp, @@ -269,34 +239,28 @@ static ssize_t dlmfs_file_write(struct file *filp, size_t count, loff_t *ppos) { + char lvb_buf[DLM_LVB_LEN]; int bytes_left; - char *lvb_buf; struct inode *inode = file_inode(filp); mlog(0, "inode %lu, count = %zu, *ppos = %llu\n", inode->i_ino, count, *ppos); - if (*ppos >= i_size_read(inode)) + if (*ppos >= DLM_LVB_LEN) return -ENOSPC; /* don't write past the lvb */ - if (count > i_size_read(inode) - *ppos) - count = i_size_read(inode) - *ppos; + if (count > DLM_LVB_LEN - *ppos) + count = DLM_LVB_LEN - *ppos; if (!count) return 0; - lvb_buf = kmalloc(count, GFP_NOFS); - if (!lvb_buf) - return -ENOMEM; - bytes_left = copy_from_user(lvb_buf, buf, count); count -= bytes_left; if (count) user_dlm_write_lvb(inode, lvb_buf, count); - kfree(lvb_buf); - *ppos = *ppos + count; mlog(0, "wrote %zu bytes\n", count); return count; diff --git a/fs/ocfs2/dlmfs/userdlm.c b/fs/ocfs2/dlmfs/userdlm.c index 3df5be25bfb1..339f098d9592 100644 --- a/fs/ocfs2/dlmfs/userdlm.c +++ b/fs/ocfs2/dlmfs/userdlm.c @@ -547,24 +547,20 @@ void user_dlm_write_lvb(struct inode *inode, spin_unlock(&lockres->l_lock); } -ssize_t user_dlm_read_lvb(struct inode *inode, - char *val, - unsigned int len) +bool user_dlm_read_lvb(struct inode *inode, char *val) { struct user_lock_res *lockres = &DLMFS_I(inode)->ip_lockres; char *lvb; - ssize_t ret = len; - - BUG_ON(len > DLM_LVB_LEN); + bool ret = true; spin_lock(&lockres->l_lock); BUG_ON(lockres->l_level < DLM_LOCK_PR); if (ocfs2_dlm_lvb_valid(&lockres->l_lksb)) { lvb = ocfs2_dlm_lvb(&lockres->l_lksb); - memcpy(val, lvb, len); + memcpy(val, lvb, DLM_LVB_LEN); } else - ret = 0; + ret = false; spin_unlock(&lockres->l_lock); return ret; diff --git a/fs/ocfs2/dlmfs/userdlm.h b/fs/ocfs2/dlmfs/userdlm.h index 4bef7cdef859..0558ae768200 100644 --- a/fs/ocfs2/dlmfs/userdlm.h +++ b/fs/ocfs2/dlmfs/userdlm.h @@ -66,9 +66,7 @@ void user_dlm_cluster_unlock(struct user_lock_res *lockres, void user_dlm_write_lvb(struct inode *inode, const char *val, unsigned int len); -ssize_t user_dlm_read_lvb(struct inode *inode, - char *val, - unsigned int len); +bool user_dlm_read_lvb(struct inode *inode, char *val); struct ocfs2_cluster_connection *user_dlm_register(const struct qstr *name); void user_dlm_unregister(struct ocfs2_cluster_connection *conn); void user_dlm_set_locking_protocol(void); -- cgit v1.2.3-58-ga151