From 32f1a95d505b99b1f01b6aeea36ec3f97245b357 Mon Sep 17 00:00:00 2001 From: "Artem B. Bityuckiy" Date: Tue, 1 Mar 2005 10:50:52 +0000 Subject: [PATCH] [JFFS2] Add symlink caching support. Signed-off-by: Artem B. Bityuckiy Signed-off-by: Thomas Gleixner --- fs/jffs2/dir.c | 28 +++++++++++++++++------ fs/jffs2/read.c | 32 +------------------------- fs/jffs2/readinode.c | 54 +++++++++++++++++++++++++++++++++++++++----- fs/jffs2/symlink.c | 42 ++++++++++++++++++++++++---------- fs/jffs2/write.c | 31 +++++++++++++------------ 5 files changed, 117 insertions(+), 70 deletions(-) diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c index 757306fa3ff4..6421be874ce3 100644 --- a/fs/jffs2/dir.c +++ b/fs/jffs2/dir.c @@ -7,7 +7,7 @@ * * For licensing information, see the file 'LICENCE' in this directory. * - * $Id: dir.c,v 1.84 2004/11/16 20:36:11 dwmw2 Exp $ + * $Id: dir.c,v 1.85 2005/03/01 10:34:03 dedekind Exp $ * */ @@ -296,11 +296,11 @@ static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char struct jffs2_full_dirent *fd; int namelen; uint32_t alloclen, phys_ofs; - int ret; + int ret, targetlen = strlen(target); /* FIXME: If you care. We'd need to use frags for the target if it grows much more than this */ - if (strlen(target) > 254) + if (targetlen > 254) return -EINVAL; ri = jffs2_alloc_raw_inode(); @@ -314,7 +314,7 @@ static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char * Just the node will do for now, though */ namelen = dentry->d_name.len; - ret = jffs2_reserve_space(c, sizeof(*ri) + strlen(target), &phys_ofs, &alloclen, ALLOC_NORMAL); + ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &phys_ofs, &alloclen, ALLOC_NORMAL); if (ret) { jffs2_free_raw_inode(ri); @@ -333,16 +333,16 @@ static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char f = JFFS2_INODE_INFO(inode); - inode->i_size = strlen(target); + inode->i_size = targetlen; ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size); ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size); ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4)); ri->compr = JFFS2_COMPR_NONE; - ri->data_crc = cpu_to_je32(crc32(0, target, strlen(target))); + ri->data_crc = cpu_to_je32(crc32(0, target, targetlen)); ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8)); - fn = jffs2_write_dnode(c, f, ri, target, strlen(target), phys_ofs, ALLOC_NORMAL); + fn = jffs2_write_dnode(c, f, ri, target, targetlen, phys_ofs, ALLOC_NORMAL); jffs2_free_raw_inode(ri); @@ -353,6 +353,20 @@ static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char jffs2_clear_inode(inode); return PTR_ERR(fn); } + + /* We use f->dents field to store the target path. */ + f->dents = kmalloc(targetlen + 1, GFP_KERNEL); + if (!f->dents) { + printk(KERN_WARNING "Can't allocate %d bytes of memory\n", targetlen + 1); + up(&f->sem); + jffs2_complete_reservation(c); + jffs2_clear_inode(inode); + return -ENOMEM; + } + + memcpy(f->dents, target, targetlen + 1); + D1(printk(KERN_DEBUG "jffs2_symlink: symlink's target '%s' cached\n", (char *)f->dents)); + /* No data here. Only a metadata node, which will be obsoleted by the first data write */ diff --git a/fs/jffs2/read.c b/fs/jffs2/read.c index eb493dc06db7..c7f9068907cf 100644 --- a/fs/jffs2/read.c +++ b/fs/jffs2/read.c @@ -7,7 +7,7 @@ * * For licensing information, see the file 'LICENCE' in this directory. * - * $Id: read.c,v 1.38 2004/11/16 20:36:12 dwmw2 Exp $ + * $Id: read.c,v 1.39 2005/03/01 10:34:03 dedekind Exp $ * */ @@ -214,33 +214,3 @@ int jffs2_read_inode_range(struct jffs2_sb_info *c, struct jffs2_inode_info *f, return 0; } -/* Core function to read symlink target. */ -char *jffs2_getlink(struct jffs2_sb_info *c, struct jffs2_inode_info *f) -{ - char *buf; - int ret; - - down(&f->sem); - - if (!f->metadata) { - printk(KERN_NOTICE "No metadata for symlink inode #%u\n", f->inocache->ino); - up(&f->sem); - return ERR_PTR(-EINVAL); - } - buf = kmalloc(f->metadata->size+1, GFP_USER); - if (!buf) { - up(&f->sem); - return ERR_PTR(-ENOMEM); - } - buf[f->metadata->size]=0; - - ret = jffs2_read_dnode(c, f, f->metadata, buf, 0, f->metadata->size); - - up(&f->sem); - - if (ret) { - kfree(buf); - return ERR_PTR(ret); - } - return buf; -} diff --git a/fs/jffs2/readinode.c b/fs/jffs2/readinode.c index a1980a9da531..ef552477c813 100644 --- a/fs/jffs2/readinode.c +++ b/fs/jffs2/readinode.c @@ -7,7 +7,7 @@ * * For licensing information, see the file 'LICENCE' in this directory. * - * $Id: readinode.c,v 1.118 2005/02/27 23:01:33 dwmw2 Exp $ + * $Id: readinode.c,v 1.119 2005/03/01 10:34:03 dedekind Exp $ * */ @@ -623,6 +623,40 @@ static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c, case. */ if (!je32_to_cpu(latest_node->isize)) latest_node->isize = latest_node->dsize; + + if (f->inocache->state != INO_STATE_CHECKING) { + /* Symlink's inode data is the target path. Read it and + * keep in RAM to facilitate quick follow symlink operation. + * We use f->dents field to store the target path, which + * is somewhat ugly. */ + f->dents = kmalloc(je32_to_cpu(latest_node->csize) + 1, GFP_KERNEL); + if (!f->dents) { + printk(KERN_WARNING "Can't allocate %d bytes of memory " + "for the symlink target path cache\n", + je32_to_cpu(latest_node->csize)); + up(&f->sem); + jffs2_do_clear_inode(c, f); + return -ENOMEM; + } + + ret = jffs2_flash_read(c, ref_offset(fn->raw) + sizeof(*latest_node), + je32_to_cpu(latest_node->csize), &retlen, (char *)f->dents); + + if (ret || retlen != je32_to_cpu(latest_node->csize)) { + if (retlen != je32_to_cpu(latest_node->csize)) + ret = -EIO; + kfree(f->dents); + f->dents = NULL; + up(&f->sem); + jffs2_do_clear_inode(c, f); + return -ret; + } + + ((char *)f->dents)[je32_to_cpu(latest_node->csize)] = '\0'; + D1(printk(KERN_DEBUG "jffs2_do_read_inode(): symlink's target '%s' cached\n", + (char *)f->dents)); + } + /* fall through... */ case S_IFBLK: @@ -683,12 +717,20 @@ void jffs2_do_clear_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f) jffs2_kill_fragtree(&f->fragtree, deleted?c:NULL); - fds = f->dents; + /* For symlink inodes we us f->dents to store the target path name */ + if (S_ISLNK(OFNI_EDONI_2SFFJ(f)->i_mode)) { + if (f->dents) { + kfree(f->dents); + f->dents = NULL; + } + } else { + fds = f->dents; - while(fds) { - fd = fds; - fds = fd->next; - jffs2_free_full_dirent(fd); + while(fds) { + fd = fds; + fds = fd->next; + jffs2_free_full_dirent(fd); + } } if (f->inocache && f->inocache->state != INO_STATE_CHECKING) { diff --git a/fs/jffs2/symlink.c b/fs/jffs2/symlink.c index 7b1820d13712..65ab6b001dca 100644 --- a/fs/jffs2/symlink.c +++ b/fs/jffs2/symlink.c @@ -7,7 +7,7 @@ * * For licensing information, see the file 'LICENCE' in this directory. * - * $Id: symlink.c,v 1.14 2004/11/16 20:36:12 dwmw2 Exp $ + * $Id: symlink.c,v 1.16 2005/03/01 10:50:48 dedekind Exp $ * */ @@ -19,27 +19,45 @@ #include "nodelist.h" static int jffs2_follow_link(struct dentry *dentry, struct nameidata *nd); -static void jffs2_put_link(struct dentry *dentry, struct nameidata *nd); struct inode_operations jffs2_symlink_inode_operations = { .readlink = generic_readlink, .follow_link = jffs2_follow_link, - .put_link = jffs2_put_link, .setattr = jffs2_setattr }; static int jffs2_follow_link(struct dentry *dentry, struct nameidata *nd) { - unsigned char *buf; - buf = jffs2_getlink(JFFS2_SB_INFO(dentry->d_inode->i_sb), JFFS2_INODE_INFO(dentry->d_inode)); - nd_set_link(nd, buf); + struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode); + + /* + * We don't acquire the f->sem mutex here since the only data we + * use is f->dents which in case of the symlink inode points to the + * symlink's target path. + * + * 1. If we are here the inode has already built and f->dents has + * to point to the target path. + * 2. Nobody uses f->dents (if the inode is symlink's inode). The + * exception is inode freeing function which frees f->dents. But + * it can't be called while we are here and before VFS has + * stopped using our f->dents string which we provide by means of + * nd_set_link() call. + */ + + if (!f->dents) { + printk(KERN_ERR "jffs2_follow_link(): can't find symlink taerget\n"); + return -EIO; + } + D1(printk(KERN_DEBUG "jffs2_follow_link(): target path is '%s'\n", (char *) f->dents)); + + nd_set_link(nd, (char *)f->dents); + + /* + * We unlock the f->sem mutex but VFS will use the f->dents string. This is safe + * since the only way that may cause f->dents to be changed is iput() operation. + * But VFS will not use f->dents after iput() has been called. + */ return 0; } -static void jffs2_put_link(struct dentry *dentry, struct nameidata *nd) -{ - char *s = nd_get_link(nd); - if (!IS_ERR(s)) - kfree(s); -} diff --git a/fs/jffs2/write.c b/fs/jffs2/write.c index d6b4d55e70e4..f3910dc1c2c8 100644 --- a/fs/jffs2/write.c +++ b/fs/jffs2/write.c @@ -7,7 +7,7 @@ * * For licensing information, see the file 'LICENCE' in this directory. * - * $Id: write.c,v 1.90 2005/01/28 18:53:01 hammache Exp $ + * $Id: write.c,v 1.91 2005/03/01 10:34:03 dedekind Exp $ * */ @@ -644,20 +644,23 @@ int jffs2_do_unlink(struct jffs2_sb_info *c, struct jffs2_inode_info *dir_f, down(&dead_f->sem); - while (dead_f->dents) { - /* There can be only deleted ones */ - fd = dead_f->dents; - - dead_f->dents = fd->next; - - if (fd->ino) { - printk(KERN_WARNING "Deleting inode #%u with active dentry \"%s\"->ino #%u\n", - dead_f->inocache->ino, fd->name, fd->ino); - } else { - D1(printk(KERN_DEBUG "Removing deletion dirent for \"%s\" from dir ino #%u\n", fd->name, dead_f->inocache->ino)); + if (S_ISDIR(OFNI_EDONI_2SFFJ(dead_f)->i_mode)) { + while (dead_f->dents) { + /* There can be only deleted ones */ + fd = dead_f->dents; + + dead_f->dents = fd->next; + + if (fd->ino) { + printk(KERN_WARNING "Deleting inode #%u with active dentry \"%s\"->ino #%u\n", + dead_f->inocache->ino, fd->name, fd->ino); + } else { + D1(printk(KERN_DEBUG "Removing deletion dirent for \"%s\" from dir ino #%u\n", + fd->name, dead_f->inocache->ino)); + } + jffs2_mark_node_obsolete(c, fd->raw); + jffs2_free_full_dirent(fd); } - jffs2_mark_node_obsolete(c, fd->raw); - jffs2_free_full_dirent(fd); } dead_f->inocache->nlink--; -- GitLab