X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=lustre%2Fllite%2Flproc_llite.c;h=35676f2bf5de2520773cd0b6a12de90608ffca15;hp=0c342151746cb5d023ca5429451427d9e8a73148;hb=cbd3a230274e1197d378725ee9e2aed6e35d2cb6;hpb=05ea8d2b4ce1b6794bc12d78bae9cfe1608cb4d3

diff --git a/lustre/llite/lproc_llite.c b/lustre/llite/lproc_llite.c
index 0c34215..35676f2 100644
--- a/lustre/llite/lproc_llite.c
+++ b/lustre/llite/lproc_llite.c
@@ -21,155 +21,620 @@
  */
 #define DEBUG_SUBSYSTEM S_LLITE
 
+#include <linux/version.h>
 #include <linux/lustre_lite.h>
 #include <linux/lprocfs_status.h>
+#include <linux/seq_file.h>
+#include <linux/obd_support.h>
 
+#include "llite_internal.h"
 
+/* /proc/lustre/llite mount point registration */
+struct proc_dir_entry *proc_lustre_fs_root;
+struct file_operations llite_dump_pgcache_fops;
 
-int rd_path(char* page, char **start, off_t off,
-               int count, int *eof, void *data)
+#ifndef LPROCFS
+int lprocfs_register_mountpoint(struct proc_dir_entry *parent,
+                                struct super_block *sb, char *osc, char *mdc)
 {
-        
         return 0;
+}
+void lprocfs_unregister_mountpoint(struct ll_sb_info *sbi){}
+#else
+
+long long mnt_instance;
+
+static int ll_rd_blksize(char *page, char **start, off_t off, int count,
+                         int *eof, void *data)
+{
+        struct super_block *sb = (struct super_block *)data;
+        struct obd_statfs osfs;
+        int rc;
+
+        LASSERT(sb != NULL);
+        rc = ll_statfs_internal(sb, &osfs, jiffies - HZ);
+        if (!rc) {
+              *eof = 1;
+              rc = snprintf(page, count, "%u\n", osfs.os_bsize);
+        }
+
+        return rc;
+}
+
+static int ll_rd_kbytestotal(char *page, char **start, off_t off, int count,
+                             int *eof, void *data)
+{
+        struct super_block *sb = (struct super_block *)data;
+        struct obd_statfs osfs;
+        int rc;
+
+        LASSERT(sb != NULL);
+        rc = ll_statfs_internal(sb, &osfs, jiffies - HZ);
+        if (!rc) {
+                __u32 blk_size = osfs.os_bsize >> 10;
+                __u64 result = osfs.os_blocks;
+
+                while (blk_size >>= 1)
+                        result <<= 1;
+
+                *eof = 1;
+                rc = snprintf(page, count, LPU64"\n", result);
+        }
+        return rc;
+
+}
+
+static int ll_rd_kbytesfree(char *page, char **start, off_t off, int count,
+                            int *eof, void *data)
+{
+        struct super_block *sb = (struct super_block *)data;
+        struct obd_statfs osfs;
+        int rc;
+
+        LASSERT(sb != NULL);
+        rc = ll_statfs_internal(sb, &osfs, jiffies - HZ);
+        if (!rc) {
+                __u32 blk_size = osfs.os_bsize >> 10;
+                __u64 result = osfs.os_bfree;
+
+                while (blk_size >>= 1)
+                        result <<= 1;
+
+                *eof = 1;
+                rc = snprintf(page, count, LPU64"\n", result);
+        }
+        return rc;
+}
+
+static int ll_rd_kbytesavail(char *page, char **start, off_t off, int count,
+                             int *eof, void *data)
+{
+        struct super_block *sb = (struct super_block *)data;
+        struct obd_statfs osfs;
+        int rc;
+
+        LASSERT(sb != NULL);
+        rc = ll_statfs_internal(sb, &osfs, jiffies - HZ);
+        if (!rc) {
+                __u32 blk_size = osfs.os_bsize >> 10;
+                __u64 result = osfs.os_bavail;
+
+                while (blk_size >>= 1)
+                        result <<= 1;
+
+                *eof = 1;
+                rc = snprintf(page, count, LPU64"\n", result);
+        }
+        return rc;
+}
+
+static int ll_rd_filestotal(char *page, char **start, off_t off, int count,
+                            int *eof, void *data)
+{
+        struct super_block *sb = (struct super_block *)data;
+        struct obd_statfs osfs;
+        int rc;
+
+        LASSERT(sb != NULL);
+        rc = ll_statfs_internal(sb, &osfs, jiffies - HZ);
+        if (!rc) {
+                 *eof = 1;
+                 rc = snprintf(page, count, LPU64"\n", osfs.os_files);
+        }
+        return rc;
+}
+
+static int ll_rd_filesfree(char *page, char **start, off_t off, int count,
+                           int *eof, void *data)
+{
+        struct super_block *sb = (struct super_block *)data;
+        struct obd_statfs osfs;
+        int rc;
 
+        LASSERT(sb != NULL);
+        rc = ll_statfs_internal(sb, &osfs, jiffies - HZ);
+        if (!rc) {
+                 *eof = 1;
+                 rc = snprintf(page, count, LPU64"\n", osfs.os_ffree);
+        }
+        return rc;
+
+}
+
+static int ll_rd_fstype(char *page, char **start, off_t off, int count,
+                        int *eof, void *data)
+{
+        struct super_block *sb = (struct super_block*)data;
+
+        LASSERT(sb != NULL);
+        *eof = 1;
+        return snprintf(page, count, "%s\n", sb->s_type->name);
+}
+
+static int ll_rd_sb_uuid(char *page, char **start, off_t off, int count,
+                         int *eof, void *data)
+{
+        struct super_block *sb = (struct super_block *)data;
+
+        LASSERT(sb != NULL);
+        *eof = 1;
+        return snprintf(page, count, "%s\n", ll_s2sbi(sb)->ll_sb_uuid.uuid);
+}
+
+static int ll_rd_read_ahead(char *page, char **start, off_t off, int count,
+                            int *eof, void *data)
+{
+        struct super_block *sb = (struct super_block*)data;
+        struct ll_sb_info *sbi = ll_s2sbi(sb);
+        int val, rc;
+        ENTRY;
+
+        *eof = 1;
+        val = (sbi->ll_flags & LL_SBI_READAHEAD) ? 1 : 0;
+        rc = snprintf(page, count, "%d\n", val);
+        RETURN(rc);
+}
+
+static int ll_wr_read_ahead(struct file *file, const char *buffer,
+                            unsigned long count, void *data)
+{
+        struct super_block *sb = (struct super_block*)data;
+        struct ll_sb_info *sbi = ll_s2sbi(sb);
+        int readahead;
+        ENTRY;
+
+        if (1 != sscanf(buffer, "%d", &readahead))
+                RETURN(-EINVAL);        
+
+        if (readahead)
+                sbi->ll_flags |= LL_SBI_READAHEAD;
+        else
+                sbi->ll_flags &= ~LL_SBI_READAHEAD;
+
+        RETURN(count);
+}
+
+static int ll_rd_max_read_ahead_mb(char *page, char **start, off_t off, 
+                                   int count, int *eof, void *data)
+{
+        struct super_block *sb = data;
+        struct ll_sb_info *sbi = ll_s2sbi(sb);
+        unsigned val;
+
+        spin_lock(&sbi->ll_lock);
+        val = (sbi->ll_max_read_ahead_pages << PAGE_CACHE_SHIFT) >> 20;
+        spin_unlock(&sbi->ll_lock);
+
+        return snprintf(page, count, "%u\n", val);
 }
-int rd_fstype(char* page, char **start, off_t off,
-                int count, int *eof, void *data)
-{
-        int len=0;
-        struct super_block *sb=(struct super_block*)data;
-        
-        len+=snprintf(page, count, "%s\n", sb->s_type->name); 
-        return len;
-}
-int rd_blksize(char* page, char **start, off_t off,
-               int count, int *eof, void *data)
-{
-        int len=0;
-        struct super_block *sb=(struct super_block*)data;
-        struct statfs mystats;
-        (sb->s_op->statfs)(sb, &mystats);
-        len+=snprintf(page, count, LPU64"\n", (__u64)(mystats.f_bsize)); 
-        return len;
-
-}
-int rd_kbytestotal(char* page, char **start, off_t off,
-                int count, int *eof, void *data)
-{
-        int len=0;
-        struct super_block *sb=(struct super_block*)data;
-        struct statfs mystats;
-        (sb->s_op->statfs)(sb, &mystats);
-        len+=snprintf(page, count, LPU64"\n", (__u64)(mystats.f_blocks)); 
-        return len;
-        
-}
-
-int rd_blkfree(char* page, char **start, off_t off,
-               int count, int *eof, void *data)
-{
-        int len=0;
-        struct super_block *sb=(struct super_block*)data;
-        struct statfs mystats;
-        (sb->s_op->statfs)(sb, &mystats);
-        len+=snprintf(page, count, LPU64"\n", (__u64)(mystats.f_bfree)); 
-        return len;
-        
-        
-}
-
-int rd_kbytesfree(char* page, char **start, off_t off,
-                  int count, int *eof, void *data)
-{
-        int len=0;
-        struct super_block *sb=(struct super_block*)data;
-        struct statfs mystats; 
-        long blk_size=0;
-        
-        (sb->s_op->statfs)(sb, &mystats);
-        blk_size=mystats.f_bsize;
-        
-        len+=snprintf(page, count, LPU64"\n", 
-                      (__u64)((mystats.f_bfree)/(blk_size*1024))); 
-        return len; 
-        
-}
-
-int rd_filestotal(char* page, char **start, off_t off,
-                  int count, int *eof, void *data)
-{
-        
-        int len=0;
-        struct super_block *sb=(struct super_block*)data;
-        
-        struct statfs mystats; 
-        
-        
-        (sb->s_op->statfs)(sb, &mystats);
-                
-        len+=snprintf(page, count, LPU64"\n", (__u64)(mystats.f_files)); 
-        return len;
-}
-
-int rd_filesfree(char* page, char **start, off_t off,
-               int count, int *eof, void *data)
-{
-        
-        int len=0;
-        struct super_block *sb=(struct super_block*)data;
-        
-        struct statfs mystats; 
-        
-        
-        (sb->s_op->statfs)(sb, &mystats);
-                
-        len+=snprintf(page, count, LPU64"\n", (__u64)(mystats.f_ffree)); 
-        return len;
-}
-
-int rd_filegroups(char* page, char **start, off_t off,
-                 int count, int *eof, void *data)
+
+static int ll_wr_max_read_ahead_mb(struct file *file, const char *buffer,
+                                   unsigned long count, void *data)
 {
+        struct super_block *sb = data;
+        struct ll_sb_info *sbi = ll_s2sbi(sb);
+        int val, rc;
+
+        rc = lprocfs_write_helper(buffer, count, &val);
+        if (rc)
+                return rc;
+
+        if (val < 0 || val > (num_physpages << PAGE_SHIFT) >> 20)
+                return -ERANGE;
+
+        spin_lock(&sbi->ll_lock);
+        sbi->ll_max_read_ahead_pages = (val << 20) >> PAGE_CACHE_SHIFT;
+        spin_unlock(&sbi->ll_lock);
+
+        return count;
+}
+
+static struct lprocfs_vars lprocfs_obd_vars[] = {
+        { "uuid",         ll_rd_sb_uuid,          0, 0 },
+        //{ "mntpt_path",   ll_rd_path,             0, 0 },
+        { "fstype",       ll_rd_fstype,           0, 0 },
+        { "blocksize",    ll_rd_blksize,          0, 0 },
+        { "kbytestotal",  ll_rd_kbytestotal,      0, 0 },
+        { "kbytesfree",   ll_rd_kbytesfree,       0, 0 },
+        { "kbytesavail",  ll_rd_kbytesavail,      0, 0 },
+        { "filestotal",   ll_rd_filestotal,       0, 0 },
+        { "filesfree",    ll_rd_filesfree,        0, 0 },
+        //{ "filegroups",   lprocfs_rd_filegroups,  0, 0 },
+        { "read_ahead",   ll_rd_read_ahead, ll_wr_read_ahead, 0 },
+        { "max_read_ahead_mb",   ll_rd_max_read_ahead_mb, 
+                                 ll_wr_max_read_ahead_mb, 0 },
+        { 0 }
+};
+
+#define MAX_STRING_SIZE 128
+
+struct llite_file_opcode {
+        __u32       opcode;
+        __u32       type;
+        const char *opname;
+} llite_opcode_table[LPROC_LL_FILE_OPCODES] = {
+        /* file operation */
+        { LPROC_LL_DIRTY_HITS,     LPROCFS_TYPE_REGS, "dirty_pages_hits" },
+        { LPROC_LL_DIRTY_MISSES,   LPROCFS_TYPE_REGS, "dirty_pages_misses" },
+        { LPROC_LL_WB_WRITEPAGE,   LPROCFS_CNTR_AVGMINMAX|LPROCFS_TYPE_PAGES,
+                                   "writeback_from_writepage" },
+        { LPROC_LL_WB_PRESSURE,    LPROCFS_CNTR_AVGMINMAX|LPROCFS_TYPE_PAGES,
+                                   "writeback_from_pressure" },
+        { LPROC_LL_WB_OK,          LPROCFS_CNTR_AVGMINMAX|LPROCFS_TYPE_PAGES,
+                                   "writeback_ok_pages" },
+        { LPROC_LL_WB_FAIL,        LPROCFS_CNTR_AVGMINMAX|LPROCFS_TYPE_PAGES,
+                                   "writeback_failed_pages" },
+        { LPROC_LL_READ_BYTES,     LPROCFS_CNTR_AVGMINMAX|LPROCFS_TYPE_BYTES,
+                                   "read_bytes" },
+        { LPROC_LL_WRITE_BYTES,    LPROCFS_CNTR_AVGMINMAX|LPROCFS_TYPE_BYTES,
+                                   "write_bytes" },
+        { LPROC_LL_BRW_READ,       LPROCFS_CNTR_AVGMINMAX|LPROCFS_TYPE_PAGES,
+                                   "brw_read" },
+        { LPROC_LL_BRW_WRITE,      LPROCFS_CNTR_AVGMINMAX|LPROCFS_TYPE_PAGES,
+                                   "brw_write" },
+
+        { LPROC_LL_IOCTL,          LPROCFS_TYPE_REGS, "ioctl" },
+        { LPROC_LL_OPEN,           LPROCFS_TYPE_REGS, "open" },
+        { LPROC_LL_RELEASE,        LPROCFS_TYPE_REGS, "close" },
+        { LPROC_LL_MAP,            LPROCFS_TYPE_REGS, "mmap" },
+        { LPROC_LL_LLSEEK,         LPROCFS_TYPE_REGS, "seek" },
+        { LPROC_LL_FSYNC,          LPROCFS_TYPE_REGS, "fsync" },
+        /* inode operation */
+        { LPROC_LL_SETATTR,        LPROCFS_TYPE_REGS, "setattr" },
+        { LPROC_LL_TRUNC,          LPROCFS_TYPE_REGS, "punch" },
+#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
+        { LPROC_LL_GETATTR,        LPROCFS_TYPE_REGS, "getattr" },
+#else
+        { LPROC_LL_REVALIDATE,     LPROCFS_TYPE_REGS, "getattr" },
+#endif
+        /* special inode operation */
+        { LPROC_LL_STAFS,          LPROCFS_TYPE_REGS, "statfs" },
+        { LPROC_LL_ALLOC_INODE,    LPROCFS_TYPE_REGS, "alloc_inode" },
+        { LPROC_LL_DIRECT_READ,    LPROCFS_CNTR_AVGMINMAX|LPROCFS_TYPE_PAGES,
+                                   "direct_read" },
+        { LPROC_LL_DIRECT_WRITE,   LPROCFS_CNTR_AVGMINMAX|LPROCFS_TYPE_PAGES,
+                                   "direct_write" },
+
+};
+
+int lprocfs_register_mountpoint(struct proc_dir_entry *parent,
+                                struct super_block *sb, char *osc, char *mdc)
+{
+        struct lprocfs_vars lvars[2];
+        struct ll_sb_info *sbi = ll_s2sbi(sb);
+        struct obd_device *obd;
+        char name[MAX_STRING_SIZE + 1];
+        int err, id;
+        struct lprocfs_stats *svc_stats = NULL;
+        struct proc_dir_entry *entry;
+        ENTRY;
+
+        memset(lvars, 0, sizeof(lvars));
+
+        name[MAX_STRING_SIZE] = '\0';
+        lvars[0].name = name;
+
+        LASSERT(sbi != NULL);
+        LASSERT(mdc != NULL);
+        LASSERT(osc != NULL);
+
+        /* Mount info */
+        snprintf(name, MAX_STRING_SIZE, "fs%llu", mnt_instance);
+
+        mnt_instance++;
+        sbi->ll_proc_root = lprocfs_register(name, parent, NULL, NULL);
+        if (IS_ERR(sbi->ll_proc_root)) {
+                err = PTR_ERR(sbi->ll_proc_root);
+                sbi->ll_proc_root = NULL;
+                RETURN(err);
+        }
+
+        entry = create_proc_entry("dump_page_cache", 0444, sbi->ll_proc_root);
+        if (entry == NULL)
+                GOTO(out, err = -ENOMEM);
+        entry->proc_fops = &llite_dump_pgcache_fops;
+        entry->data = sbi;
+
+        svc_stats = lprocfs_alloc_stats(LPROC_LL_FILE_OPCODES);
+        if (svc_stats == NULL) {
+                err = -ENOMEM;
+                goto out;
+        }
+        /* do counter init */
+        for (id = 0; id < LPROC_LL_FILE_OPCODES; id++) {
+                __u32 type = llite_opcode_table[id].type;
+                void *ptr = NULL;
+                if (type & LPROCFS_TYPE_REGS)
+                        ptr = "regs";
+                else {
+                        if (type & LPROCFS_TYPE_BYTES)
+                                ptr = "bytes";
+                        else {
+                                if (type & LPROCFS_TYPE_PAGES)
+                                        ptr = "pages";
+                        }
+                }
+                lprocfs_counter_init(svc_stats, llite_opcode_table[id].opcode,
+                                     (type & LPROCFS_CNTR_AVGMINMAX),
+                                     llite_opcode_table[id].opname, ptr);
+        }
+        err = lprocfs_register_stats(sbi->ll_proc_root, "stats", svc_stats);
+        if (err)
+                goto out;
+        else
+                sbi->ll_stats = svc_stats;
+        /* need place to keep svc_stats */
+
+        /* Static configuration info */
+        err = lprocfs_add_vars(sbi->ll_proc_root, lprocfs_obd_vars, sb);
+        if (err)
+                goto out;
+
+        /* MDC info */
+        obd = class_name2obd(mdc);
+
+        LASSERT(obd != NULL);
+        LASSERT(obd->obd_type != NULL);
+        LASSERT(obd->obd_type->typ_name != NULL);
+
+        snprintf(name, MAX_STRING_SIZE, "%s/common_name",
+                 obd->obd_type->typ_name);
+        lvars[0].read_fptr = lprocfs_rd_name;
+        err = lprocfs_add_vars(sbi->ll_proc_root, lvars, obd);
+        if (err)
+                goto out;
+
+        snprintf(name, MAX_STRING_SIZE, "%s/uuid", obd->obd_type->typ_name);
+        lvars[0].read_fptr = lprocfs_rd_uuid;
+        err = lprocfs_add_vars(sbi->ll_proc_root, lvars, obd);
+        if (err)
+                goto out;
+
+        /* OSC */
+        obd = class_name2obd(osc);
+
+        LASSERT(obd != NULL);
+        LASSERT(obd->obd_type != NULL);
+        LASSERT(obd->obd_type->typ_name != NULL);
+
+        snprintf(name, MAX_STRING_SIZE, "%s/common_name",
+                 obd->obd_type->typ_name);
+        lvars[0].read_fptr = lprocfs_rd_name;
+        err = lprocfs_add_vars(sbi->ll_proc_root, lvars, obd);
+        if (err)
+                goto out;
+
+        snprintf(name, MAX_STRING_SIZE, "%s/uuid", obd->obd_type->typ_name);
+        lvars[0].read_fptr = lprocfs_rd_uuid;
+        err = lprocfs_add_vars(sbi->ll_proc_root, lvars, obd);
+out:
+        if (err) {
+                if (svc_stats)
+                        lprocfs_free_stats(svc_stats);
+                if (sbi->ll_proc_root)
+                        lprocfs_remove(sbi->ll_proc_root);
+        }
+        RETURN(err);
+}
+
+void lprocfs_unregister_mountpoint(struct ll_sb_info *sbi)
+{
+        if (sbi->ll_proc_root) {
+                struct proc_dir_entry *file_stats =
+                        lprocfs_srch(sbi->ll_proc_root, "stats");
+
+                if (file_stats) {
+                        lprocfs_free_stats(sbi->ll_stats);
+                        lprocfs_remove(file_stats);
+                }
+        }
+}
+#undef MAX_STRING_SIZE
+
+static struct ll_async_page *llite_pglist_next_llap(struct ll_sb_info *sbi,
+                                                    struct list_head *list)
+{
+        struct ll_async_page *llap;
+        struct list_head *pos;
+
+        list_for_each(pos, list) {
+                if (pos == &sbi->ll_pglist)
+                        return NULL;
+                llap = list_entry(pos, struct ll_async_page, llap_proc_item);
+                if (llap->llap_page == NULL)
+                        continue;
+                return llap;
+        }
+        LBUG();
+        return NULL;
+}
+
+#define seq_page_flag(seq, page, flag, has_flags) do {                  \
+                if (test_bit(PG_##flag, &(page)->flags)) {              \
+                        if (!has_flags)                                 \
+                                has_flags = 1;                          \
+                        else                                            \
+                                seq_putc(seq, '|');                     \
+                        seq_puts(seq, #flag);                           \
+                }                                                       \
+        } while(0);
+
+static int llite_dump_pgcache_seq_show(struct seq_file *seq, void *v)
+{
+        struct ll_async_page *llap, *dummy_llap = seq->private;
+        struct ll_sb_info *sbi = dummy_llap->llap_cookie;
+
+        /* 2.4 doesn't seem to have SEQ_START_TOKEN, so we implement
+         * it in our own state */
+        if (dummy_llap->llap_magic == 0) {
+                seq_printf(seq, "generation | llap .cookie | page ");
+                seq_printf(seq, "inode .index [ page flags ]\n");
+                return 0;
+        }
+
+        spin_lock(&sbi->ll_lock);
+
+        llap = llite_pglist_next_llap(sbi, &dummy_llap->llap_proc_item);
+        if (llap != NULL)  {
+                int has_flags = 0;
+                struct page *page = llap->llap_page;
+
+                seq_printf(seq, "%lu | %p %p | %p %p %lu [", 
+                                sbi->ll_pglist_gen, 
+                                llap, llap->llap_cookie,
+                                page, page->mapping->host, page->index);
+                seq_page_flag(seq, page, locked, has_flags);
+                seq_page_flag(seq, page, error, has_flags);
+                seq_page_flag(seq, page, referenced, has_flags);
+                seq_page_flag(seq, page, uptodate, has_flags);
+                seq_page_flag(seq, page, dirty, has_flags);
+                seq_page_flag(seq, page, highmem, has_flags);
+                if (!has_flags)
+                        seq_puts(seq, "-]\n");
+                else 
+                        seq_puts(seq, "]\n");
+        }
+
+        spin_unlock(&sbi->ll_lock);
+
         return 0;
 }
-int rd_uuid(char* page, char **start, off_t off,
-            int count, int *eof, void *data)
+
+static void *llite_dump_pgcache_seq_start(struct seq_file *seq, loff_t *pos)
 {
-        int len=0;
-        struct super_block *sb=(struct super_block*)data;
-        struct ll_sb_info *sbi=ll_s2sbi(sb);
-        len+=snprintf(page, count, "%s\n", sbi->ll_sb_uuid); 
-        return len;    
+        struct ll_async_page *llap = seq->private;
 
+        if (llap->llap_magic == 2)
+                return NULL;
+
+        return (void *)1;
 }
-int rd_dev_name(char* page, char **start, off_t off,
-                    int count, int *eof, void *data)
+
+static void *llite_dump_pgcache_seq_next(struct seq_file *seq, void *v, 
+                                         loff_t *pos)
 {
-        int len=0;
-        struct obd_device* dev=(struct obd_device*)data;
-        len+=snprintf(page, count, "%s\n", dev->obd_name);
-        return len;
+        struct ll_async_page *llap, *dummy_llap = seq->private;
+        struct ll_sb_info *sbi = dummy_llap->llap_cookie;
+
+        /* bail if we just displayed the banner */
+        if (dummy_llap->llap_magic == 0) {
+                dummy_llap->llap_magic = 1;
+                return dummy_llap;
+        }
+
+        /* we've just displayed the llap that is after us in the list.
+         * we advance to a position beyond it, returning null if there
+         * isn't another llap in the list beyond that new position. */
+        spin_lock(&sbi->ll_lock);
+        llap = llite_pglist_next_llap(sbi, &dummy_llap->llap_proc_item);
+        list_del_init(&dummy_llap->llap_proc_item);
+        if (llap) {
+                list_add(&dummy_llap->llap_proc_item, &llap->llap_proc_item);
+                llap = llite_pglist_next_llap(sbi, &dummy_llap->llap_proc_item);
+        }
+        spin_unlock(&sbi->ll_lock);
+
+        ++*pos;
+        if (llap == NULL) {
+                dummy_llap->llap_magic = 2;
+                return NULL;
+        }
+        return dummy_llap;
 }
 
-int rd_dev_uuid(char* page, char **start, off_t off,
-                    int count, int *eof, void *data)
+static void llite_dump_pgcache_seq_stop(struct seq_file *seq, void *v)
 {
-        int len=0;
-        struct obd_device* dev=(struct obd_device*)data;
-        len+=snprintf(page, count, "%s\n", dev->obd_uuid);
-        return len;
 }
 
+struct seq_operations llite_dump_pgcache_seq_sops = {
+        .start = llite_dump_pgcache_seq_start,
+        .stop = llite_dump_pgcache_seq_stop,
+        .next = llite_dump_pgcache_seq_next,
+        .show = llite_dump_pgcache_seq_show,
+};
 
-struct lprocfs_vars status_var_nm_1[]={
-        {"status/uuid", rd_uuid, 0},
-        {"status/mntpt_path", rd_path, 0},
-        {"status/fs_type", rd_fstype, 0},
-        {"status/blocksize",rd_blksize, 0},
-        {"status/kbytestotal",rd_kbytestotal, 0},
-        {"status/kbytesfree", rd_kbytesfree, 0},
-        {"status/filestotal", rd_filestotal, 0},
-        {"status/filesfree", rd_filesfree, 0},
-        {"status/filegroups", rd_filegroups, 0},
-        {0}
+/* we're displaying llaps in a list_head list.  we don't want to hold a lock
+ * while we walk the entire list, and we don't want to have to seek into
+ * the right position in the list as an app advances with many syscalls.  we
+ * allocate a dummy llap and hang it off file->private.  its position in
+ * the list records where the app is currently displaying.  this way our
+ * seq .start and .stop don't actually do anything.  .next returns null
+ * when the dummy hits the end of the list which eventually leads to .release
+ * where we tear down.  this kind of displaying is super-racey, so we put
+ * a generation counter on the list so the output shows when the list
+ * changes between reads.
+ */
+static int llite_dump_pgcache_seq_open(struct inode *inode, struct file *file)
+{
+        struct proc_dir_entry *dp = PDE(inode);
+        struct ll_async_page *llap;
+        struct seq_file *seq;
+        struct ll_sb_info *sbi = dp->data;
+        int rc;
+
+        OBD_ALLOC_GFP(llap, sizeof(*llap), GFP_KERNEL);
+        if (llap == NULL)
+                return -ENOMEM;
+        llap->llap_page = NULL;
+        llap->llap_cookie = sbi;
+        llap->llap_magic = 0;
+
+        rc = seq_open(file, &llite_dump_pgcache_seq_sops);
+        if (rc) {
+                OBD_FREE(llap, sizeof(*llap));
+                return rc;
+        }
+        seq = file->private_data;
+        seq->private = llap;
+
+        spin_lock(&sbi->ll_lock);
+        list_add(&llap->llap_proc_item, &sbi->ll_pglist);
+        spin_unlock(&sbi->ll_lock);
+
+        return 0;
+}
+
+static int llite_dump_pgcache_seq_release(struct inode *inode,
+                                          struct file *file)
+{
+        struct seq_file *seq = file->private_data;
+        struct ll_async_page *llap = seq->private;
+        struct ll_sb_info *sbi = llap->llap_cookie;
+
+        spin_lock(&sbi->ll_lock);
+        if (!list_empty(&llap->llap_proc_item))
+                list_del_init(&llap->llap_proc_item);
+        spin_unlock(&sbi->ll_lock);
+        OBD_FREE(llap, sizeof(*llap));
+
+        return seq_release(inode, file);
+}
+
+struct file_operations llite_dump_pgcache_fops = {
+        .owner   = THIS_MODULE,
+        .open    = llite_dump_pgcache_seq_open,
+        .read    = seq_read,
+        .release = llite_dump_pgcache_seq_release,
 };
+
+#endif /* LPROCFS */