/* * fs/isofs/export.c * * (C) 2004 Paul Serice - The new inode scheme requires switching * from iget() to iget5_locked() which means * the NFS export operations have to be hand * coded because the default routines rely on * iget(). * * The following files are helpful: * * Documentation/filesystems/nfs/Exporting * fs/exportfs/expfs.c. */ #include "isofs.h" static struct dentry * isofs_export_iget(struct super_block *sb, unsigned long block, unsigned long offset, __u32 generation) { struct inode *inode; if (block == 0) return ERR_PTR(-ESTALE); inode = isofs_iget(sb, block, offset); if (IS_ERR(inode)) return ERR_CAST(inode); if (generation && inode->i_generation != generation) { iput(inode); return ERR_PTR(-ESTALE); } return d_obtain_alias(inode); } /* This function is surprisingly simple. The trick is understanding * that "child" is always a directory. So, to find its parent, you * simply need to find its ".." entry, normalize its block and offset, * and return the underlying inode. See the comments for * isofs_normalize_block_and_offset(). */ static struct dentry *isofs_export_get_parent(struct dentry *child) { unsigned long parent_block = 0; unsigned long parent_offset = 0; struct inode *child_inode = d_inode(child); struct iso_inode_info *e_child_inode = ISOFS_I(child_inode); struct iso_directory_record *de = NULL; struct buffer_head * bh = NULL; struct dentry *rv = NULL; /* "child" must always be a directory. */ if (!S_ISDIR(child_inode->i_mode)) { printk(KERN_ERR "isofs: isofs_export_get_parent(): " "child is not a directory!\n"); rv = ERR_PTR(-EACCES); goto out; } /* It is an invariant that the directory offset is zero. If * it is not zero, it means the directory failed to be * normalized for some reason. */ if (e_child_inode->i_iget5_offset != 0) { printk(KERN_ERR "isofs: isofs_export_get_parent(): " "child directory not normalized!\n"); rv = ERR_PTR(-EACCES); goto out; } /* The child inode has been normalized such that its * i_iget5_block value points to the "." entry. Fortunately, * the ".." entry is located in the same block. */ parent_block = e_child_inode->i_iget5_block; /* Get the block in question. */ bh = sb_bread(child_inode->i_sb, parent_block); if (bh == NULL) { rv = ERR_PTR(-EACCES); goto out; } /* This is the "." entry. */ de = (struct iso_directory_record*)bh->b_data; /* The ".." entry is always the second entry. */ parent_offset = (unsigned long)isonum_711(de->length); de = (struct iso_directory_record*)(bh->b_data + parent_offset); /* Verify it is in fact the ".." entry. */ if ((isonum_711(de->name_len) != 1) || (de->name[0] != 1)) { printk(KERN_ERR "isofs: Unable to find the \"..\" " "directory for NFS.\n"); rv = ERR_PTR(-EACCES); goto out; } /* Normalize */ isofs_normalize_block_and_offset(de, &parent_block, &parent_offset); rv = d_obtain_alias(isofs_iget(child_inode->i_sb, parent_block, parent_offset)); out: if (bh) brelse(bh); return rv; } static int isofs_export_encode_fh(struct inode *inode, __u32 *fh32, int *max_len, struct inode *parent) { struct iso_inode_info * ei = ISOFS_I(inode); int len = *max_len; int type = 1; __u16 *fh16 = (__u16*)fh32; /* * WARNING: max_len is 5 for NFSv2. Because of this * limitation, we use the lower 16 bits of fh32[1] to hold the * offset of the inode and the upper 16 bits of fh32[1] to * hold the offset of the parent. */ if (parent && (len < 5)) { *max_len = 5; return FILEID_INVALID; } else if (len < 3) { *max_len = 3; return FILEID_INVALID; } len = 3; fh32[0] = ei->i_iget5_block; fh16[2] = (__u16)ei->i_iget5_offset; /* fh16 [sic] */ fh16[3] = 0; /* avoid leaking uninitialized data */ fh32[2] = inode->i_generation; if (parent) { struct iso_inode_info *eparent; eparent = ISOFS_I(parent); fh32[3] = eparent->i_iget5_block; fh16[3] = (__u16)eparent->i_iget5_offset; /* fh16 [sic] */ fh32[4] = parent->i_generation; len = 5; type = 2; } *max_len = len; return type; } struct isofs_fid { u32 block; u16 offset; u16 parent_offset; u32 generation; u32 parent_block; u32 parent_generation; }; static struct dentry *isofs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { struct isofs_fid *ifid = (struct isofs_fid *)fid; if (fh_len < 3 || fh_type > 2) return NULL; return isofs_export_iget(sb, ifid->block, ifid->offset, ifid->generation); } static struct dentry *isofs_fh_to_parent(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { struct isofs_fid *ifid = (struct isofs_fid *)fid; if (fh_len < 2 || fh_type != 2) return NULL; return isofs_export_iget(sb, fh_len > 2 ? ifid->parent_block : 0, ifid->parent_offset, fh_len > 4 ? ifid->parent_generation : 0); } const struct export_operations isofs_export_ops = { .encode_fh = isofs_export_encode_fh, .fh_to_dentry = isofs_fh_to_dentry, .fh_to_parent = isofs_fh_to_parent, .get_parent = isofs_export_get_parent, }; Steven Rostedt (VMware) <rostedt@goodmis.org>2017-01-31 09:13:49 -0500 commit79c6f448c8b79c321e4a1f31f98194e4f6b6cae7 (patch) tree370efda701f03cccf21e02bb1fdd3b852547d75c /include/soc/tegra/fuse.h parent0c744ea4f77d72b3dcebb7a8f2684633ec79be88 (diff)
tracing: Fix hwlat kthread migration
The hwlat tracer creates a kernel thread at start of the tracer. It is pinned to a single CPU and will move to the next CPU after each period of running. If the user modifies the migration thread's affinity, it will not change after that happens. The original code created the thread at the first instance it was called, but later was changed to destroy the thread after the tracer was finished, and would not be created until the next instance of the tracer was established. The code that initialized the affinity was only called on the initial instantiation of the tracer. After that, it was not initialized, and the previous affinity did not match the current newly created one, making it appear that the user modified the thread's affinity when it did not, and the thread failed to migrate again. Cc: stable@vger.kernel.org Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'include/soc/tegra/fuse.h')