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author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-02-13 06:43:25 (GMT) |
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committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2007-02-13 06:43:25 (GMT) |
commit | d9bc125caf592b7d081021f32ce5b717efdf70c8 (patch) | |
tree | 263b7066ba22ddce21db610c0300f6eaac6f2064 /fs/sysfs/file.c | |
parent | 43d78ef2ba5bec26d0315859e8324bfc0be23766 (diff) | |
parent | ec2f9d1331f658433411c58077871e1eef4ee1b4 (diff) | |
download | linux-d9bc125caf592b7d081021f32ce5b717efdf70c8.tar.xz |
Merge branch 'master' of /home/trondmy/kernel/linux-2.6/
Conflicts:
net/sunrpc/auth_gss/gss_krb5_crypto.c
net/sunrpc/auth_gss/gss_spkm3_token.c
net/sunrpc/clnt.c
Merge with mainline and fix conflicts.
Diffstat (limited to 'fs/sysfs/file.c')
-rw-r--r-- | fs/sysfs/file.c | 82 |
1 files changed, 58 insertions, 24 deletions
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 9cfe53e..c0e1176 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -7,6 +7,7 @@ #include <linux/kobject.h> #include <linux/namei.h> #include <linux/poll.h> +#include <linux/list.h> #include <asm/uaccess.h> #include <asm/semaphore.h> @@ -50,17 +51,29 @@ static struct sysfs_ops subsys_sysfs_ops = { .store = subsys_attr_store, }; +/** + * add_to_collection - add buffer to a collection + * @buffer: buffer to be added + * @node inode of set to add to + */ -struct sysfs_buffer { - size_t count; - loff_t pos; - char * page; - struct sysfs_ops * ops; - struct semaphore sem; - int needs_read_fill; - int event; -}; +static inline void +add_to_collection(struct sysfs_buffer *buffer, struct inode *node) +{ + struct sysfs_buffer_collection *set = node->i_private; + mutex_lock(&node->i_mutex); + list_add(&buffer->associates, &set->associates); + mutex_unlock(&node->i_mutex); +} + +static inline void +remove_from_collection(struct sysfs_buffer *buffer, struct inode *node) +{ + mutex_lock(&node->i_mutex); + list_del(&buffer->associates); + mutex_unlock(&node->i_mutex); +} /** * fill_read_buffer - allocate and fill buffer from object. @@ -70,7 +83,8 @@ struct sysfs_buffer { * Allocate @buffer->page, if it hasn't been already, then call the * kobject's show() method to fill the buffer with this attribute's * data. - * This is called only once, on the file's first read. + * This is called only once, on the file's first read unless an error + * is returned. */ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer) { @@ -88,12 +102,13 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer buffer->event = atomic_read(&sd->s_event); count = ops->show(kobj,attr,buffer->page); - buffer->needs_read_fill = 0; BUG_ON(count > (ssize_t)PAGE_SIZE); - if (count >= 0) + if (count >= 0) { + buffer->needs_read_fill = 0; buffer->count = count; - else + } else { ret = count; + } return ret; } @@ -153,6 +168,10 @@ sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos) ssize_t retval = 0; down(&buffer->sem); + if (buffer->orphaned) { + retval = -ENODEV; + goto out; + } if (buffer->needs_read_fill) { if ((retval = fill_read_buffer(file->f_path.dentry,buffer))) goto out; @@ -165,7 +184,6 @@ out: return retval; } - /** * fill_write_buffer - copy buffer from userspace. * @buffer: data buffer for file. @@ -243,19 +261,25 @@ sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t ssize_t len; down(&buffer->sem); + if (buffer->orphaned) { + len = -ENODEV; + goto out; + } len = fill_write_buffer(buffer, buf, count); if (len > 0) len = flush_write_buffer(file->f_path.dentry, buffer, len); if (len > 0) *ppos += len; +out: up(&buffer->sem); return len; } -static int check_perm(struct inode * inode, struct file * file) +static int sysfs_open_file(struct inode *inode, struct file *file) { struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent); struct attribute * attr = to_attr(file->f_path.dentry); + struct sysfs_buffer_collection *set; struct sysfs_buffer * buffer; struct sysfs_ops * ops = NULL; int error = 0; @@ -285,6 +309,18 @@ static int check_perm(struct inode * inode, struct file * file) if (!ops) goto Eaccess; + /* make sure we have a collection to add our buffers to */ + mutex_lock(&inode->i_mutex); + if (!(set = inode->i_private)) { + if (!(set = inode->i_private = kmalloc(sizeof(struct sysfs_buffer_collection), GFP_KERNEL))) { + error = -ENOMEM; + goto Done; + } else { + INIT_LIST_HEAD(&set->associates); + } + } + mutex_unlock(&inode->i_mutex); + /* File needs write support. * The inode's perms must say it's ok, * and we must have a store method. @@ -310,9 +346,11 @@ static int check_perm(struct inode * inode, struct file * file) */ buffer = kzalloc(sizeof(struct sysfs_buffer), GFP_KERNEL); if (buffer) { + INIT_LIST_HEAD(&buffer->associates); init_MUTEX(&buffer->sem); buffer->needs_read_fill = 1; buffer->ops = ops; + add_to_collection(buffer, inode); file->private_data = buffer; } else error = -ENOMEM; @@ -325,16 +363,11 @@ static int check_perm(struct inode * inode, struct file * file) error = -EACCES; module_put(attr->owner); Done: - if (error && kobj) + if (error) kobject_put(kobj); return error; } -static int sysfs_open_file(struct inode * inode, struct file * filp) -{ - return check_perm(inode,filp); -} - static int sysfs_release(struct inode * inode, struct file * filp) { struct kobject * kobj = to_kobj(filp->f_path.dentry->d_parent); @@ -342,8 +375,9 @@ static int sysfs_release(struct inode * inode, struct file * filp) struct module * owner = attr->owner; struct sysfs_buffer * buffer = filp->private_data; - if (kobj) - kobject_put(kobj); + if (buffer) + remove_from_collection(buffer, inode); + kobject_put(kobj); /* After this point, attr should not be accessed. */ module_put(owner); @@ -548,7 +582,7 @@ EXPORT_SYMBOL_GPL(sysfs_chmod_file); void sysfs_remove_file(struct kobject * kobj, const struct attribute * attr) { - sysfs_hash_and_remove(kobj->dentry,attr->name); + sysfs_hash_and_remove(kobj->dentry, attr->name); } |