/* * Cache operations for Coda. * For Linux 2.1: (C) 1997 Carnegie Mellon University * For Linux 2.3: (C) 2000 Carnegie Mellon University * * Carnegie Mellon encourages users of this code to contribute improvements * to the Coda project http://www.coda.cs.cmu.edu/ . */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "coda_linux.h" #include "coda_cache.h" static atomic_t permission_epoch = ATOMIC_INIT(0); /* replace or extend an acl cache hit */ void coda_cache_enter(struct inode *inode, int mask) { struct coda_inode_info *cii = ITOC(inode); spin_lock(&cii->c_lock); cii->c_cached_epoch = atomic_read(&permission_epoch); if (!uid_eq(cii->c_uid, current_fsuid())) { cii->c_uid = current_fsuid(); cii->c_cached_perm = mask; } else cii->c_cached_perm |= mask; spin_unlock(&cii->c_lock); } /* remove cached acl from an inode */ void coda_cache_clear_inode(struct inode *inode) { struct coda_inode_info *cii = ITOC(inode); spin_lock(&cii->c_lock); cii->c_cached_epoch = atomic_read(&permission_epoch) - 1; spin_unlock(&cii->c_lock); } /* remove all acl caches */ void coda_cache_clear_all(struct super_block *sb) { atomic_inc(&permission_epoch); } /* check if the mask has been matched against the acl already */ int coda_cache_check(struct inode *inode, int mask) { struct coda_inode_info *cii = ITOC(inode); int hit; spin_lock(&cii->c_lock); hit = (mask & cii->c_cached_perm) == mask && uid_eq(cii->c_uid, current_fsuid()) && cii->c_cached_epoch == atomic_read(&permission_epoch); spin_unlock(&cii->c_lock); return hit; } /* Purging dentries and children */ /* The following routines drop dentries which are not in use and flag dentries which are in use to be zapped later. The flags are detected by: - coda_dentry_revalidate (for lookups) if the flag is C_PURGE - coda_dentry_delete: to remove dentry from the cache when d_count falls to zero - an inode method coda_revalidate (for attributes) if the flag is C_VATTR */ /* this won't do any harm: just flag all children */ static void coda_flag_children(struct dentry *parent, int flag) { struct dentry *de; spin_lock(&parent->d_lock); list_for_each_entry(de, &parent->d_subdirs, d_child) { /* don't know what to do with negative dentries */ if (d_inode(de) ) coda_flag_inode(d_inode(de), flag); } spin_unlock(&parent->d_lock); return; } void coda_flag_inode_children(struct inode *inode, int flag) { struct dentry *alias_de; if ( !inode || !S_ISDIR(inode->i_mode)) return; alias_de = d_find_alias(inode); if (!alias_de) return; coda_flag_children(alias_de, flag); shrink_dcache_parent(alias_de); dput(alias_de); } ef='/cgit.cgi/linux/net-next.git/commit/tools?h=nds-private-remove&id=f598f82e204ec0b17797caaf1b0311c52d43fb9a'>tools/build/tests
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authorColy Li <colyli@suse.de>2017-01-24 15:18:46 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-24 16:26:14 -0800
commitf598f82e204ec0b17797caaf1b0311c52d43fb9a (patch)
tree20e0109db50c168a36df14af76b484eaf9b71836 /tools/build/tests
parent4180c4c170a5a33b9987b314d248a9d572d89ab0 (diff)
romfs: use different way to generate fsid for BLOCK or MTD
Commit 8a59f5d25265 ("fs/romfs: return f_fsid for statfs(2)") generates a 64bit id from sb->s_bdev->bd_dev. This is only correct when romfs is defined with CONFIG_ROMFS_ON_BLOCK. If romfs is only defined with CONFIG_ROMFS_ON_MTD, sb->s_bdev is NULL, referencing sb->s_bdev->bd_dev will triger an oops. Richard Weinberger points out that when CONFIG_ROMFS_BACKED_BY_BOTH=y, both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD are defined. Therefore when calling huge_encode_dev() to generate a 64bit id, I use the follow order to choose parameter, - CONFIG_ROMFS_ON_BLOCK defined use sb->s_bdev->bd_dev - CONFIG_ROMFS_ON_BLOCK undefined and CONFIG_ROMFS_ON_MTD defined use sb->s_dev when, - both CONFIG_ROMFS_ON_BLOCK and CONFIG_ROMFS_ON_MTD undefined leave id as 0 When CONFIG_ROMFS_ON_MTD is defined and sb->s_mtd is not NULL, sb->s_dev is set to a device ID generated by MTD_BLOCK_MAJOR and mtd index, otherwise sb->s_dev is 0. This is a try-best effort to generate a uniq file system ID, if all the above conditions are not meet, f_fsid of this romfs instance will be 0. Generally only one romfs can be built on single MTD block device, this method is enough to identify multiple romfs instances in a computer. Link: http://lkml.kernel.org/r/1482928596-115155-1-git-send-email-colyli@suse.de Signed-off-by: Coly Li <colyli@suse.de> Reported-by: Nong Li <nongli1031@gmail.com> Tested-by: Nong Li <nongli1031@gmail.com> Cc: Richard Weinberger <richard.weinberger@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools/build/tests')