0ab2621ebd
Deadlocks are possible in the xattr code between the journal lock and the xattr sems. This patch implements journalling for xattr operations. The benefit is twofold: * It gets rid of the deadlock possibility by always ensuring that xattr write operations are initiated inside a transaction. * It corrects the problem where xattr backing files aren't considered any differently than normal files, despite the fact they are metadata. I discussed the added journal load with Chris Mason, and we decided that since xattrs (versus other journal activity) is fairly rare, the introduction of larger transactions to support journaled xattrs wouldn't be too big a deal. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
97 lines
2.2 KiB
C
97 lines
2.2 KiB
C
#include <linux/init.h>
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#include <linux/posix_acl.h>
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#define REISERFS_ACL_VERSION 0x0001
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typedef struct {
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__le16 e_tag;
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__le16 e_perm;
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__le32 e_id;
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} reiserfs_acl_entry;
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typedef struct {
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__le16 e_tag;
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__le16 e_perm;
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} reiserfs_acl_entry_short;
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typedef struct {
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__le32 a_version;
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} reiserfs_acl_header;
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static inline size_t reiserfs_acl_size(int count)
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{
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if (count <= 4) {
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return sizeof(reiserfs_acl_header) +
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count * sizeof(reiserfs_acl_entry_short);
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} else {
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return sizeof(reiserfs_acl_header) +
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4 * sizeof(reiserfs_acl_entry_short) +
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(count - 4) * sizeof(reiserfs_acl_entry);
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}
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}
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static inline int reiserfs_acl_count(size_t size)
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{
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ssize_t s;
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size -= sizeof(reiserfs_acl_header);
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s = size - 4 * sizeof(reiserfs_acl_entry_short);
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if (s < 0) {
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if (size % sizeof(reiserfs_acl_entry_short))
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return -1;
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return size / sizeof(reiserfs_acl_entry_short);
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} else {
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if (s % sizeof(reiserfs_acl_entry))
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return -1;
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return s / sizeof(reiserfs_acl_entry) + 4;
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}
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}
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#ifdef CONFIG_REISERFS_FS_POSIX_ACL
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struct posix_acl *reiserfs_get_acl(struct inode *inode, int type);
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int reiserfs_acl_chmod(struct inode *inode);
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int reiserfs_inherit_default_acl(struct reiserfs_transaction_handle *th,
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struct inode *dir, struct dentry *dentry,
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struct inode *inode);
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int reiserfs_cache_default_acl(struct inode *dir);
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extern struct xattr_handler reiserfs_posix_acl_default_handler;
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extern struct xattr_handler reiserfs_posix_acl_access_handler;
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static inline void reiserfs_init_acl_access(struct inode *inode)
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{
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REISERFS_I(inode)->i_acl_access = NULL;
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}
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static inline void reiserfs_init_acl_default(struct inode *inode)
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{
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REISERFS_I(inode)->i_acl_default = NULL;
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}
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#else
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#define reiserfs_cache_default_acl(inode) 0
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static inline struct posix_acl *reiserfs_get_acl(struct inode *inode, int type)
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{
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return NULL;
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}
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static inline int reiserfs_acl_chmod(struct inode *inode)
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{
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return 0;
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}
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static inline int
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reiserfs_inherit_default_acl(const struct inode *dir, struct dentry *dentry,
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struct inode *inode)
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{
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return 0;
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}
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static inline void reiserfs_init_acl_access(struct inode *inode)
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{
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}
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static inline void reiserfs_init_acl_default(struct inode *inode)
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{
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}
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#endif
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