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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>
114 lines
3.4 KiB
C
114 lines
3.4 KiB
C
/*
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File: linux/reiserfs_xattr.h
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*/
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#ifndef _LINUX_REISERFS_XATTR_H
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#define _LINUX_REISERFS_XATTR_H
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#include <linux/types.h>
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/* Magic value in header */
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#define REISERFS_XATTR_MAGIC 0x52465841 /* "RFXA" */
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struct reiserfs_xattr_header {
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__le32 h_magic; /* magic number for identification */
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__le32 h_hash; /* hash of the value */
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};
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#ifdef __KERNEL__
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#include <linux/init.h>
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#include <linux/list.h>
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#include <linux/rwsem.h>
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#include <linux/reiserfs_fs_i.h>
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#include <linux/reiserfs_fs.h>
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struct inode;
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struct dentry;
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struct iattr;
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struct super_block;
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struct nameidata;
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int reiserfs_xattr_register_handlers(void) __init;
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void reiserfs_xattr_unregister_handlers(void);
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int reiserfs_xattr_init(struct super_block *sb, int mount_flags);
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int reiserfs_delete_xattrs(struct inode *inode);
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int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs);
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#ifdef CONFIG_REISERFS_FS_XATTR
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#define has_xattr_dir(inode) (REISERFS_I(inode)->i_flags & i_has_xattr_dir)
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ssize_t reiserfs_getxattr(struct dentry *dentry, const char *name,
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void *buffer, size_t size);
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int reiserfs_setxattr(struct dentry *dentry, const char *name,
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const void *value, size_t size, int flags);
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ssize_t reiserfs_listxattr(struct dentry *dentry, char *buffer, size_t size);
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int reiserfs_removexattr(struct dentry *dentry, const char *name);
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int reiserfs_permission(struct inode *inode, int mask);
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int reiserfs_xattr_get(struct inode *, const char *, void *, size_t);
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int reiserfs_xattr_set(struct inode *, const char *, const void *, size_t, int);
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int reiserfs_xattr_set_handle(struct reiserfs_transaction_handle *,
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struct inode *, const char *, const void *,
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size_t, int);
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extern struct xattr_handler reiserfs_xattr_user_handler;
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extern struct xattr_handler reiserfs_xattr_trusted_handler;
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extern struct xattr_handler reiserfs_xattr_security_handler;
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#define xattr_size(size) ((size) + sizeof(struct reiserfs_xattr_header))
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static inline loff_t reiserfs_xattr_nblocks(struct inode *inode, loff_t size)
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{
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loff_t ret = 0;
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if (reiserfs_file_data_log(inode)) {
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ret = _ROUND_UP(xattr_size(size), inode->i_sb->s_blocksize);
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ret >>= inode->i_sb->s_blocksize_bits;
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}
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return ret;
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}
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/* We may have to create up to 3 objects: xattr root, xattr dir, xattr file.
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* Let's try to be smart about it.
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* xattr root: We cache it. If it's not cached, we may need to create it.
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* xattr dir: If anything has been loaded for this inode, we can set a flag
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* saying so.
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* xattr file: Since we don't cache xattrs, we can't tell. We always include
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* blocks for it.
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*
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* However, since root and dir can be created between calls - YOU MUST SAVE
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* THIS VALUE.
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*/
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static inline size_t reiserfs_xattr_jcreate_nblocks(struct inode *inode)
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{
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size_t nblocks = JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
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if ((REISERFS_I(inode)->i_flags & i_has_xattr_dir) == 0) {
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nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
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if (REISERFS_SB(inode->i_sb)->xattr_root == NULL)
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nblocks += JOURNAL_BLOCKS_PER_OBJECT(inode->i_sb);
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}
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return nblocks;
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}
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static inline void reiserfs_init_xattr_rwsem(struct inode *inode)
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{
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init_rwsem(&REISERFS_I(inode)->i_xattr_sem);
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}
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#else
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#define reiserfs_getxattr NULL
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#define reiserfs_setxattr NULL
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#define reiserfs_listxattr NULL
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#define reiserfs_removexattr NULL
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#define reiserfs_permission NULL
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static inline void reiserfs_init_xattr_rwsem(struct inode *inode)
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{
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}
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#endif /* CONFIG_REISERFS_FS_XATTR */
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#endif /* __KERNEL__ */
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#endif /* _LINUX_REISERFS_XATTR_H */
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