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Add new helper - simplefs_inode_save()

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And use it next functions:
- simplefs_write()
- simplefs_create_fs_object()
This commit is contained in:
Azat Khuzhin 2013-09-29 18:59:30 +04:00
parent 2d95ccf1a3
commit 86d7a8ff80
1 changed files with 44 additions and 55 deletions
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99
simple.c
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@ -304,6 +304,43 @@ ssize_t simplefs_read(struct file * filp, char __user * buf, size_t len,
return nbytes;
}
/* Save the modified inode */
int simplefs_inode_save(struct super_block *sb, struct simplefs_inode *sfs_inode)
{
struct simplefs_inode *inode_iterator;
struct buffer_head *bh;
bh = sb_bread(sb, SIMPLEFS_INODESTORE_BLOCK_NUMBER);
if (mutex_lock_interruptible(&simplefs_sb_lock)) {
sfs_trace("Failed to acquire mutex lock\n");
return -EINTR;
}
inode_iterator = simplefs_inode_search(sb,
(struct simplefs_inode *)bh->b_data,
sfs_inode);
if (likely(inode_iterator)) {
memcpy(inode_iterator, sfs_inode, sizeof(*inode_iterator));
printk(KERN_INFO "The inode updated\n");
mark_buffer_dirty(bh);
sync_dirty_buffer(bh);
} else {
mutex_unlock(&simplefs_sb_lock);
printk(KERN_ERR
"The new filesize could not be stored to the inode.");
return -EIO;
}
brelse(bh);
mutex_unlock(&simplefs_sb_lock);
return 0;
}
/* FIXME: The write support is rudimentary. I have not figured out a way to do writes
* from particular offsets (even though I have written some untested code for this below) efficiently. */
ssize_t simplefs_write(struct file * filp, const char __user * buf, size_t len,
@ -314,7 +351,6 @@ ssize_t simplefs_write(struct file * filp, const char __user * buf, size_t len,
* f->f_path.dentry->d_inode redirection */
struct inode *inode;
struct simplefs_inode *sfs_inode;
struct simplefs_inode *inode_iterator;
struct buffer_head *bh;
struct super_block *sb;
@ -367,37 +403,11 @@ ssize_t simplefs_write(struct file * filp, const char __user * buf, size_t len,
sfs_trace("Failed to acquire mutex lock\n");
return -EINTR;
}
/* Save the modified inode */
bh = sb_bread(sb, SIMPLEFS_INODESTORE_BLOCK_NUMBER);
sfs_inode->file_size = *ppos;
if (mutex_lock_interruptible(&simplefs_sb_lock)) {
sfs_trace("Failed to acquire mutex lock\n");
return -EINTR;
retval = simplefs_inode_save(sb, sfs_inode);
if (retval) {
len = retval;
}
inode_iterator = simplefs_inode_search(sb,
(struct simplefs_inode *)bh->b_data,
sfs_inode);
if (likely(inode_iterator)) {
inode_iterator->file_size = sfs_inode->file_size;
printk(KERN_INFO
"The new filesize that is written is: [%llu] and len was: [%lu]\n",
sfs_inode->file_size, len);
mark_buffer_dirty(bh);
sync_dirty_buffer(bh);
} else {
printk(KERN_ERR
"The new filesize could not be stored to the inode.");
len = -EIO;
}
brelse(bh);
mutex_unlock(&simplefs_sb_lock);
mutex_unlock(&simplefs_inodes_mgmt_lock);
return len;
@ -437,7 +447,6 @@ static int simplefs_create_fs_object(struct inode *dir, struct dentry *dentry,
{
struct inode *inode;
struct simplefs_inode *sfs_inode;
struct simplefs_inode *inode_iterator;
struct super_block *sb;
struct simplefs_inode *parent_dir_inode;
struct buffer_head *bh;
@ -541,38 +550,18 @@ static int simplefs_create_fs_object(struct inode *dir, struct dentry *dentry,
return -EINTR;
}
bh = sb_bread(sb, SIMPLEFS_INODESTORE_BLOCK_NUMBER);
if (mutex_lock_interruptible(&simplefs_sb_lock)) {
parent_dir_inode->dir_children_count++;
ret = simplefs_inode_save(sb, parent_dir_inode);
if (ret) {
mutex_unlock(&simplefs_inodes_mgmt_lock);
mutex_unlock(&simplefs_directory_children_update_lock);
sfs_trace("Failed to acquire mutex lock\n");
return -EINTR;
}
inode_iterator = simplefs_inode_search(sb,
(struct simplefs_inode *)bh->b_data,
parent_dir_inode);
if (inode_iterator) {
parent_dir_inode->dir_children_count++;
inode_iterator->dir_children_count =
parent_dir_inode->dir_children_count;
/* Updated the parent inode's dir count to reflect the new child too */
mark_buffer_dirty(bh);
sync_dirty_buffer(bh);
} else {
printk(KERN_ERR
"The updated childcount could not be stored to the dir inode.");
/* TODO: Remove the newly created inode from the disk and in-memory inode store
* and also update the superblock, freemaps etc. to reflect the same.
* Basically, Undo all actions done during this create call */
return ret;
}
brelse(bh);
mutex_unlock(&simplefs_sb_lock);
mutex_unlock(&simplefs_inodes_mgmt_lock);
mutex_unlock(&simplefs_directory_children_update_lock);