Messages in this thread Patch in this message |  | | Subject | [Patch] symlink fix for shm/swap fs | From | Christoph Rohland <> | Date | 13 Jan 2001 17:03:46 +0100 |
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Hi Alan,
Here comes a patch which fixes the totally broken symlink support in shm/swapfs. It is additional to my former patches for read and write support.
It survives now a parallel kernel make on my 8way.
Greetings Christoph
diff -uNr 2.4.0-shm_vm_locked-truncate-rw-swapfs/mm/shmem.c 2.4.0-shm_vm_locked-truncate-rw-swapfs-symlink/mm/shmem.c --- 2.4.0-shm_vm_locked-truncate-rw-swapfs/mm/shmem.c Sat Jan 13 13:22:59 2001 +++ 2.4.0-shm_vm_locked-truncate-rw-swapfs-symlink/mm/shmem.c Sat Jan 13 16:29:53 2001 @@ -39,6 +39,7 @@ static struct inode_operations shmem_inode_operations; static struct file_operations shmem_dir_operations; static struct inode_operations shmem_dir_inode_operations; +static struct inode_operations shmem_symlink_inode_operations; static struct vm_operations_struct shmem_vm_ops; LIST_HEAD (shmem_inodes); @@ -127,7 +128,7 @@ spin_lock (&info->lock); index = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; - if (index >= info->max_index) + if (index > info->max_index) goto out; start = shmem_truncate_part (info->i_direct, SHMEM_NR_DIRECT, index, &freed); @@ -419,7 +420,7 @@ inode->i_fop = &shmem_dir_operations; break; case S_IFLNK: - inode->i_op = &page_symlink_inode_operations; + inode->i_op = &shmem_symlink_inode_operations; break; } spin_lock (&shmem_ilock); @@ -787,14 +788,63 @@ static int shmem_symlink(struct inode * dir, struct dentry *dentry, const char * symname) { int error; + int len; + struct inode *inode; + struct page *page; + char *kaddr; error = shmem_mknod(dir, dentry, S_IFLNK | S_IRWXUGO, 0); - if (!error) { - int l = strlen(symname)+1; - struct inode *inode = dentry->d_inode; - error = block_symlink(inode, symname, l); - } - return error; + if (error) + return error; + + len = strlen(symname); + if (len > PAGE_SIZE) + return -ENAMETOOLONG; + + inode = dentry->d_inode; + down(&inode->i_sem); + page = shmem_getpage_locked(inode, 0); + if (IS_ERR(page)) + goto fail; + kaddr = kmap(page); + memcpy(kaddr, symname, len); + kunmap(page); + inode->i_size = len; + SetPageDirty(page); + UnlockPage(page); + page_cache_release(page); + up(&inode->i_sem); + return 0; +fail: + up(&inode->i_sem); + return PTR_ERR(page); +} + +static int shmem_readlink(struct dentry *dentry, char *buffer, int buflen) +{ + struct page * page; + int res = shmem_getpage(dentry->d_inode, 0, &page); + + if (res) + return res; + + res = vfs_readlink(dentry,buffer,buflen, kmap(page)); + kunmap(page); + page_cache_release(page); + return res; +} + +static int shmem_follow_link(struct dentry *dentry, struct nameidata *nd) +{ + struct page * page; + int res = shmem_getpage(dentry->d_inode, 0, &page); + if (res) + return res; + + res = vfs_follow_link(nd, kmap(page)); + kunmap(page); + page_cache_release(page); + return res; } static int shmem_parse_options(char *options, int *mode, unsigned long * blocks, unsigned long *inodes) @@ -912,6 +962,12 @@ static struct inode_operations shmem_inode_operations = { truncate: shmem_truncate, +}; + +static struct inode_operations shmem_symlink_inode_operations = { + truncate: shmem_truncate, + readlink: shmem_readlink, + follow_link: shmem_follow_link, }; static struct file_operations shmem_dir_operations = { - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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