/* * fs/logfs/dir.c - directory-related code * * As should be obvious for Linux kernel code, license is GPLv2 * * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org> */#include "logfs.h"#include <linux/slab.h> /* * Atomic dir operations * * Directory operations are by default not atomic. Dentries and Inodes are * created/removed/altered in separate operations. Therefore we need to do * a small amount of journaling. * * Create, link, mkdir, mknod and symlink all share the same function to do * the work: __logfs_create. This function works in two atomic steps: * 1. allocate inode (remember in journal) * 2. allocate dentry (clear journal) * * As we can only get interrupted between the two, when the inode we just * created is simply stored in the anchor. On next mount, if we were * interrupted, we delete the inode. From a users point of view the * operation never happened. * * Unlink and rmdir also share the same function: unlink. Again, this * function works in two atomic steps * 1. remove dentry (remember inode in journal) * 2. unlink inode (clear journal) * * And again, on the next mount, if we were interrupted, we delete the inode. * From a users point of view the operation succeeded. * * Rename is the real pain to deal with, harder than all the other methods * combined. Depending on the circumstances we can run into three cases. * A "target rename" where the target dentry already existed, a "local * rename" where both parent directories are identical or a "cross-directory * rename" in the remaining case. * * Local rename is atomic, as the old dentry is simply rewritten with a new * name. * * Cross-directory rename works in two steps, similar to __logfs_create and * logfs_unlink: * 1. Write new dentry (remember old dentry in journal) * 2. Remove old dentry (clear journal) * * Here we remember a dentry instead of an inode. On next mount, if we were * interrupted, we delete the dentry. From a users point of view, the * operation succeeded. * * Target rename works in three atomic steps: * 1. Attach old inode to new dentry (remember old dentry and new inode) * 2. Remove old dentry (still remember the new inode) * 3. Remove victim inode * * Here we remember both an inode an a dentry. If we get interrupted * between steps 1 and 2, we delete both the dentry and the inode. If * we get interrupted between steps 2 and 3, we delete just the inode. * In either case, the remaining objects are deleted on next mount. From * a users point of view, the operation succeeded. */ static int write_dir(struct inode *dir, struct logfs_disk_dentry *dd, loff_t pos){ return logfs_inode_write(dir, dd, sizeof(*dd), pos, WF_LOCK, NULL);} static int write_inode(struct inode *inode){ return __logfs_write_inode(inode, NULL, WF_LOCK);} static s64 dir_seek_data(struct inode *inode, s64 pos){ s64 new_pos = logfs_seek_data(inode, pos); return max(pos, new_pos - 1);} static int beyond_eof(struct inode *inode, loff_t bix){ loff_t pos = bix << inode->i_sb->s_blocksize_bits; return pos >= i_size_read(inode);} /* * Prime value was chosen to be roughly 256 + 26. r5 hash uses 11, * so short names (len <= 9) don't even occupy the complete 32bit name * space. A prime >256 ensures short names quickly spread the 32bit * name space. Add about 26 for the estimated amount of information * of each character and pick a prime nearby, preferably a bit-sparse * one. */static u32 hash_32(const char *s, int len, u32 seed){ u32 hash = seed; int i; for (i = 0; i < len; i++) hash = hash * 293 + s[i]; return hash;} /* * We have to satisfy several conflicting requirements here. Small * directories should stay fairly compact and not require too many * indirect blocks. The number of possible locations for a given hash * should be small to make lookup() fast. And we should try hard not * to overflow the 32bit name space or nfs and 32bit host systems will * be unhappy. * * So we use the following scheme. First we reduce the hash to 0..15 * and try a direct block. If that is occupied we reduce the hash to * 16..255 and try an indirect block. Same for 2x and 3x indirect * blocks. Lastly we reduce the hash to 0x800_0000 .. 0xffff_ffff, * but use buckets containing eight entries instead of a single one. * * Using 16 entries should allow for a reasonable amount of hash * collisions, so the 32bit name space can be packed fairly tight * before overflowing. Oh and currently we don't overflow but return * and error. * * How likely are collisions? Doing the appropriate math is beyond me * and the Bronstein textbook. But running a test program to brute * force collisions for a couple of days showed that on average the * first collision occurs after 598M entries, with 290M being the * smallest result. Obviously 21 entries could already cause a * collision if all entries are carefully chosen. */static pgoff_t hash_index(u32 hash, int round){ u32 i0_blocks = I0_BLOCKS; u32 i1_blocks = I1_BLOCKS; u32 i2_blocks = I2_BLOCKS; u32 i3_blocks = I3_BLOCKS; switch (round) { case 0: return hash % i0_blocks; case 1: return i0_blocks + hash % (i1_blocks - i0_blocks); case 2: return i1_blocks + hash % (i2_blocks - i1_blocks); case 3: return i2_blocks + hash % (i3_blocks - i2_blocks); case 4 ... 19: return i3_blocks + 16 * (hash % (((1<<31) - i3_blocks) / 16)) + round - 4; } BUG();} static struct page *logfs_get_dd_page(struct inode *dir, struct dentry *dentry){ struct qstr *name = &dentry->d_name; struct page *page; struct logfs_disk_dentry *dd; u32 hash = hash_32(name->name, name->len, 0); pgoff_t index; int round; if (name->len > LOGFS_MAX_NAMELEN) return ERR_PTR(-ENAMETOOLONG); for (round = 0; round < 20; round++) { index = hash_index(hash, round); if (beyond_eof(dir, index)) return NULL; if (!logfs_exist_block(dir, index)) continue; page = read_cache_page(dir->i_mapping, index, (filler_t *)logfs_readpage, NULL); if (IS_ERR(page)) return page; dd = kmap_atomic(page); BUG_ON(dd->namelen == 0); if (name->len != be16_to_cpu(dd->namelen) || memcmp(name->name, dd->name, name->len)) { kunmap_atomic(dd); page_cache_release(page); continue; } kunmap_atomic(dd); return page; } return NULL;} static int logfs_remove_inode(struct inode *inode){ int ret; drop_nlink(inode); ret = write_inode(inode); LOGFS_BUG_ON(ret, inode->i_sb); return ret;} static void abort_transaction(struct inode *inode, struct logfs_transaction *ta){ if (logfs_inode(inode)->li_block) logfs_inode(inode)->li_block->ta = NULL; kfree(ta);} static int logfs_unlink(struct inode *dir, struct dentry *dentry){ struct logfs_super *super = logfs_super(dir->i_sb); struct inode *inode = dentry->d_inode; struct logfs_transaction *ta; struct page *page; pgoff_t index; int ret; ta = kzalloc(sizeof(*ta), GFP_KERNEL); if (!ta) return -ENOMEM; ta->state = UNLINK_1; ta->ino = inode->i_ino; inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; page = logfs_get_dd_page(dir, dentry); if (!page) { kfree(ta); return -ENOENT; } if (IS_ERR(page)) { kfree(ta); return PTR_ERR(page); } index = page->index; page_cache_release(page); mutex_lock(&super->s_dirop_mutex); logfs_add_transaction(dir, ta); ret = logfs_delete(dir, index, NULL); if (!ret) ret = write_inode(dir); if (ret) { abort_transaction(dir, ta); printk(KERN_ERR"LOGFS: unable to delete inode\n"); goto out; } ta->state = UNLINK_2; logfs_add_transaction(inode, ta); ret = logfs_remove_inode(inode);out: mutex_unlock(&super->s_dirop_mutex); return ret;} static inline int logfs_empty_dir(struct inode *dir){ u64 data; data = logfs_seek_data(dir, 0) << dir->i_sb->s_blocksize_bits; return data >= i_size_read(dir);} static int logfs_rmdir(struct inode *dir, struct dentry *dentry){ struct inode *inode = dentry->d_inode; if (!logfs_empty_dir(inode)) return -ENOTEMPTY; return logfs_unlink(dir, dentry);} /* FIXME: readdir currently has it's own dir_walk code. I don't see a good * way to combine the two copies */#define IMPLICIT_NODES 2static int __logfs_readdir(struct file *file, void *buf, filldir_t filldir){ struct inode *dir = file->f_dentry->d_inode; loff_t pos = file->f_pos - IMPLICIT_NODES; struct page *page; struct logfs_disk_dentry *dd; int full; BUG_ON(pos < 0); for (;; pos++) { if (beyond_eof(dir, pos)) break; if (!logfs_exist_block(dir, pos)) { /* deleted dentry */ pos = dir_seek_data(dir, pos); continue; } page = read_cache_page(dir->i_mapping, pos, (filler_t *)logfs_readpage, NULL); if (IS_ERR(page)) return PTR_ERR(page); dd = kmap(page); BUG_ON(dd->namelen == 0); full = filldir(buf, (char *)dd->name, be16_to_cpu(dd->namelen), pos, be64_to_cpu(dd->ino), dd->type); kunmap(page); page_cache_release(page); if (full) break; } file->f_pos = pos + IMPLICIT_NODES; return 0;} static int logfs_readdir(struct file *file, void *buf, filldir_t filldir){ struct inode *inode = file->f_dentry->d_inode; ino_t pino = parent_ino(file->f_dentry); int err; if (file->f_pos < 0) return -EINVAL; if (file->f_pos == 0) { if (filldir(buf, ".", 1, 1, inode->i_ino, DT_DIR) < 0) return 0; file->f_pos++; } if (file->f_pos == 1) { if (filldir(buf, "..", 2, 2, pino, DT_DIR) < 0) return 0; file->f_pos++; } err = __logfs_readdir(file, buf, filldir); return err;} static void logfs_set_name(struct logfs_disk_dentry *dd, struct qstr *name){ dd->namelen = cpu_to_be16(name->len); memcpy(dd->name, name->name, name->len);} static struct dentry *logfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd){ struct page *page; struct logfs_disk_dentry *dd; pgoff_t index; u64 ino = 0; struct inode *inode; page = logfs_get_dd_page(dir, dentry); if (IS_ERR(page)) return ERR_CAST(page); if (!page) { d_add(dentry, NULL); return NULL; } index = page->index; dd = kmap_atomic(page); ino = be64_to_cpu(dd->ino); kunmap_atomic(dd); page_cache_release(page); inode = logfs_iget(dir->i_sb, ino); if (IS_ERR(inode)) printk(KERN_ERR"LogFS: Cannot read inode #%llx for dentry (%lx, %lx)n", ino, dir->i_ino, index); return d_splice_alias(inode, dentry);} static void grow_dir(struct inode *dir, loff_t index){ index = (index + 1) << dir->i_sb->s_blocksize_bits; if (i_size_read(dir) < index) i_size_write(dir, index);} static int logfs_write_dir(struct inode *dir, struct dentry *dentry, struct inode *inode){ struct page *page; struct logfs_disk_dentry *dd; u32 hash = hash_32(dentry->d_name.name, dentry->d_name.len, 0); pgoff_t index; int round, err; for (round = 0; round < 20; round++) { index = hash_index(hash, round); if (logfs_exist_block(dir, index)) continue; page = find_or_create_page(dir->i_mapping, index, GFP_KERNEL); if (!page) return -ENOMEM; dd = kmap_atomic(page); memset(dd, 0, sizeof(*dd)); dd->ino = cpu_to_be64(inode->i_ino); dd->type = logfs_type(inode); logfs_set_name(dd, &dentry->d_name); kunmap_atomic(dd); err = logfs_write_buf(dir, page, WF_LOCK); unlock_page(page); page_cache_release(page); if (!err) grow_dir(dir, index); return err; } /* FIXME: Is there a better return value? In most cases neither * the filesystem nor the directory are full. But we have had * too many collisions for this particular hash and no fallback. */ return -ENOSPC;} static int __logfs_create(struct inode *dir, struct dentry *dentry, struct inode *inode, const char *dest, long destlen){ struct logfs_super *super = logfs_super(dir->i_sb); struct logfs_inode *li = logfs_inode(inode); struct logfs_transaction *ta; int ret; ta = kzalloc(sizeof(*ta), GFP_KERNEL); if (!ta) { drop_nlink(inode); iput(inode); return -ENOMEM; } ta->state = CREATE_1; ta->ino = inode->i_ino; mutex_lock(&super->s_dirop_mutex); logfs_add_transaction(inode, ta); if (dest) { /* symlink */ ret = logfs_inode_write(inode, dest, destlen, 0, WF_LOCK, NULL); if (!ret) ret = write_inode(inode); } else { /* creat/mkdir/mknod */ ret = write_inode(inode); } if (ret) { abort_transaction(inode, ta); li->li_flags |= LOGFS_IF_STILLBORN; /* FIXME: truncate symlink */ drop_nlink(inode); iput(inode); goto out; } ta->state = CREATE_2; logfs_add_transaction(dir, ta); ret = logfs_write_dir(dir, dentry, inode); /* sync directory */ if (!ret) ret = write_inode(dir); if (ret) { logfs_del_transaction(dir, ta); ta->state = CREATE_2; logfs_add_transaction(inode, ta); logfs_remove_inode(inode); iput(inode); goto out; } d_instantiate(dentry, inode);out: mutex_unlock(&super->s_dirop_mutex); return ret;} static int logfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode){ struct inode *inode; /* * FIXME: why do we have to fill in S_IFDIR, while the mode is * correct for mknod, creat, etc.? Smells like the vfs *should* * do it for us but for some reason fails to do so. */ inode = logfs_new_inode(dir, S_IFDIR | mode); if (IS_ERR(inode)) return PTR_ERR(inode); inode->i_op = &logfs_dir_iops; inode->i_fop = &logfs_dir_fops; Lines 1–500 of 820. Load more
/* * fs/logfs/dir.c - directory-related code * * As should be obvious for Linux kernel code, license is GPLv2 * * Copyright (c) 2005-2008 Joern Engel <joern@logfs.org> */ #include "logfs.h" #include <linux/slab.h> /* * Atomic dir operations * * Directory operations are by default not atomic. Dentries and Inodes are * created/removed/altered in separate operations. Therefore we need to do * a small amount of journaling. * * Create, link, mkdir, mknod and symlink all share the same function to do * the work: __logfs_create. This function works in two atomic steps: * 1. allocate inode (remember in journal) * 2. allocate dentry (clear journal) * * As we can only get interrupted between the two, when the inode we just * created is simply stored in the anchor. On next mount, if we were * interrupted, we delete the inode. From a users point of view the * operation never happened. * * Unlink and rmdir also share the same function: unlink. Again, this * function works in two atomic steps * 1. remove dentry (remember inode in journal) * 2. unlink inode (clear journal) * * And again, on the next mount, if we were interrupted, we delete the inode. * From a users point of view the operation succeeded. * * Rename is the real pain to deal with, harder than all the other methods * combined. Depending on the circumstances we can run into three cases. * A "target rename" where the target dentry already existed, a "local * rename" where both parent directories are identical or a "cross-directory * rename" in the remaining case. * * Local rename is atomic, as the old dentry is simply rewritten with a new * name. * * Cross-directory rename works in two steps, similar to __logfs_create and * logfs_unlink: * 1. Write new dentry (remember old dentry in journal) * 2. Remove old dentry (clear journal) * * Here we remember a dentry instead of an inode. On next mount, if we were * interrupted, we delete the dentry. From a users point of view, the * operation succeeded. * * Target rename works in three atomic steps: * 1. Attach old inode to new dentry (remember old dentry and new inode) * 2. Remove old dentry (still remember the new inode) * 3. Remove victim inode * * Here we remember both an inode an a dentry. If we get interrupted * between steps 1 and 2, we delete both the dentry and the inode. If * we get interrupted between steps 2 and 3, we delete just the inode. * In either case, the remaining objects are deleted on next mount. From * a users point of view, the operation succeeded. */ static int write_dir(struct inode *dir, struct logfs_disk_dentry *dd, loff_t pos) { return logfs_inode_write(dir, dd, sizeof(*dd), pos, WF_LOCK, NULL); } static int write_inode(struct inode *inode) { return __logfs_write_inode(inode, NULL, WF_LOCK); } static s64 dir_seek_data(struct inode *inode, s64 pos) { s64 new_pos = logfs_seek_data(inode, pos); return max(pos, new_pos - 1); } static int beyond_eof(struct inode *inode, loff_t bix) { loff_t pos = bix << inode->i_sb->s_blocksize_bits; return pos >= i_size_read(inode); } /* * Prime value was chosen to be roughly 256 + 26. r5 hash uses 11, * so short names (len <= 9) don't even occupy the complete 32bit name * space. A prime >256 ensures short names quickly spread the 32bit * name space. Add about 26 for the estimated amount of information * of each character and pick a prime nearby, preferably a bit-sparse * one. */ static u32 hash_32(const char *s, int len, u32 seed) { u32 hash = seed; int i; for (i = 0; i < len; i++) hash = hash * 293 + s[i]; return hash; } /* * We have to satisfy several conflicting requirements here. Small * directories should stay fairly compact and not require too many * indirect blocks. The number of possible locations for a given hash * should be small to make lookup() fast. And we should try hard not * to overflow the 32bit name space or nfs and 32bit host systems will * be unhappy. * * So we use the following scheme. First we reduce the hash to 0..15 * and try a direct block. If that is occupied we reduce the hash to * 16..255 and try an indirect block. Same for 2x and 3x indirect * blocks. Lastly we reduce the hash to 0x800_0000 .. 0xffff_ffff, * but use buckets containing eight entries instead of a single one. * * Using 16 entries should allow for a reasonable amount of hash * collisions, so the 32bit name space can be packed fairly tight * before overflowing. Oh and currently we don't overflow but return * and error. * * How likely are collisions? Doing the appropriate math is beyond me * and the Bronstein textbook. But running a test program to brute * force collisions for a couple of days showed that on average the * first collision occurs after 598M entries, with 290M being the * smallest result. Obviously 21 entries could already cause a * collision if all entries are carefully chosen. */ static pgoff_t hash_index(u32 hash, int round) { u32 i0_blocks = I0_BLOCKS; u32 i1_blocks = I1_BLOCKS; u32 i2_blocks = I2_BLOCKS; u32 i3_blocks = I3_BLOCKS; switch (round) { case 0: return hash % i0_blocks; case 1: return i0_blocks + hash % (i1_blocks - i0_blocks); case 2: return i1_blocks + hash % (i2_blocks - i1_blocks); case 3: return i2_blocks + hash % (i3_blocks - i2_blocks); case 4 ... 19: return i3_blocks + 16 * (hash % (((1<<31) - i3_blocks) / 16)) + round - 4; } BUG(); } static struct page *logfs_get_dd_page(struct inode *dir, struct dentry *dentry) { struct qstr *name = &dentry->d_name; struct page *page; struct logfs_disk_dentry *dd; u32 hash = hash_32(name->name, name->len, 0); pgoff_t index; int round; if (name->len > LOGFS_MAX_NAMELEN) return ERR_PTR(-ENAMETOOLONG); for (round = 0; round < 20; round++) { index = hash_index(hash, round); if (beyond_eof(dir, index)) return NULL; if (!logfs_exist_block(dir, index)) continue; page = read_cache_page(dir->i_mapping, index, (filler_t *)logfs_readpage, NULL); if (IS_ERR(page)) return page; dd = kmap_atomic(page); BUG_ON(dd->namelen == 0); if (name->len != be16_to_cpu(dd->namelen) || memcmp(name->name, dd->name, name->len)) { kunmap_atomic(dd); page_cache_release(page); continue; } kunmap_atomic(dd); return page; } return NULL; } static int logfs_remove_inode(struct inode *inode) { int ret; drop_nlink(inode); ret = write_inode(inode); LOGFS_BUG_ON(ret, inode->i_sb); return ret; } static void abort_transaction(struct inode *inode, struct logfs_transaction *ta) { if (logfs_inode(inode)->li_block) logfs_inode(inode)->li_block->ta = NULL; kfree(ta); } static int logfs_unlink(struct inode *dir, struct dentry *dentry) { struct logfs_super *super = logfs_super(dir->i_sb); struct inode *inode = dentry->d_inode; struct logfs_transaction *ta; struct page *page; pgoff_t index; int ret; ta = kzalloc(sizeof(*ta), GFP_KERNEL); if (!ta) return -ENOMEM; ta->state = UNLINK_1; ta->ino = inode->i_ino; inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; page = logfs_get_dd_page(dir, dentry); if (!page) { kfree(ta); return -ENOENT; } if (IS_ERR(page)) { kfree(ta); return PTR_ERR(page); } index = page->index; page_cache_release(page); mutex_lock(&super->s_dirop_mutex); logfs_add_transaction(dir, ta); ret = logfs_delete(dir, index, NULL); if (!ret) ret = write_inode(dir); if (ret) { abort_transaction(dir, ta); printk(KERN_ERR"LOGFS: unable to delete inode\n"); goto out; } ta->state = UNLINK_2; logfs_add_transaction(inode, ta); ret = logfs_remove_inode(inode); out: mutex_unlock(&super->s_dirop_mutex); return ret; } static inline int logfs_empty_dir(struct inode *dir) { u64 data; data = logfs_seek_data(dir, 0) << dir->i_sb->s_blocksize_bits; return data >= i_size_read(dir); } static int logfs_rmdir(struct inode *dir, struct dentry *dentry) { struct inode *inode = dentry->d_inode; if (!logfs_empty_dir(inode)) return -ENOTEMPTY; return logfs_unlink(dir, dentry); } /* FIXME: readdir currently has it's own dir_walk code. I don't see a good * way to combine the two copies */ #define IMPLICIT_NODES 2 static int __logfs_readdir(struct file *file, void *buf, filldir_t filldir) { struct inode *dir = file->f_dentry->d_inode; loff_t pos = file->f_pos - IMPLICIT_NODES; struct page *page; struct logfs_disk_dentry *dd; int full; BUG_ON(pos < 0); for (;; pos++) { if (beyond_eof(dir, pos)) break; if (!logfs_exist_block(dir, pos)) { /* deleted dentry */ pos = dir_seek_data(dir, pos); continue; } page = read_cache_page(dir->i_mapping, pos, (filler_t *)logfs_readpage, NULL); if (IS_ERR(page)) return PTR_ERR(page); dd = kmap(page); BUG_ON(dd->namelen == 0); full = filldir(buf, (char *)dd->name, be16_to_cpu(dd->namelen), pos, be64_to_cpu(dd->ino), dd->type); kunmap(page); page_cache_release(page); if (full) break; } file->f_pos = pos + IMPLICIT_NODES; return 0; } static int logfs_readdir(struct file *file, void *buf, filldir_t filldir) { struct inode *inode = file->f_dentry->d_inode; ino_t pino = parent_ino(file->f_dentry); int err; if (file->f_pos < 0) return -EINVAL; if (file->f_pos == 0) { if (filldir(buf, ".", 1, 1, inode->i_ino, DT_DIR) < 0) return 0; file->f_pos++; } if (file->f_pos == 1) { if (filldir(buf, "..", 2, 2, pino, DT_DIR) < 0) return 0; file->f_pos++; } err = __logfs_readdir(file, buf, filldir); return err; } static void logfs_set_name(struct logfs_disk_dentry *dd, struct qstr *name) { dd->namelen = cpu_to_be16(name->len); memcpy(dd->name, name->name, name->len); } static struct dentry *logfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { struct page *page; struct logfs_disk_dentry *dd; pgoff_t index; u64 ino = 0; struct inode *inode; page = logfs_get_dd_page(dir, dentry); if (IS_ERR(page)) return ERR_CAST(page); if (!page) { d_add(dentry, NULL); return NULL; } index = page->index; dd = kmap_atomic(page); ino = be64_to_cpu(dd->ino); kunmap_atomic(dd); page_cache_release(page); inode = logfs_iget(dir->i_sb, ino); if (IS_ERR(inode)) printk(KERN_ERR"LogFS: Cannot read inode #%llx for dentry (%lx, %lx)n", ino, dir->i_ino, index); return d_splice_alias(inode, dentry); } static void grow_dir(struct inode *dir, loff_t index) { index = (index + 1) << dir->i_sb->s_blocksize_bits; if (i_size_read(dir) < index) i_size_write(dir, index); } static int logfs_write_dir(struct inode *dir, struct dentry *dentry, struct inode *inode) { struct page *page; struct logfs_disk_dentry *dd; u32 hash = hash_32(dentry->d_name.name, dentry->d_name.len, 0); pgoff_t index; int round, err; for (round = 0; round < 20; round++) { index = hash_index(hash, round); if (logfs_exist_block(dir, index)) continue; page = find_or_create_page(dir->i_mapping, index, GFP_KERNEL); if (!page) return -ENOMEM; dd = kmap_atomic(page); memset(dd, 0, sizeof(*dd)); dd->ino = cpu_to_be64(inode->i_ino); dd->type = logfs_type(inode); logfs_set_name(dd, &dentry->d_name); kunmap_atomic(dd); err = logfs_write_buf(dir, page, WF_LOCK); unlock_page(page); page_cache_release(page); if (!err) grow_dir(dir, index); return err; } /* FIXME: Is there a better return value? In most cases neither * the filesystem nor the directory are full. But we have had * too many collisions for this particular hash and no fallback. */ return -ENOSPC; } static int __logfs_create(struct inode *dir, struct dentry *dentry, struct inode *inode, const char *dest, long destlen) { struct logfs_super *super = logfs_super(dir->i_sb); struct logfs_inode *li = logfs_inode(inode); struct logfs_transaction *ta; int ret; ta = kzalloc(sizeof(*ta), GFP_KERNEL); if (!ta) { drop_nlink(inode); iput(inode); return -ENOMEM; } ta->state = CREATE_1; ta->ino = inode->i_ino; mutex_lock(&super->s_dirop_mutex); logfs_add_transaction(inode, ta); if (dest) { /* symlink */ ret = logfs_inode_write(inode, dest, destlen, 0, WF_LOCK, NULL); if (!ret) ret = write_inode(inode); } else { /* creat/mkdir/mknod */ ret = write_inode(inode); } if (ret) { abort_transaction(inode, ta); li->li_flags |= LOGFS_IF_STILLBORN; /* FIXME: truncate symlink */ drop_nlink(inode); iput(inode); goto out; } ta->state = CREATE_2; logfs_add_transaction(dir, ta); ret = logfs_write_dir(dir, dentry, inode); /* sync directory */ if (!ret) ret = write_inode(dir); if (ret) { logfs_del_transaction(dir, ta); ta->state = CREATE_2; logfs_add_transaction(inode, ta); logfs_remove_inode(inode); iput(inode); goto out; } d_instantiate(dentry, inode); out: mutex_unlock(&super->s_dirop_mutex); return ret; } static int logfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { struct inode *inode; /* * FIXME: why do we have to fill in S_IFDIR, while the mode is * correct for mknod, creat, etc.? Smells like the vfs *should* * do it for us but for some reason fails to do so. */ inode = logfs_new_inode(dir, S_IFDIR | mode); if (IS_ERR(inode)) return PTR_ERR(inode); inode->i_op = &logfs_dir_iops; inode->i_fop = &logfs_dir_fops;